U.S. patent application number 14/877008 was filed with the patent office on 2016-01-28 for ionic liquids as lubricating oil base stocks, cobase stocks and multifunctional functional fluids.
This patent application is currently assigned to EXXONMOBIL RESEARCH AND ENGINEERING COMPANY. The applicant listed for this patent is Satish Bodige, Tezcan Guney, Abhimanyu Onkar Patil. Invention is credited to Satish Bodige, Tezcan Guney, Abhimanyu Onkar Patil.
Application Number | 20160024414 14/877008 |
Document ID | / |
Family ID | 49709845 |
Filed Date | 2016-01-28 |
United States Patent
Application |
20160024414 |
Kind Code |
A1 |
Patil; Abhimanyu Onkar ; et
al. |
January 28, 2016 |
IONIC LIQUIDS AS LUBRICATING OIL BASE STOCKS, COBASE STOCKS AND
MULTIFUNCTIONAL FUNCTIONAL FLUIDS
Abstract
A composition including an ionic liquid alkylammonium salt
(e.g., tetraalkylammonium cation and bis(2-ethylhexyl) phosphate
anion), or an ionic liquid imidazolium salt (e.g.,
1,3-dialkylimidazolium cation and bis(2-ethylhexyl) phosphate
anion), that have a structure sufficient to exhibit at least
partial solubility in one or more Group I-V base stocks. The
disclosure also relates to a lubricating oil base stock and
lubricating oil containing the composition, a multifunctional
functional fluid containing the composition, and a method for
improving solubility of an ionic liquid in a lubricating oil by
using as the lubricating oil a formulated oil including a
lubricating oil base stock as a major component, and an ionic
liquid alkylammonium salt cobase stock, or an ionic liquid
imidazolium salt cobase stock, as a minor component.
Inventors: |
Patil; Abhimanyu Onkar;
(Westfield, NJ) ; Bodige; Satish; (Wayne, NJ)
; Guney; Tezcan; (Ames, IA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Patil; Abhimanyu Onkar
Bodige; Satish
Guney; Tezcan |
Westfield
Wayne
Ames |
NJ
NJ
IA |
US
US
US |
|
|
Assignee: |
EXXONMOBIL RESEARCH AND ENGINEERING
COMPANY
Annandale
NJ
|
Family ID: |
49709845 |
Appl. No.: |
14/877008 |
Filed: |
October 7, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14080191 |
Nov 14, 2013 |
|
|
|
14877008 |
|
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|
61737158 |
Dec 14, 2012 |
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Current U.S.
Class: |
508/286 ;
508/283; 508/436 |
Current CPC
Class: |
C10M 2203/1006 20130101;
C10N 2030/54 20200501; C10M 171/00 20130101; C10M 2215/2245
20130101; C10M 2215/044 20130101; C10N 2020/01 20200501; C10M
105/74 20130101; C10M 111/02 20130101; C10M 133/46 20130101; C10M
2223/043 20130101; C10M 2203/1025 20130101; C10M 2223/04 20130101;
C10N 2040/02 20130101; C10M 137/08 20130101; C10M 2223/0405
20130101; C10M 2205/0285 20130101; C10M 111/04 20130101; C10M
2215/04 20130101; C10M 2207/2825 20130101; C10M 137/02 20130101;
C10M 2215/041 20130101; C10M 2205/223 20130101; C10M 2215/224
20130101; C10N 2030/06 20130101; C10N 2030/08 20130101; C10N
2020/077 20200501; C10M 2203/1025 20130101; C10N 2020/02 20130101;
C10M 2203/1025 20130101; C10N 2020/02 20130101 |
International
Class: |
C10M 133/46 20060101
C10M133/46; C10M 137/02 20060101 C10M137/02 |
Claims
1-8. (canceled)
9. A lubricating oil comprising a lubricating oil base stock as a
major component, and an ionic liquid alkylammonium salt cobase
stock or an ionic liquid imidazolium salt cobase stock, as a minor
component; wherein said ionic liquid alkylammonium salt is
represented by the formula
R.sub.4N.sup.+,[C.sub.8H.sub.17O].sub.2P(O).sub.2.sup.- (1) wherein
R is independently C.sub.1 to C.sub.16 straight chain alkyl,
branched chain alkyl, cycloalkyl, alkyl substituted cycloalkyl,
cycloalkyl substituted alkyl, or, optionally, two R groups comprise
a cyclic structure including the nitrogen atom and 4 to 12 carbon
atoms; wherein said ionic liquid alkylammonium salt has a structure
sufficient to exhibit at least partial solubility in one or more
Group I-V base stocks; and said ionic liquid imidazolium salt is
represented by the formula ##STR00024## wherein R.sup.1 and R.sup.3
are independently a C.sub.1 to C.sub.24 straight chain or branched
chain alkyl group, a C.sub.6 to C.sub.10 aryl group, a C.sub.7 to
C.sub.12 arylalkyl group, a C.sub.7 to C.sub.12 alkylaryl group, a
C.sub.2 to C.sub.8 alkenyl group, a C.sub.1 to C.sub.8 alkoxy
group, a C.sub.2 to C.sub.8 alkinyl group, or a C.sub.2 to C.sub.8
acyl group; and R.sup.2, R.sup.4 and R.sup.5 are hydrogen; wherein
said ionic liquid imidazolium salt has a structure sufficient to
exhibit at least partial solubility in one or more Group I-V base
stocks.
10. The lubricating oil of claim 9 wherein the lubricating oil base
stock comprises a Group I, II, III, IV or V base oil stock.
11. The lubricating oil of claim 9 wherein the lubricating oil base
stock is present in an amount from 50 weight percent to 99 weight
percent, and the ionic liquid alkylammonium salt cobase stock or
the ionic liquid imidazolium salt cobase stock is present in an
amount from 1 weight percent to 50 weight percent, based on the
total weight of the lubricating oil.
12. The lubricating oil of claim 9 wherein the cobase stock is
represented by the formula ##STR00025## ##STR00026##
13. The lubricating oil of claim 9 wherein, in formula (1), R is
independently C.sub.3H.sub.7, C.sub.4H.sub.9, C.sub.5H.sub.11,
C.sub.6H.sub.13, C.sub.8H.sub.17, C.sub.10H.sub.21,
C.sub.12H.sub.25, C.sub.14H.sub.29, or C.sub.16H.sub.33; and
wherein, in formula (2), R.sup.1 is CH.sub.3, C.sub.2H.sub.5,
C.sub.3H.sub.7, C.sub.4H.sub.9, C.sub.5H.sub.11, C.sub.6H.sub.13,
C.sub.8H.sub.17, C.sub.10H.sub.21, or C.sub.12H.sub.25, and R.sup.3
is C.sub.10H.sub.21, C.sub.12H.sub.25, C.sub.14H.sub.29,
C.sub.16H.sub.33, C.sub.18H.sub.37, or C.sub.20H.sub.41.
14. The lubricating oil of claim 9 wherein said ionic liquid
alkylammonium salt of formula (1) has a solubility in one or more
Group I-V base stocks of at least 5%, and said ionic liquid
imidazolium salt of formula (2) has a solubility in one or more
Group I-V base stocks of at least 5%.
15. The lubricating oil of claim 9 wherein the lubricating oil
further comprises one or more of a viscosity improver, antioxidant,
detergent, dispersant, pour point depressant, corrosion inhibitor,
metal deactivator, seal compatibility additive, anti-foam agent,
inhibitor, and anti-rust additive.
16-20. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional
Application Ser. No. 61/737,158 filed Dec. 14, 2012, herein
incorporated by reference in its entirety.
FIELD
[0002] This disclosure relates to compositions that include an
ionic liquid alkylammonium salt (e.g., tetraalkylammonium cation
and bis(2-ethylhexyl) phosphate anion), or an ionic liquid
imidazolium salt (e.g., 1,3-dialkylimidazolium cation and
bis(2-ethylhexyl) phosphate anion), a lubricating oil base stock
and lubricating oil containing the composition, a multifunctional
functional fluid containing the composition, and a method for
improving solubility of an ionic liquid in a lubricating oil by
using as the lubricating oil a formulated oil comprising a
lubricating oil base stock as a major component, and an ionic
liquid alkylammonium salt cobase stock, or an ionic liquid
imidazolium salt cobase stock, as a minor component.
BACKGROUND
[0003] Ionic liquids are useful as solvents in chemical synthesis,
electrochemistry, and other applications due to their ultra-low
vapor pressure, non-flammability, and high thermal stability. Ionic
liquids are comprised of ions. Conventional ionic liquids include
those where the cation is 1-alkyl-3-methylimidazolium,
N-alkylpyridinium, or tetraalkylphosphonium. The organic cations,
which are generally relatively large compared with simple inorganic
cations, account for the low melting points of the salts. Anions
range from simple inorganic anions to large complex anions. The
synthesis process does not involve high pressures (usually ambient
air) or high temperatures (usually 60-80.degree. C.).
[0004] Ionic liquids have features that make them attractive for
tribological applications, including negligible volatility,
non-flammability, high thermal stability, and better intrinsic
performance. These characteristics may avoid the need to add
expensive additives to facilitate lubrication, as in the case of
conventional mineral-oil-based lubricants. Detergents may not be
necessary because ionic liquids act as solvents, defoamers may not
be necessary due to the ultra-low vapor pressure of ionic liquids,
anti-oxidants may not be necessary due to the high thermal
stability of ionic liquids, and anti-wear additives may not be
necessary if ionic liquids form boundary lubricating films.
[0005] Limited publications have shown the potential for using
ionic liquids as a new class of lubricants. U.S. Pat. No. 7,754,664
discloses a lubricant or lubricant additive that is an ionic liquid
alkylammonium salt. The alkylammonium salt composition comprises an
ionic liquid alkylammonium salt represented by the formula
R.sub.xNH.sub.(4-x).sup.+,[F.sub.3C(CF.sub.2).sub.yS(O).sub.2].sub.2N.sup-
.- where x is 1 to 3, wherein R is independently C.sub.1 to
C.sub.12 straight chain alkyl, branched chain alkyl, cycloalkyl,
alkyl substituted cycloalkyl, cycloalkyl substituted alkyl, or,
optionally, when x is greater than 1, two R groups comprise a
cyclic structure including the nitrogen atom and 4 to 12 carbon
atoms, and y is independently 0 to 11.
[0006] Ammonium salts of partial esters of phosphoric and
thiophosphoric acids are commercially available as extreme pressure
and antiwear additives for lubricants and are disclosed in U.S.
Pat. Nos. 5,464,549 and 5,942,470. Other patents disclosing
ammonium salts of other large anions for lubricants include U.S.
Pat. Nos. 3,951,973, 4,115,286 and 4,950,414 where the anions are
trithiocyanurate, bis[(mercaptohydrocarbyl)ethylenedioxy]borates,
and cyclophosphetane derivatives, respectively.
[0007] U.S. Patent Application Publication No. 2009/0270286
discloses a synthetic lubrication oil that comprises an ionic
liquid containing an organic cation selected from the group
consisting of an imidazolium cation, a pyridinium cation, a
quaternary ammonium cation and a quaternary phosphonium cation and
a bis(fluorosulfonyl)imide anion, and one comprising an ionic
liquid composition which comprises an ionic liquid (A) containing a
1-ethyl-3-methylimidazolium cation and an ionic liquid (B1)
containing a 1-methyl-3-propylimidazolium cation and/or an ionic
liquid (B2) containing a 1-methyl-3-isopropylimidazolium
cation.
[0008] However, there remains a need to develop ionic liquids that
exhibit superior lubricating properties as the primary lubricant or
as lubricant additives, and that also exhibit solubility in
conventional base stocks, e.g., Group I-V base stocks. Ionic
lubricants with anions that permit superior thermal stability are
also desirable for lubricants and lubricant additives.
[0009] In particular, there is a need for base stock which would be
suitable, for example, for special bearing applications such as for
operation at greater than 250.degree. C., where conventional
hydrocarbon lubricants start decomposing, but many ionic liquids
are stable. Most ionic liquids, however, have little to no
solubility (<1%) conventional base stocks, e.g., Group I-V base
stocks. Therefore, there is a present need to develop ionic liquids
with good solubility in nonpolar lubricating base oils.
[0010] The present disclosure provides many additional advantages,
which shall become apparent as described below.
SUMMARY
[0011] This disclosure relates in part to a composition
comprising:
[0012] (i) an ionic liquid alkylammonium salt represented by the
formula
R.sub.4N.sup.+,[C.sub.8H.sub.17O].sub.2P(O).sub.2.sup.- (1)
wherein R is independently hydrogen, C.sub.1 to C.sub.16 straight
chain alkyl, branched chain alkyl, cycloalkyl, alkyl substituted
cycloalkyl, cycloalkyl substituted alkyl, or, optionally, two R
groups comprise a cyclic structure including the nitrogen atom and
4 to 12 carbon atoms; wherein said ionic liquid alkylammonium salt
has a structure sufficient to exhibit at least partial solubility
in one or more Group I-V base stocks; or
[0013] (ii) an ionic liquid imidazolium salt represented by the
formula
##STR00001##
wherein R.sup.1 and R.sup.3 are independently a C.sub.1 to C.sub.24
straight chain or branched chain alkyl group, a C.sub.6 to C.sub.10
aryl group, a C.sub.7 to C.sub.12 arylalkyl group, a C.sub.7 to
C.sub.12 alkylaryl group, a C.sub.2 to C.sub.8 alkenyl group, a
C.sub.1 to C.sub.8 alkoxy group, a C.sub.2 to C.sub.8 alkinyl
group, or a C.sub.2 to C.sub.8 acyl group; and R.sup.2, R.sup.4 and
R.sup.5 are hydrogen; wherein said ionic liquid imidazolium salt
has a structure sufficient to exhibit at least partial solubility
in one or more Group I-V base stocks.
[0014] This disclosure also relates in part to a lubricating oil
base stock comprising:
[0015] (i) an ionic liquid alkylammonium salt represented by the
formula
R.sub.4N.sup.+,[C.sub.8H.sub.17O].sub.2P(O).sub.2.sup.- (1)
wherein R is independently C.sub.1 to C.sub.16 straight chain
alkyl, branched chain alkyl, cycloalkyl, alkyl substituted
cycloalkyl, cycloalkyl substituted alkyl, or, optionally, two R
groups comprise a cyclic structure including the nitrogen atom and
4 to 12 carbon atoms; wherein said ionic liquid alkylammonium salt
has a structure sufficient to exhibit at least partial solubility
in one or more Group I-V base stocks; or
[0016] (ii) an ionic liquid imidazolium salt represented by the
formula
##STR00002##
wherein R.sup.1 and R.sup.3 are independently a C.sub.1 to C.sub.24
straight chain or branched chain alkyl group, a C.sub.6 to C.sub.10
aryl group, a C.sub.7 to C.sub.12 arylalkyl group, a C.sub.7 to
C.sub.12 alkylaryl group, a C.sub.2 to C.sub.8 alkenyl group, a
C.sub.1 to C.sub.8 alkoxy group, a C.sub.2 to C.sub.8 alkinyl
group, or a C.sub.2 to C.sub.8 acyl group; and R.sup.2, R.sup.4 and
R.sup.5 are hydrogen; wherein said ionic liquid imidazolium salt
has a structure sufficient to exhibit at least partial solubility
in one or more Group I-V base stocks.
[0017] This disclosure further relates in part to a lubricating oil
comprising a lubricating oil base stock as a major component, and
an ionic liquid alkylammonium salt cobase stock or an ionic liquid
imidazolium salt cobase stock, as a minor component; wherein the
ionic liquid alkylammonium salt is represented by the formula
R.sub.4N.sup.+,[C.sub.8H.sub.17O].sub.2P(O).sub.2.sup.- (1)
wherein R is independently C.sub.1 to C.sub.16 straight chain
alkyl, branched chain alkyl, cycloalkyl, alkyl substituted
cycloalkyl, cycloalkyl substituted alkyl, or, optionally, two R
groups comprise a cyclic structure including the nitrogen atom and
4 to 12 carbon atoms; wherein said ionic liquid alkylammonium salt
has a structure sufficient to exhibit at least partial solubility
in one or more Group I-V base stocks; and said ionic liquid
imidazolium salt is represented by the formula
##STR00003##
wherein R.sup.1 and R.sup.3 are independently a C.sub.1 to C.sub.24
straight chain or branched chain alkyl group, a C.sub.6 to C.sub.10
aryl group, a C.sub.7 to C.sub.12 arylalkyl group, a C.sub.7 to
C.sub.12 alkylaryl group, a C.sub.2 to C.sub.8 alkenyl group, a
C.sub.1 to C.sub.8 alkoxy group, a C.sub.2 to C.sub.8 alkinyl
group, or a C.sub.2 to C.sub.8 acyl group; and R.sup.2, R.sup.4 and
R.sup.5 are hydrogen; wherein said ionic liquid imidazolium salt
has a structure sufficient to exhibit at least partial solubility
in one or more Group I-V base stocks.
[0018] This disclosure yet further relates in part to a
multifunctional functional fluid comprising:
[0019] (i) an ionic liquid alkylammonium salt represented by the
formula
R.sub.4N.sup.+,[C.sub.8H.sub.17O].sub.2P(O).sub.2.sup.- (1)
wherein R is independently C.sub.1 to C.sub.16 straight chain
alkyl, branched chain alkyl, cycloalkyl, alkyl substituted
cycloalkyl, cycloalkyl substituted alkyl, or, optionally, two R
groups comprise a cyclic structure including the nitrogen atom and
4 to 12 carbon atoms; wherein said ionic liquid alkylammonium salt
has a structure sufficient to exhibit at least partial solubility
in one or more Group I-V base stocks; or
[0020] (ii) an ionic liquid imidazolium salt represented by the
formula
##STR00004##
wherein R.sup.1 and R.sup.3 are independently a C.sub.1 to C.sub.24
straight chain or branched chain alkyl group, a C.sub.6 to C.sub.10
aryl group, a C.sub.7 to C.sub.12 arylalkyl group, a C.sub.7 to
C.sub.12 alkylaryl group, a C.sub.2 to C.sub.8 alkenyl group, a
C.sub.1 to C.sub.8 alkoxy group, a C.sub.2 to C.sub.8 alkinyl
group, or a C.sub.2 to C.sub.8 acyl group; and R.sup.2, R.sup.4 and
R.sup.5 are hydrogen; wherein said ionic liquid imidazolium salt
has a structure sufficient to exhibit at least partial solubility
in one or more Group I-V base stocks.
[0021] This disclosure also relates in part to a method for
improving solubility of an ionic liquid in a lubricating oil by
using as the lubricating oil a formulated oil comprising a
lubricating oil base stock as a major component, and an ionic
liquid alkylammonium salt cobase stock or an ionic liquid
imidazolium salt cobase stock, as a minor component; wherein the
ionic liquid alkylammonium salt is represented by the formula
R.sub.4N.sup.+,[C.sub.8H.sub.17O].sub.2P(O).sub.2.sup.- (1)
wherein R is independently C.sub.1 to C.sub.16 straight chain
alkyl, branched chain alkyl, cycloalkyl, alkyl substituted
cycloalkyl, cycloalkyl substituted alkyl, or, optionally, two R
groups comprise a cyclic structure including the nitrogen atom and
4 to 12 carbon atoms; wherein said ionic liquid alkylammonium salt
has a structure sufficient to exhibit at least partial solubility
in one or more Group I-V base stocks; and said ionic liquid
imidazolium salt is represented by the formula
##STR00005##
wherein R.sup.1 and R.sup.3 are independently a C.sub.1 to C.sub.24
straight chain or branched chain alkyl group, a C.sub.6 to C.sub.10
aryl group, a C.sub.7 to C.sub.12 arylalkyl group, a C.sub.7 to
C.sub.12 alkylaryl group, a C.sub.2 to C.sub.8 alkenyl group, a
C.sub.1 to C.sub.8 alkoxy group, a C.sub.2 to C.sub.8 alkinyl
group, or a C.sub.2 to C.sub.8 acyl group; and R.sup.2, R.sup.4 and
R.sup.5 are hydrogen; wherein said ionic liquid imidazolium salt
has a structure sufficient to exhibit at least partial solubility
in one or more Group I-V base stocks.
[0022] In addition to improved solubility and dispersibility for
polar additives and/or sludge generated during service of
lubricating oils, improved fuel efficiency can also be attained in
an engine lubricated with a lubricating oil by using as the
lubricating oil a formulated oil in accordance with this
disclosure. The formulated oil comprises a lubricating oil base
stock as a major component, and an ionic liquid cobase stock as a
minor component. The lubricating oils of this disclosure are
particularly advantageous as passenger vehicle engine oil (PVEO)
products.
[0023] It has been surprisingly found that ionic liquids of this
disclosure based on a tetraalkyl ammonium cation and a
bis(2-ethylhexyl) phosphate anion or a 1,3-dialkyl imidazolium
cation and a bis(2-ethylhexyl) phosphate anion are soluble in
hydrocarbon and ester base stocks that can be used as synthetic
base stocks or cobase stocks. Most conventional ionic liquids are
polar and have little or no solubility (<1%) in nonpolar
hydrocarbon oils. The ionic liquids of this disclosure surprisingly
are highly soluble in most petroleum derived Group I-V, preferably
Group I-III, base stocks and synthetic base stocks such as PAO 4
and high viscosity mPAO150 cSt fluid.
[0024] 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
[0025] FIG. 1 sets forth properties of the ionic liquids of
Examples 2-5, 7 and 8 (i.e., Kv at 100.degree. C., Kv at 40.degree.
C., and viscosity index).
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.
Ionic Liquid Compositions as Base Stocks, Cobase Stocks and
Multifunctional Functional Fluids
[0027] As indicated above, the compositions of formula (1) of this
disclosure comprise an ionic liquid alkylammonium salt represented
by the formula
R.sub.4N.sup.+,[C.sub.8H.sub.17O].sub.2P(O).sub.2.sup.- (1)
wherein R is independently hydrogen, C.sub.1 to C.sub.16 straight
chain alkyl, branched chain alkyl, cycloalkyl, alkyl substituted
cycloalkyl, cycloalkyl substituted alkyl, or, optionally, two R
groups comprise a cyclic structure including the nitrogen atom and
4 to 12 carbon atoms; wherein said ionic liquid alkylammonium salt
has a structure sufficient to exhibit at least partial solubility
in one or more Group I-V base stocks.
[0028] Illustrative R substituents include, for example,
C.sub.3H.sub.7, C.sub.4H.sub.9, C.sub.5H.sub.11, C.sub.6H.sub.13,
C.sub.8H.sub.17, C.sub.10H.sub.21, C.sub.12H.sub.25,
C.sub.14H.sub.29, C.sub.16H.sub.33, and the like. The R
substituents can be the same or different.
[0029] The compositions of formula (1) of this disclosure have a
viscosity (Kv.sub.100) from 2 to 400 at 100.degree. C., and a
viscosity index (VI) from 100 to 300. As used herein, viscosity
(Kv.sub.100) is determined by ASTM D 445-01, and viscosity index
(VI) is determined by ASTM D 2270-93 (1998). The compositions of
formula (1) of this disclosure have a Noack volatility of no
greater than 20 percent, preferably no greater than 18 percent, and
more preferably no greater than 15 percent. As used herein, Noack
volatility is determined by ASTM D-5800.
[0030] Ionic liquids of formula (1) of this disclosure comprise
ammonium (e.g., tetraalkylammonium) salts with a bis(2-ethylhexyl)
phosphate anion. These ammonium salts display good viscosities for
lubricating surfaces at high and low temperatures. These salts
display good thermal stability relative to conventional motor oils
where the ionic liquid displays an onset of decomposition that is
greater than 250.degree. C. These salts display a solubility,
preferably at least 5% or greater, more preferably at least 10% or
greater, and most preferably at least 15% or greater, in one or
more Group I-V base stocks. The melting points of the salts are
low, generally below 25.degree. C.
[0031] The ammonium salts of formula (1) can be prepared by
conventional methods such as an ion exchange method or a metathesis
reaction can be applied. For instance, the ionic liquid can be
obtained by an anion exchange reaction using a halogenated salt of
an organic ammonium cation to be used and a bis(2-ethylhexyl)
phosphate anion. The halogen in the halogenated salt is exemplified
by chlorine or bromine.
[0032] Amounts of the halogenated salt of the organic ammonium
cation and the bis(2-ethylhexyl) phosphate anion to be used in the
above reaction are not specifically limited, and 0.5 to 2
equivalents, still preferably 0.8 to 1.2 equivalent of the
bis(2-ethylhexyl) phosphate anion relative to the halogenated salt
of the organic ammonium cation is preferable. In a case of over the
above range, economical effect tends to be lowered because the
amount over the range does not give influence upon a reaction
yield, and in a case of less than the range, on the other hand, a
large amount of non-reacted starting material remains to bring
tendency of lowering a reaction yield.
[0033] Illustrative ionic liquid alkylammonium salts of formula (1)
of this disclosure can be represented by the formulae
[C.sub.6H.sub.13].sub.4N.sup.+,[C.sub.8H.sub.17O].sub.2P(O).sub.2.sup.-
[C.sub.6H.sub.17].sub.4N.sup.+,[C.sub.8H.sub.17O].sub.2P(O).sub.2.sup.-
[C.sub.10H.sub.21].sub.4N.sup.+,[C.sub.8H.sub.17O].sub.2P(O).sub.2.sup.-
and
[C.sub.12H.sub.25].sub.4N.sup.+,[C.sub.8H.sub.17O].sub.2P(O).sub.2.sup.--
.
[0034] Preferred ionic liquid alkylammonium salts of formula (1) of
this disclosure include tetraoctylammonium bis(2-ethylhexyl)
phosphate having the formula
##STR00006##
tetradecylammonium bis(2-ethylhexyl) phosphate having the
formula
##STR00007##
tetradodecylammonium bis(2-ethylhexyl) phosphate having the
formula
##STR00008##
and the like.
[0035] As also indicated above, the compositions of formula (2) of
this disclosure comprise an ionic liquid imidazolium salt
represented by the formula
##STR00009##
wherein R.sup.1 and R.sup.3 are independently a C.sub.1 to C.sub.24
straight chain or branched chain alkyl group, a C.sub.6 to C.sub.10
aryl group, a C.sub.7 to C.sub.12 arylalkyl group, a C.sub.7 to
C.sub.12 alkylaryl group, a C.sub.2 to C.sub.8 alkenyl group, a
C.sub.1 to C.sub.8 alkoxy group, a C.sub.2 to C.sub.8 alkinyl
group, or a C.sub.2 to C.sub.8 acyl group; and R.sup.2, R.sup.4 and
R.sup.5 are hydrogen; wherein said ionic liquid imidazolium salt
has a structure sufficient to exhibit at least partial solubility
in one or more Group I-V base stocks.
[0036] The substituents R.sup.1 to R.sup.5 may each independently
be a hydrogen atom, a halogen atom, a straight chained or branched
alkyl group, an alkenyl group, an alkinyl group, an alkoxyl group
or an acyl group, which has 1 to 16 carbon atoms, or an amide
group, a cyano group, a nitro group, or an amino group, and the
alkyl group, the alkenyl group, the alkinyl group, the alkoxyl
group and the acyl group may contain a hetero atom selected from N,
S and O, and further may contain a conjugate or independent double
bond or triple bond.
[0037] In a case where the substituents R.sup.1 to R.sup.5 are an
alkyl group, an alkenyl group, an alkinyl group, an alkoxyl group
or an acyl group, a carbon atom number thereof is preferably 1 to
16, particularly preferably 1 to 12, and still particularly
preferably 1 to 10. Those substituents may be straight chained or
branched, and a carbon atom number over the above maximum value is
not preferable because of trend of viscosity increase by
intermolecular interaction on side chains.
[0038] The above alkyl group, alkenyl group, alkinyl group, alkoxyl
group and acyl group may contain a hetero atom selected from N, S
and O, and the number of the hetero atom to be contained is not
specifically limited. Further, they may contain a conjugate or
independent double bond or triple bond, and the number of those
unsaturated bonds is not specifically limited.
[0039] Those alkyl groups are specifically exemplified by a methyl
group, an ethyl group, a propyl group, an isopropyl group, a butyl
group, an isobutyl group, a secondary butyl group, a tertiary butyl
group, a pentyl group, a hexyl group, a cyclopropyl group, a
cyclopentyl group, a cyclohexyl group, etc. The alkenyl group is
exemplified by a vinyl group, an allyl group, an 1-propenyl group,
an isopropenyl group, a 2-butenyl group, an 1,3-butadienyl group, a
2-pentenyl group, a 2-hexenyl group, etc. Further, the alkinyl
group is exemplified by an ethynyl group, an 1-propinyl group, a
2-propinyl group, etc., and the alkoxyl group is exemplified by a
methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy
group, a t-butoxy group, etc., the acyl group is exemplified by an
acetyl group, a propionyl group, a butylyl group, a benzoyl group,
etc., and the amino group is exemplified by an N,N-dimethylamino
group, an N,N-diethylamino group, etc. From a viewpoint of
industrial use, easy decomposition by enzymes and increased
biodegrability are valuable, and thus an alkoxyl group, an acyl
group, an amide group, a cyano group, a nitro group, an amino
group, etc. can be mentioned.
[0040] As the imidazolium cation shown by the above formula (2),
1,3-substituted imidazolium cation, is preferably used from a
viewpoint of easy synthesis. The substituent in the derivatives may
be same or different, and a substituent which may contain a
multiple bond or a branched chain may be useful.
[0041] Preferably, R.sup.1 and R.sup.3 are independently a C.sub.1
to C.sub.24 straight chain or branched chain alkyl group, a C.sub.6
to C.sub.10 aryl group, a C.sub.7 to C.sub.12 arylalkyl group, a
C.sub.7 to C.sub.12 alkylaryl group, a C.sub.2 to C.sub.8 alkenyl
group, a C.sub.1 to C.sub.8 alkoxy group, a C.sub.2 to C.sub.8
alkinyl group, or a C.sub.2 to C.sub.8 acyl group. Preferably, at
least one of R.sup.1 and R.sup.3 is a C.sub.10 to C.sub.24 straight
chain or branched chain alkyl group. R.sup.2, R.sup.4 and R.sup.5
are preferably hydrogen.
[0042] The compositions of formula (2) of this disclosure have a
viscosity (Kv too) from 2 to 400 at 100.degree. C., and a viscosity
index (VI) from 100 to 300. As used herein, viscosity (Kv.sub.100)
is determined by ASTM D 445-01, and viscosity index (VI) is
determined by ASTM D 2270-93 (1998). The compositions of formula
(2) of this disclosure have a Noack volatility of no greater than
20 percent, preferably no greater than 18 percent, and more
preferably no greater than 15 percent. As used herein, Noack
volatility is determined by ASTM D-5800.
[0043] Ionic liquids of formula (2) of this disclosure comprise
imidazolium (e.g., 1,3-substituted imidazolium) salts with a
bis(2-ethylhexyl) phosphate anion. These imidazolium salts display
good viscosities for lubricating surfaces at high and low
temperatures. These salts display good thermal stability relative
to conventional motor oils where the ionic liquid displays an onset
of decomposition that is greater than 250.degree. C. These salts
display a solubility, preferably at least 5% or greater, more
preferably at least 10% or greater, and most preferably at least
15% or greater, in one or more Group I-V base stocks. The melting
points of the salts are low, generally below 25.degree. C.
[0044] The imidazolium salts of formula (2) can be prepared by
conventional methods such as an ion exchange method or a metathesis
reaction can be applied. For instance, the ionic liquid can be
obtained by an anion exchange reaction using a halogenated salt of
an organic imidazolium cation to be used and a bis(2-ethylhexyl)
phosphate anion. The halogen in the halogenated salt is exemplified
by chlorine or bromine.
[0045] Amounts of the halogenated salt of the organic imidazolium
cation and the bis(2-ethylhexyl) phosphate anion to be used in the
above reaction are not specifically limited, and 0.5 to 2
equivalents, still preferably 0.8 to 1.2 equivalent of the
bis(2-ethylhexyl) phosphate anion relative to the halogenated salt
of the organic imidazolium cation is preferable. In a case of over
the above range, economical effect tends to be lowered because the
amount over the range does not give influence upon a reaction
yield, and in a case of less than the range, on the other hand, a
large amount of non-reacted starting material remains to bring
tendency of lowering a reaction yield.
[0046] Illustrative ionic liquid imidazolium salts of formula (2)
of this disclosure include 1-methyl-3-decylimidazolium
bis(2-ethylhexyl) phosphate having the formula
##STR00010##
1-butyl-3-hexylimidazolium bis(2-ethylhexyl) phosphate having the
formula
##STR00011##
and the like.
[0047] The ionic liquids of this disclosure are organic salts (100%
ions) with a melting point below 100.degree. C. exhibiting no
measureable vapor pressure below thermal decomposition. The ionic
liquids are clear bright synthetic fluids with wide viscosity range
(from single digit to >100 cSt) at room temperature. They are
liquid over wide temperature range (often over 300.degree. C.), and
they don't evaporate like most other liquids. The ionic liquids
have low freeing points and their typical structures (ammonium,
imidazolium, pyrrolidium, pyridinium, phosphonium, etc.) looks like
surface interactive friction/wear type lube additive. Typical
properties of ionic liquids include liquid below 100.degree. C.,
100% ions (strongly polar), low viscosity, virtually no vapor
pressure, thermal and hydrolytic stability, non flammable,
regenerative, broad liquid range (>300.degree. C.), ionic liquid
properties (viscosity, acidity, basicity, density) can be tunable
using cations and anions, and the like.
[0048] Advantages of the ionic liquids of this disclosure include:
1) reduced parasitic energy losses by reducing friction, 2)
extended service life and maintenance cycle because of wear
reduction, 3) expanded high temperature lubricant usage because of
high thermal stability and 4) safer transportation and storage
because of non-flammability. Thus, the lubricants of this
disclosure can improve and replace many lubricants that are
currently being used with potential friction and wear
reduction.
[0049] Ionic liquids are currently in use, for example, in chemical
synthesis and separation, food science, cellulose processing, paint
formulations. Other potential uses of ionic liquids include, for
example, solvents, catalyst/supported catalyst/solvent for
catalyst, separation (e.g., gas absorbent/storage/extraction),
electrolytes, performance additives (e.g., plasticizers, dispersing
agents, compatibilizers, solubilizers, antistatic agents, and the
like.
[0050] The ionic liquid compositions of this disclosure exhibit
unique properties which result from the composite properties of the
wide variety of cations and anions. Ionic liquids differ from
inorganic salts. The ionic liquid has a significantly lower
symmetry. Furthermore, the charge of the cation as well as the
charge of the anion is distributed over a larger volume of the
molecule by resonance. As a consequence, the solidification of the
ionic liquid will take place at lower temperatures. In some cases,
especially if long aliphatic side chains are involved, a glass
transition is observed instead of a melting point.
[0051] The strong ionic (Coulomb-) interaction within the ionic
liquids of this disclosure results in a negligible vapor pressure
(unless decomposition occurs), a non-flammable substance, and in a
high thermally, mechanically as well as electrochemically stable
product. In addition to this desirable combination of properties,
the ionic liquids offer other favorable properties, for example,
very appealing solvent properties and immiscibility with water or
organic solvents that result in biphasic systems.
[0052] The choice of the cation has a strong impact on the
properties of the ionic liquid and will often define the stability.
The chemistry and functionality of the ionic liquid is, in general,
controlled by the choice of the anion. In accordance with this
disclosure, the possible combinations of organic cations and anions
allows for designing and fine-tuning physical and chemical
properties by introducing or combining structural motifs and,
thereby, making tailor-made materials and solutions possible.
[0053] The ionic liquid is primarily salt or mixture of salts which
melts below room temperature. Ionic liquids may be characterized by
the general formula Q.sup.+ A.sup.-, where is Q.sup.+ is quaternary
ammonium, quaternary phosphonium, quaternary sulfonium, and A.sup.-
is a negatively charged ion such as Cl.sup.-, Br.sup.-,
NO.sub.3.sup.-, BF.sub.4.sup.-, BCl.sub.4.sup.-, PF.sub.6.sup.-,
SbF.sub.6.sup.-, AlCl.sub.4.sup.-, CuCl.sub.2.sup.-,
FeCl.sub.3.sup.-, and the like.
[0054] The ionic liquids of this disclosure may provide more
significant friction reduction if used as neat basestock or
cobasestock. These fluids may establish a tribolayer that is
physically adsorbed onto and/or chemically react with the metal
surfaces to effectively reduce friction and wear under boundary
lubrication.
[0055] This disclosure provides lubricating oils useful as engine
oils and in other applications characterized by excellent solvency
characteristics. The lubricating oils are based on high quality
base stocks including a major portion of a hydrocarbon base fluid
such as a PAO or GTL with a secondary cobase stock component which
is an ionic liquid alkylammonium salt or an ionic liquid
imidazolium salt as described herein. The lubricating oil base
stock can be any oil boiling in the lube oil boiling range,
typically between 100 to 450.degree. C. In the present
specification and claims, the terms base oil(s) and base stock(s)
are used interchangeably.
[0056] In the lubricating oils of this disclosure, the lubricating
oil base stock is present in an amount from 50 weight percent to 99
weight percent, preferably from 55 weight percent to 95 weight
percent, and more preferably from 60 to 90 weight percent, and the
ionic liquid alkylammonium salt cobase stock or the ionic liquid
imidazolium salt cobase stock is present in an amount from 1 weight
percent to 50 weight percent, preferably from 5 weight percent to
45 weight percent, and more preferably from 10 to 60 weight
percent, based on the total weight of the lubricating oil.
[0057] 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.
[0058] 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 method D 2270-93 [1998]. VI is
related to kinematic viscosities measured at 40.degree. C. and
100.degree. C. using ASTM Method D 445-01.
[0059] This disclosure also provides multifunctional functional
fluids comprising an ionic liquid alkylammonium salt. The ionic
liquid alkylammonium salt is represented by the formula
R.sub.4N.sup.+,[C.sub.8H.sub.17O].sub.2P(O).sub.2.sup.- (1)
wherein R is independently C.sub.1 to C.sub.16 straight chain
alkyl, branched chain alkyl, cycloalkyl, alkyl substituted
cycloalkyl, cycloalkyl substituted alkyl, or, optionally, two R
groups comprise a cyclic structure including the nitrogen atom and
4 to 12 carbon atoms; wherein said ionic liquid alkylammonium salt
has a structure sufficient to exhibit at least partial solubility
in one or more Group I-V base stocks.
[0060] This disclosure further provides multifunctional functional
fluids comprising an ionic liquid imidazolium salt. The ionic
liquid imidazolium salt is represented by the formula
##STR00012##
wherein R.sup.1 and R.sup.3 are independently a C.sub.1 to C.sub.24
straight chain or branched chain alkyl group, a C.sub.6 to C.sub.10
aryl group, a C.sub.7 to C.sub.12 arylalkyl group, a C.sub.7 to
C.sub.12 alkylaryl group, a C.sub.2 to C.sub.8 alkenyl group, a
C.sub.1 to C.sub.8 alkoxy group, a C.sub.2 to C.sub.8 alkinyl
group, or a C.sub.2 to Ca acyl group; and R.sup.2, R.sup.4 and
R.sup.5 are hydrogen; wherein said ionic liquid imidazolium salt
has a structure sufficient to exhibit at least partial solubility
in one or more Group I-V base stocks.
[0061] For ionic liquid base stocks of this disclosure, the ionic
liquid alkylammonium salt base stock or the ionic liquid
imidazolium salt base stock is present in an amount from 50 weight
percent to 99 weight percent, preferably from 55 weight percent to
95 weight percent, and more preferably from 60 to 90 weight
percent, of the ionic liquid formulation. For ionic liquid
multifunctional functional fluids of this disclosure, the ionic
liquid alkylammonium salt base stock or the ionic liquid
imidazolium salt base stock is present in an amount from 50 weight
percent to 99 weight percent, preferably from 55 weight percent to
95 weight percent, and more preferably from 60 to 90 weight
percent, of the fluid.
Lubricating Oil Base Stocks
[0062] A wide range of lubricating oils is known in the art.
Lubricating oils that are useful in the present disclosure are both
natural oils and synthetic oils. Natural and synthetic oils (or
mixtures thereof) can be used unrefined, refined, or rerefined (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. Rerefined oils are
obtained by processes analogous to refined oils but using an oil
that has been previously used as a feed stock.
[0063] 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 80 to 120 and contain greater than 0.03% sulfur
and less than 90% saturates. Group 11 base stocks generally have a
viscosity index of between 80 to 120, and contain less than or
equal to 0.03% sulfur and greater than or equal to 90% saturates.
Group III stock generally has a viscosity index greater than 120
and contains less than or equal to 0.03% sulfur and greater than
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
[0064] Natural oils include animal oils, vegetable oils (castor oil
and lard oil, for example), and mineral oils. Animal and vegetable
oils possessing favorable thermal oxidative stability can be used.
Of the natural oils, mineral oils are preferred. Mineral oils vary
widely as to their crude source, for example, as to whether they
are paraffinic, naphthenic, or mixed paraffinic-naphthenic. Oils
derived from coal or shale are also useful 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.
[0065] 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.
[0066] 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.
[0067] Esters in a minor amount 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.
[0068] 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 4 carbon atoms, preferably
C.sub.5 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.
[0069] Esters should be used in a amount such that the improved
wear and corrosion resistance provided by the lubricating oils of
this disclosure are not adversely affected.
[0070] 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 20
or greater, preferably 30 or greater and mixtures of such base
stocks and/or base oils.
[0071] 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.
[0072] 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 2 mm.sup.2/s to 50 mm.sup.2/s (ASTM D445).
They are further characterized typically as having pour points of
-5.degree. C. to -40.degree. C. or lower (ASTM D97). They are also
characterized typically as having viscosity indices of 80 to 140 or
greater (ASTM D2270).
[0073] 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 10 ppm, and more
typically less than 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.
[0074] 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.
[0075] 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).
[0076] 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 II 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.
[0077] 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 10 ppm, and more typically less than
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.
[0078] The basestock component of the present lubricating oils will
typically be from 50 to 99 weight percent of the total composition
(all proportions and percentages set out in this specification are
by weight unless the contrary is stated) and more usually in the
range of 80 to 99 weight percent.
Other Additives
[0079] The formulated 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.
[0080] 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 Improvers
[0081] Viscosity improvers (also known as Viscosity Index
modifiers, and VI improvers) increase the viscosity of the oil
composition at elevated temperatures which increases film
thickness, while having limited effect on viscosity at low
temperatures.
[0082] Suitable viscosity improvers include high molecular weight
hydrocarbons, polyesters and viscosity index improver dispersants
that function as both a viscosity index improver and a dispersant.
Typical molecular weights of these polymers are between 10,000 to
1,000,000, more typically 20,000 to 500,000, and even more
typically between 50,000 and 200,000.
[0083] Examples of suitable viscosity improvers are polymers and
copolymers of methacrylate, butadiene, olefins, or alkylated
styrenes. Polyisobutylene is a commonly used viscosity index
improver. Another suitable viscosity index improver is
polymethacrylate (copolymers of various chain length alkyl
methacrylates, for example), some formulations of which also serve
as pour point depressants. Other suitable viscosity index improvers
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.
[0084] The amount of viscosity modifier may range from zero to 8 wt
%, preferably zero to 4 wt %, more preferably zero to 2 wt % based
on active ingredient and depending on the specific viscosity
modifier used.
Antioxidants
[0085] Typical antioxidant include phenolic antioxidants, aminic
antioxidants and oil-soluble copper complexes.
[0086] 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 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.
[0087] Generally, therefore, the phenolic anti-oxidant may be
represented by the general formula:
(R).sub.x--Ar--(OH).sub.y
where Ar is selected from the group consisting of:
##STR00013##
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.
[0088] Preferred phenolic antioxidant 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 antioxidants 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
##STR00014##
[0089] Phenolic type antioxidants 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.
[0090] The phenolic antioxidant can be employed in an amount in the
range of 0.1 to 3 wt %, preferably 1 to 3 wt %, more preferably 1.5
to 3 wt % on an active ingredient basis.
[0091] Aromatic amine antioxidants include phenyl-.alpha.-naphthyl
amine which is described by the following molecular structure:
##STR00015##
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.
[0092] Other aromatic amine antioxidants 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 20 carbon atoms, and
preferably contains from 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.
[0093] Typical aromatic amines anti-oxidants have alkyl substituent
groups of at least 6 carbon atoms. Examples of aliphatic groups
include hexyl, heptyl, octyl, nonyl, and decyl. Generally, the
aliphatic groups will not contain more than 14 carbon atoms. The
general types of such other additional amine antioxidants 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.
[0094] Another class of antioxidant 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 know to be particularly useful.
[0095] Such antioxidants may be used individually or as mixtures of
one or more types of antioxidants, the total amount employed being
an amount of 0.50 to 5 wt %, preferably 0.75 to 3 wt % (on an
as-received basis).
Detergents
[0096] In addition to the alkali or alkaline earth metal salicylate
detergent which is an essential component in the present
disclosure, other detergents may also be present. While such other
detergents can be present, it is preferred that the amount employed
be such as to not interfere with the synergistic effect
attributable to the presence of the salicylate. Therefore, most
preferably such other detergents are not employed.
[0097] If such additional detergents are present, they can include
alkali and alkaline earth metal phenates, sulfonates, carboxylates,
phosphonates and mixtures thereof. These supplemental detergents
can have total base number (TBN) ranging from neutral to highly
overbased, i.e. TBN of 0 to over 500, preferably 2 to 400, more
preferably 5 to 300, and they can be present either individually or
in combination with each other in an amount in the range of from 0
to 10 wt %, preferably 0.5 to 5 wt % (active ingredient) based on
the total weight of the formulated lubricating oil. As previously
stated, however, it is preferred that such other detergent not be
present in the formulation.
[0098] Such additional other detergents include by way of example
and not limitation calcium phenates, calcium sulfonates, magnesium
phenates, magnesium sulfonates and other related components
(including borated detergents).
Dispersants
[0099] 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.
[0100] 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.
[0101] 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.
[0102] 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.
[0103] 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 1:1 to 5:1.
[0104] 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.
[0105] 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.
[0106] 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 0.1 to 5 moles of boron per
mole of dispersant reaction product.
[0107] 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.
[0108] Typical high molecular weight aliphatic acid modified
Mannich condensation products can be prepared from high molecular
weight alkyl-substituted hydroxyaromatics or HN(R).sub.2
group-containing reactants.
[0109] 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.
[0110] 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.
[0111] 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.
[0112] 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.
[0113] 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
500 to 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 0.1 to 20 wt %, preferably 0.1 to 8 wt %, more
preferably 1 to 6 wt % (on an as-received basis) based on the
weight of the total lubricant.
Pour Point Depressants
[0114] 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 0.0 to 0.5 wt %,
preferably 0 to 0.3 wt %, more preferably 0.001 to 0.1 wt % on an
as-received basis.
Corrosion Inhibitors/Metal Deactivators
[0115] 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 0.01 to 5 wt %,
preferably 0.01 to 1.5 wt %, more preferably 0.01 to 0.2 wt %,
still more preferably 0.01 to 0.1 wt % (on an as-received basis)
based on the total weight of the lubricating oil composition.
Seal Compatibility Additives
[0116] 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 0.01 to 3 wt %, preferably 0.01 to 2 wt % on an
as-received basis.
Anti-Foam Agents
[0117] 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 0.5 wt %, more preferably 0.001 to 0.2 wt %,
still more preferably 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
[0118] 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 0.01
to 5 wt %, preferably 0.01 to 1.5 wt % on an as-received basis.
[0119] In addition to the ZDDP anti-wear additives which are
essential components of the present disclosure, other anti-wear
additives can be present, including zinc dithiocarbamates,
molybdenum dialkyldithiophosphates, molybdenum dithiocarbamates,
other organo molybdenum-nitrogen complexes, sulfurized olefins,
etc.
[0120] 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.
[0121] 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.
[0122] 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
[0123] All starting materials and solvents were purchased from
commercial sources and used without further purification. All
reactions were carried out in oven-dried glassware. .sup.1H and
.sup.13C NMR spectra were acquired in CDCl.sub.3 on a Bruker 400
MHz spectrometer. .sup.1H and .sup.13C chemical shifts (.delta.)
are given in ppm relative to the residual protonated chloroform
peak. Fourier transform infrared (FTIR) spectra were recorded on a
Nicolet Nexus 470 spectrometer.
Example 1
Synthesis of 1-methyl-3-decylimidazolium bromide
##STR00016##
[0125] To a solution of 1-methylimidazole (10.00 grams, 121.8 mmol)
in toluene (50 milliliters) was added 1-bromodecane (29.63 grams,
134.0 mmol) drop wise at room temperature. The reaction mixture was
refluxed for 12 hours. A white precipitate formed after cooling the
reaction mixture to room temperature. After filtration, the product
was washed with hexanes (4.times.50 milliliters). The isolated
product was then further dried in vacuum at 50.degree. C. for 2
hours to completely remove any residual solvents or moisture. The
product was obtained as a slightly yellow viscous liquid (35.1
grams, 95% yield). .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 10.38
(s, 1H); 7.51 (t, 1H); 7.35 (t, 1H); 4.28 (t, 2H); 4.09 (s, 3H);
1.87 (m, 2H); 1.31-1.19 (m, 14H); 0.82 (t, 3H). IR (film) 3139,
3064, 2955, 2924, 2854, 1571, 1466, 1378, 1170 cm.sup.-1.
Example 2
Synthesis of 1-methyl-3-decylimidazolium bis(2-ethylhexyl)
phosphate
##STR00017##
[0127] A solution of bis(2-ethylhexyl) phosphate (3.50 grams, 10.88
mmol) in 10 milliliters of acetone was added dropwise to a solution
of 1-methyl-3-decylimidazolium bromide (3.00 grams, 9.89 mmol) in
50 milliliters of acetone. The reaction mixture was stirred at room
temperature for 10 minutes after which a solution of sodium
hydroxide (0.45 grams, 10.88 mmol) in 10 milliliters of de-ionized
water was added dropwise. The resulting mixture was stirred at room
temperature for 16 hours. After the reaction was completed, acetone
was removed by rotary evaporation. Dichloromethane (50 milliliters)
was added and the organic layer was washed with de-ionized water
(2.times.20 milliliters). The organic layer was then dried over
MgSO.sub.4, filtered, and concentrated by rotary evaporation to
afford the ionic liquid as a clear liquid (4.84 grams, 90% yield).
.sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 10.94 (s, 1H); 7.20 (t,
1H); 7.12 (t, 1H); 4.27 (t, 2H); 4.07 (s, 3H); 3.74 (m, 4H); 1.85
(m, 2H); 1.55-1.19 (m, 32H); 0.86 (t, 15H). .sup.13C NMR (100 MHz,
CDCl.sub.3) .delta. 139.87, 123.28, 121.29, 67.48, 67.47, 49.81,
40.45, 40.37, 36.28, 31.75, 30.25, 30.10, 29.39, 29.33, 29.16,
29.01, 29.01, 26.26, 23.32, 23.07, 22.55, 14.03, 13.98, 10.91. IR
(film) 3143, 3059, 2963, 2874, 2859, 1572, 1463, 1379, 1338, 1241,
1177, 1091, 1058 cm.sup.-1.
Example 3
Synthesis of tetraoctylammonium bis(2-ethylhexyl) phosphate
##STR00018##
[0129] A solution of bis(2-ethylhexyl) phosphate (1.94 grams, 6.01
mmol) in 10 milliliters of acetone was added dropwise to a solution
of tetraoctylammonium bromide (3.00 grams, 5.47 mmol) in 50
milliliters of acetone at 35.degree. C. The reaction mixture was
then stirred at room temperature for 10 minutes after which a
solution of sodium hydroxide (0.24 grams, 6.01 mmol) in 10
milliliters of de-ionized water was added dropwise. The resulting
mixture was stirred at room temperature for 16 hours. After the
reaction was completed, acetone was removed by rotary evaporation.
Dichloromethane (40 milliliters) was added and the organic layer
was washed with de-ionized water (2.times.20 milliliters). The
organic layer was then dried over MgSO.sub.4, filtered, and
concentrated by rotary evaporation to afford the product as a clear
liquid (4.31 grams, 90% yield). .sup.1H NMR (400 MHz, CDCl.sub.3)
.delta. 3.70 (m, 4H); 3.35 (m, 8H); 1.66 (m, 8H); 1.56-1.18 (m,
58H); 0.88 (t, 24H). .sup.13C NMR (100 MHz, CDCl.sub.1) .delta.
67.36, 67.30, 58.95, 40.53, 40.45, 31.64, 30.15, 29.13, 29.10,
29.00, 26.39, 23.36, 23.18, 22.54, 22.23, 14.11, 13.98, 10.97. IR
(film) 2957, 2925, 2872, 2857, 1467, 1378, 1248, 1094, 1063
cm.sup.-1.
Example 4
Synthesis of tetradecylammonium bis(2-ethylhexyl) phosphate
##STR00019##
[0131] A solution of bis(2-ethylhexyl) phosphate (1.61 grams, 5.01
mmol) in 10 milliliters of acetone was added dropwise to a solution
of tetradecylammonium bromide (3.00 grams, 4.55 mmol) in 50
milliliters of acetone at 50.degree. C. until all components were
completely dissolved. The reaction mixture was then stirred for 10
minutes after which a solution of sodium hydroxide (0.20 grams,
5.01 mmol) in 10 milliliters of de-ionized water was added
dropwise. The resulting mixture was stirred at room temperature for
16 hours. After the reaction was completed, acetone was removed by
rotary evaporation. Dichloromethane (40 milliliters) was added and
the organic layer was washed with de-ionized water (2.times.20
milliliters). The organic layer was then dried over MgSO.sub.4,
filtered, and concentrated by rotary evaporation to afford the
product as a clear liquid (3.73 grams, 91% yield). .sup.1H NMR (400
MHz, CDCl.sub.3) .delta. 3.70 (m, 4H); 3.35 (m, 8H); 1.67 (m, 8H);
1.53-1.20 (m, 74H); 0.88 (t, 24H). .sup.13C NMR (100 MHz,
CDCl.sub.3) 67.47, 67.40, 59.05, 40.64, 40.56, 31.91, 30.26, 29.54,
29.48, 29.34, 29.29, 29.21, 26.50, 23.48, 23.29, 22.71, 22.33,
14.23, 14.12, 11.07. IR (film) 2946, 2925, 2884, 2867, 2368, 1421,
1412, 1327, 1173, 1087 cm.sup.-1.
Example 5
Synthesis of tetradodecylammonium bis(2-ethylhexyl) phosphate
##STR00020##
[0133] A solution of bis(2-ethylhexyl) phosphate (0.62 grams, 1.92
mmol) in 5.0 milliliters of acetone was added dropwise to a
solution of tetradecylammonium bromide (1.35 grams, 1.75 mmol) in
30 milliliters of acetone at 50.degree. C. until all components
were completely dissolved. The reaction mixture was then stirred
for 10 minutes after which a solution of sodium hydroxide (0.08
grams, 1.92 mmol) in 5 milliliters of de-ionized water was added
dropwise. The resulting mixture was stirred at room temperature for
16 hours. After the reaction was completed, acetone was removed by
rotary evaporation. Dichloromethane (30 milliliters) was added and
the organic layer was washed with de-ionized water (2.times.15
milliliters). The organic layer was then dried over MgSO.sub.4,
filtered, and concentrated by rotary evaporation to afford the
product as a waxy solid (1.59 grams, 90% yield). .sup.1H NMR (400
MHz, CDCl.sub.3) .delta. 3.69 (m, 4H); 3.35 (m, 8H); 1.65 (m, 8H);
1.55-1.21 (m, 90H); 0.88 (t, 24H). .sup.13C NMR (100 MHz,
CDCl.sub.3) .delta. 67.38, 67.32, 58.99, 40.54, 40.46, 31.87,
30.17, 29.60, 29.58, 29.50, 29.39, 29.30, 29.20, 29.12, 26.40,
23.37, 23.20, 22.64, 22.24, 14.13, 14.06, 10.99. IR (film) 2956,
2924, 2852, 1470, 1378, 1249, 1065 cm.sup.-1.
Example 6
Synthesis of 1-butyl-3-hexylimidazolium chloride
##STR00021##
[0135] To a solution of 1-butylimidazole (10.00 grams, 80.52 mmol)
in toluene (50 milliliters) was added 1-chlorohexane (12.62 grams,
104.6 mmol) dropwise at room temperature. The reaction mixture was
refluxed for 16 hours. After cooling to room temperature, toluene
was decanted and the crude product was washed with hexanes
(3.times.100 milliliters). The isolated product was then further
purified by vacuum distillation to completely remove any residual
solvents, moisture, and starting materials. The product was
obtained as a slightly yellow viscous liquid (17.74 grams, 90%
yield). .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 10.97 (s, 1H);
7.42 (t, 1H); 7.38 (t, 1H); 4.37 (q, 4H); 1.92 (m, 4H); 1.45-1.19
(m, 8H); 0.97 (t, 3H); 0.87 (t, 3H). .sup.13C NMR (100 MHz,
CDCl.sub.3) .delta. 137.20, 122.22, 122.07, 49.74, 49.47, 32.00,
30.86, 30.07, 25.65, 22.15, 19.24, 13.68, 13.24. IR (film) 3130,
3048, 2958, 2860, 1635, 1563, 1466, 1406, 1379, 1334, 1168, 1022
cm.sup.-1.
Example 7
Synthesis of 1-butyl-3-hexylimidazolium bis(2-ethylhexyl)
phosphate
##STR00022##
[0137] A solution of bis(2-ethylhexyl) phosphate (5.08 grams, 15.76
mmol) in 20 milliliters of acetone was added dropwise to a solution
of 1-butyl-3-hexylimidazolium chloride (3.00 grams, 14.33 mmol) in
50 milliliters of acetone. The reaction mixture was stirred at room
temperature for 10 minutes after which a solution of sodium
hydroxide (0.45 grams, 10.88 mmol) in 10 milliliters of de-ionized
water was added dropwise. The resulting mixture was stirred at room
temperature for 16 hours. After the reaction was completed, acetone
was removed by rotary evaporation. Dichloromethane (50 milliliters)
was added and the organic layer was washed with de-ionized water
(2.times.20 milliliters). The organic layer was then dried over
MgSO.sub.4, filtered, and concentrated by rotary evaporation to
afford the ionic liquid as a clear liquid (4.84 grams, 90% yield).
.sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 10.98 (s, 1H); 7.22 (t,
1H); 7.21 (t, 1H); 4.34 (q, 4H); 3.74 (m, 4H); 1.89 (m, 4H);
1.61-1.19 (m, 26H); 0.86 (t, 18H). .sup.13C NMR (100 MHz,
CDCl.sub.3) .delta. 139.43, 121.65, 121.52, 67.40, 67.38, 49.71,
49.42, 40.42, 40.35, 32.07, 31.09, 30.15, 30.05, 28.97, 25.86,
23.27, 23.02, 22.30, 19.37, 13.98, 13.78, 13.35, 10.85. IR (film)
3140, 2958, 2930, 2874, 2860, 1564, 1465, 1379, 1234, 1167,
1057.
Example 8
Synthesis of dihexadecyldimethylammonium bis(2-ethylhexyl)
phosphate
##STR00023##
[0139] A solution of bis(2-ethylhexyl) phosphate (1.85 grams, 5.74
mmol) in 10.0 milliliters of acetone was added dropwise to a
solution of dihexadecyldimethylammonium bromide (3.00 grams, 5.22
mmol) in 60 milliliters of acetone at 50.degree. C. until all
components were completely dissolved. The reaction mixture was then
stirred for 10 minutes after which a solution of sodium hydroxide
(0.23 grams, 5.74 mmol) in 5 milliliters of de-ionized water was
added dropwise. The resulting mixture was stirred at room
temperature for 16 hours. After the reaction was completed, acetone
was removed by rotary evaporation. Dichloromethane (40 milliliters)
was added and the organic layer was washed with de-ionized water
(2.times.20 milliliters). The organic layer was then dried over
MgSO.sub.4, filtered, and concentrated by rotary evaporation to
afford the product as a clear liquid (3.87 grams, 91% yield). 1H
NMR (400 MHz, CDCl.sub.3) .delta. 3.71 (m, 4H); 3.39 (m, 4H); 3.33
(s, 6H); 1.67 (m, 4H); 1.56-1.22 (m, 70H); 0.87 (m, 18H). .sup.13C
NMR (100 MHz, CDCl.sub.3) .delta. 67.44, 67.38, 63.13, 51.10,
40.54, 40.46, 31.88, 30.17, 29.65, 29.64, 29.63, 29.63, 29.62,
29.58, 29.48, 29.40, 29.32, 29.28, 29.09, 26.32, 23.38, 23.17,
22.76, 22.64, 14.11, 14.06, 10.98.
Example 9
Lube Properties and Thermal Stability of Ionic Liquids
[0140] The kinematic viscosity (Kv) of the ionic liquid products of
Examples 2-5, 7 and 8 was measured using ASTM standards D-445 and
reported at temperatures of 100.degree. C. (Kv at 100.degree. C.)
or 40.degree. C. (Kv at 40.degree. C.). The viscosity index (VI)
was measured according to ASTM standard D-2270 using the measured
kinematic viscosities for each product.
[0141] The ionic liquids of Examples 2 and 3 are greater than 50%
soluble in di(tridecyl) adipate ester and greater than 5% soluble
in AN (alkylated naphthalene). The ionic liquid of Example 4 is
high viscosity fluid (Kv.sub.100>150 cSt) and is soluble in AN,
polyalphaolefin 4 (PAO4) and metallocene catalyst based
polyalphaolefin (mPAO)150 (>50% soluble). The ionic liquid of
Example 7 is soluble in di(tridecyl) adipate ester (50%) and AN
(5%). The ionic liquid of Example 8 is soluble in PAO4 and
mPAO150.
[0142] The ionic liquids of this disclosure can be used as base
stocks or can be blended with other base stocks (Group I-III, GTL,
PAO, AN, esters, PAGs). The ionic liquids of this disclosure can
also be used in formulations with other lube additives.
[0143] 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.
[0144] 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.
[0145] 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