Note: Descriptions are shown in the official language in which they were submitted.
2140168
Case EL-6828-A
DI8PERSANTB FOR LOBRICATING OIL
This invention relates to new and highly useful dis-
persants for use as additives to natural and synthetic lu-
bricating oils. More particularly this invention relates
to novel dispersant compositions that have reduced reacti-
vity toward fluoroelastomers coupled with effective disper-
sancy, especially for engine oils for either spark-ignition
passenger car service or heavy duty diesel engine service.
A continuing problem in the art of lubrication is to
provide lubricant compositions which satisfy the demands
imposed upon them by the original equipment manufacturers.
One such requirement is that the lubricant satisfy one or
more tests for fluoroelastomer degradation under specified
laboratory test conditions. The commercial reality is that
if the lubricant is unable to pass the applicable test or
tests, it is unlikely to meet acceptance in the market-
place. Standard test methods for evaluating fluoroelasto-
mer compatibility of lubricant compositions include the
Volkswagen PV 3334 Seal Test and the CCMC Viton Seal Test
(CEC L-39-T-87 Oil/Elastomer Compatibility Test).
More recently, a new, even more severe fluoroelastomer
test procedure has been developed, namely the Volkswagen PV
3344 Seal Test. This test is so severe that a variety of
commercially-available premium motor oils from various
manufacturers have been found to fail this test.
2140168
Thus, a need has arisen for a dispersant that exhibits
reduced antagonism toward fluoroelastomers in at least one
of the above standard test procedures. At the same time it
is important for the product to have sufficient effective-
ness as a dispersant to satisfy various requirements of
sludge, varnish and wear control.
This invention is deemed to fulfill the foregoing need
in an effective and efficient manner. The dispersant com-
positions of this invention are deemed to fulfill these re-
quirements as they exhibit little antagonism toward fluoro
elastomers and most if not all are capable of achieving pas
sing results in one or more of the foregoing test proce
dures. Moreover, the dispersants make possible highly ef
fective control of sludge, varnish and wear under various
types of engine service.
In accordance with this invention, there is provided
an oil-soluble dispersant composition which comprises:
a) an oil-soluble product formed by reacting aminoguani
dine with a long chain alkyl or alkenyl succinic acy
lating agent in a mole ratio of about 0.4 to about 1.3
moles (and preferably about 0.8 to about 1.3 moles) of
aminoguanidine and/or basic salt thereof per mole of
said acylating agent: and
b) an oil-soluble product formed by reacting (i) an acy
clic hydrocarbyl succinic acylating agent and (ii) an
alkylene polyamine having an average of about 3 to
about 6 nitrogen atoms (and preferably an average of
about 4 to about 5 nitrogen atoms) per molecule in a
mole ratio of about 1.6 to 2 (and preferably about 1.8
2
2140158
to 2) moles of (i) per mole of (ii) to form a succini-
mide and heating the succinimide so formed concurrent-
ly or in any sequence and at a temperature in the
range of about 150 to about 180°C with (iii) at least
one dicarboxylic acylating agent having less than 20
carbon atoms in the molecule, and (iv) at least one
boron compound to form a product having (1) a total
base number in the range of about 33 to about 45 mil-
ligrams of KOH per gram of said product (as active
ingredient, i.e., excluding the weight of solvent or
diluent, if any, that may be associated with said pro
duct), and (2) a boron content in the range of about
1.0 to about 1.4 wt% (again excluding the weight of
any solvent and/or diluent that may be associated with
said product):
wherein a) and b) are proportioned such that for every 0.7
to 1.8 part by weight of nitrogen (and preferably for every
0. 8 to 1. 7 part by weight of nitrogen) from a) , there is
about 0.3 to about 1.5 part by weight of nitrogen (and pre-
ferably about 0.4 to about 1.4 part by weight of nitrogen)
from b ) .
Another embodiment of this invention is a composition
which comprises from 1 to 99 wt% of at least one oil of
lubricating viscosity and from 99 to 1 wt% of a combination
of the above components a) and b), proportioned as above.
Still another embodiment is an additive concentrate
formulated for use as a crankcase lubricating oil additive
(also known as a DI-pack) which comprises the above compo-
nents a) and b), proportioned as above; c) at least one
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210168
oil-soluble metal dihydrocarbyl dithiophosphate (preferably
one or more zinc dialkyl dithiophosphate antiwear/extreme
pressure agents); d) at least one alkali or alkaline earth
metal-containing detergent (e. g., an alkali or alkaline
earth metal sulfonate, carboxylate, salicylate, or sulfur-
ized alkylphenate, or combination of two or more of such
detergents); and e) one or more inhibitors selected from
oxidation inhibitor(s), foam inhibitor(s), rust inhibi-
tor(s), corrosion inhibitors) and friction inhibitor(s):
wherein components a), b), c), d) and e) are proportioned
in the additive concentrate such that blending a minor
amount of the additive concentrate in a base oil (e.g., at
a concentration in the range of 3.2 to 16.1 wt% on an
active ingredient basis) provides an oil blend that con-
tams a dispersant amount of a) plus b) proportioned as
above, a wear-inhibiting amount of c), a detergent amount
of d), and an inhibiting amount of each said inhibitor se-
lected. On an active ingredient basis, a minor dispersing
amount of a) plus b) in the finished lubricating oil is
typically in the range of about 2 to about 5.5 wt% with the
proviso that the level of nitrogen from b) in the finished
lubricating oil does not exceed 0.042 wt%. Similarly, a
minor wear-inhibiting amount of c) in the finished
lubricating oil is typically in the range of about 0.5 to
about 1.25 wt%, and when the wear inhibitor is in the form
of a phosphorus-containing product, a minor wear-inhibiting
amount is typically equivalent to a phosphorus content in
the finished lubricating oil in the range of about 0.04 to
about 0.12 wt% of phosphorus. Likewise, a minor detergent
amount of d) in the finished lubricating oil is typically
in the range of about 0.5 to about 3.5 wt%, a minor
4
2140168
oxidation inhibiting amount of oxidation inhibitor in the
finished lubricating oil is typically in the range of about
0.2 to about 3 wt%, a minor foam inhibiting amount of foam
inhibitor in the finished lubricating oil is typically in
the range of about 0.0002 to about 0.001 wt%, a minor rust
inhibiting amount of rust inhibitor in the finished lubri-
cating oil is typically in the range of about 0.01 to about
0.4 wt%, a minor corrosion inhibiting amount of corrosion
inhibitor in the finished lubricating oil is typically in
the range of about 0.01 to about 0.4 wt%, and a minor fric-
tion inhibiting amount of friction inhibitor in the fi-
nished lubricating oil is typically in the range of about
0.02 to about 2 wt%. In each instance, the respective
components a), b), c), and d), and each of the selected
components of e) can be a single component or it can be a
mixture of two or more of the specified type of components.
A further embodiment provides a finished lubricating
oil composition which comprises a major amount of at least
one oil of lubricating viscosity; a minor dispersant amount
of a) plus b) proportioned as above; a minor wear-inhibit-
ing amount of c) : a minor detergent amount of d) ; and at
least one inhibitor of e), e.g., optionally, but prefera-
bly, a minor oxidation inhibiting amount of at least one
oxidation inhibitor: optionally, but preferably, a minor
foam inhibiting amount of foam inhibitor; optionally, a
minor friction inhibiting amount of friction inhibitor
optionally, a minor rust inhibiting amount of rust inhibi-
tor: and optionally, a minor corrosion inhibiting amount of
corrosion inhibitor. The finished lubricating oil composi-
tion preferably additionally contains a minor viscosity im-
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2140168
proving amount of at least one viscosity index improver.
Accordingly, this invention provides lubricant compositions
comprising oil of lubricating viscosity and one or more,
and preferably all, of the following components: viscosity
index improver, metal (most preferably zinc) dialkyl di-
thiophosphate, alkali or alkaline earth metal detergent
(preferably sulfonate, sulfurized phenate and/or salicy-
late), antioxidant (preferably phenolic, aromatic amine,
sulfurized olefin or copper-based), and antifoam agent
(preferably silicone-based). Other typical additive com-
ponents can also be present. For further details, see for
example U.S. Pat. No. 5,137,980.
Still another embodiment involves the use of compo-
nents a) and b), proportioned as above, in minor amount in
oil of lubricating viscosity to provide dispersancy and to
minimize degradation of fluoroelastomers that are in con-
tact with the oil either during additive qualification
tests or during use under actual service conditions.
In each and every one of the above described embodi-
ments, it is preferred, though not required, that component
a) thereof be a borated component, i.e., the product there-
of is heated with a boron compound or other suitable boron
source at a temperature high enough to form a product hav-
ing a boron content in the range of up to about 1 wt%, ex-
cluding the weight-of solvent and/or diluent, if any, that
may be associated with said product.
6
214016
These and other embodiments of this invention will be
still further apparent from the ensuing description and ap-
pended claims.
Base Oils. The base oils used in forming the lubri-
cant compositions of this invention can be natural or syn-
thetic oils of lubricating viscosity, or suitable blends
thereof. Thus the base oils can be hydrocarbon oils de-
rived from petroleum (or tar sands, coal, shale, etc.).
Likewise, the base oils can be or include natural oils of
suitable viscosities such as rapeseed oil, etc., and syn-
thetic oils such as hydrogenated polyolefin oils; poly-
a-olefins (e. g., hydrogenated or unhydrogenated a-olefin
oligomers such as hydrogenated poly-1-decene); alkyl esters
of dicarboxylic acids; complex esters of dicarboxylic acid,
polyglycol and alcohol; and the like. Mixtures of mineral,
natural and/or synthetic oils in any suitable proportions
are also useable.
In most cases the base oil is preferably a petroleum-
derived mineral oil of the type and viscosity suitable for
use in forming a passenger car engine oil, a heavy duty
diesel engine oil, or a drivetrain lubricant.
Component a). For convenience, the term "AG disper-
sant" is used to designate a product made by reacting ami-
noguanidine or a basic salt thereof with a hydrocarbyl-sub-
stituted succinic acid or anhydride in a mole ratio of from
about 0.4 to 1.3 moles of the aminoguanidine or basic salt
thereof per mole of the succinic acid or anhydride com-
pound. Likewise, the term "borated AG dispersant" is used
7
2140168
to designate a product made in two stages, namely, (i)
reacting aminoguanidine or a basic salt thereof with a hy-
drocarbyl-substituted succinic acid or anhydride in a mole
ratio of from about 0.4 to 1.3 moles of the aminoguanidine
or basic salt thereof per mole of the succinic acid or an-
hydride compound: and (ii) borating the product so pro-
duced.
To prepare the AG dispersant, a suitably proportioned
mixture of an aliphatic hydrocarbyl-substituted succinic
acid derivative (acid, anhydride, lower alkyl ester, or
acyl halide) and aminoguanidine or a basic salt thereof is
heated, preferably under an inert atmosphere, at a tempera-
ture in the range of about 80 to about 200°C, and prefera-
bly in the range of 140 to 200°C, with temperatures in the
range 160 to 170°C being most preferred. The reaction can
be conducted in the presence or absence of a solvent or
reaction diluent. When using alkenyl succinic acylating
agents in which the alkenyl substituent is derived from a
polyolefin of lower molecular weight (e. g., a GPC number
average molecular weight of 1300), it is preferred to con-
duct the acylation reaction in the absence of a reaction
diluent, and to add a diluent, such as a mineral oil to the
reaction product after it has been produced. On the other
hand, with alkenyl succinic acylating agents in which the
alkenyl substituent is derived from a polyolefin of some-
what higher molecular weight (e. g., a GPC number average
molecular weight of 2100), it is desirable to conduct the
reaction in a suitable diluent such as process oil or the
like. Reaction times are typically in the range of from 1
to 4 hours. Suitable inert atmospheres include nitrogen,
8
2140168
argon, krypton, neon, etc. As noted above, it is required
pursuant to this invention, to employ a product made using
from about 0.4 to 1.3 moles of aminoguanidine or basic salt
thereof per mole of the aliphatic hydrocarbyl-substituted
succinic acid derivative.
In order to prepare borated AG dispersant, AG disper-
sant formed as above is heated in combination with a suit-
able boron-containing material such that the resultant pro-
duct contains up to about 1% by weight of boron (excluding
the weight of any diluent or solvent that may be associated
with the product). Temperatures in the range of about 80
to about 200 ° C are generally satisfactory for use in the
boration reaction. Suitable methods for conducting bora-
tion are very well known to those skilled in the art. See
in the connection, U.S. Pat. Nos. 3,087,936; 3,254,025;
3,322,670; 3,344,069; 4,080,303: 4,426,305; 4,925,983 and
5,114,602.
AG dispersants are characterized by having an infrared
peak in the region of 1590 cm-~. Additionally, the spectrum
may exhibit a peak in the region of 1690 cm-~, but AG disper-
sants can be used that do not exhibit this latter peak.
When made at mole ratios of about 1:1 or lower, a peak at
1725 cm-~ appears. The 1590 cm-~ peak is nearly absent in
the Examples of U.S. Pat. No. 5,080,815. The chemical
structures of the products of this invention are unknown,
but on the basis of their infrared spectra, they do not
appear to have any significant content of triazole moie-
ties, as is shown by the absence of the 1640 cm-~ IR peak
present in the Examples of U.S. Pat. No. 5,080,815.
9
21~01~8
Methods are known for producing suitable aliphatic hy-
drocarbyl-substituted succinic acid derivatives (acid, an-
hydride, lower alkyl ester, or acyl halide), such as alken-
yl succinic anhydrides, to be used in reaction with amino-
guanidine or basic salts thereof. Such acylating agents
have been extensively described and discussed in the liter-
ature, for example U.S. Pat. Nos. 3,215,707; 3,219,666;
3,231,587: 3,254,025 3,282,955: 3,361,673; 3,401,118;
3,912,764; 4,110,349; 4,234,435; 4,908,145; 5,071,919:
5,080,815: and 5,137,978. In fact, suitable acylating
agents of this type are manufactured in large quantities
and are in widespread use in the manufacture of disper-
sants. Preferred acylating agents for use in forming
component a) are derived from a polyalkene having a number
average molecular weight as determined by GPC in the range
of 900 to 5000. Most preferably they have a number average
molecular weight in the range of 1200 to 2500. While homo
polymers and copolymers of a variety of 1-olefins can be
used for preparing the acylating agents, commercial grades
of polyisobutene are the preferred materials.
The synthesis of typical AG dispersants and borated AG
dispersants are set forth in the following examples.
ERAMPLE A-1
Into a reaction vessel are charged 1665 g (0.48 mole)
of 60% active polyisobutenyl succinic anhydride (PIBSA)
(formed from polyisobutylene having a number average mole
cular weight of about 2060), 76.8 g (0.56 mole) of 98.5%
aminoguanidine bicarbonate (AGB), and 600 g of a 100 neu
tral base oil. The mole ratio of AGB to PIBSA is 1.2:1.
2~~~iss
The mixture is heated at 170°C under a nitrogen sweep for
2 hours with stirring. The product is filtered while hot
and allowed to cool.
ERAMPLE A-2
The procedure of Example A-1 is repeated using a chemi-
cally equivalent amount of PIBSA produced using a polyisobu-
tylene having a number average molecular weight of about
1290 in lieu of the higher molecular weight PIBSA of Exam-
ple A-1.
ERAMPLE A-3
The procedure of Example A-1 is repeated except that
the AGB:PIBSA mole ratio is 1.1:1.
EgAMPLE A-4
Example A-3 is repeated except that the PIBSA of
Example A-2 is employed.
EBAMPLE A-5
Product formed as in Example A-3 is borated by heating
2290 g of the 44% active product so formed with 212.5 g of
a superborated polyisobutenyl succinic ester-amide contain-
ing approximately 2.5% of boron at 160°C for 2 hours. The
resultant product is diluted with 154 g oil to give a pro-
duct containing 0.2% boron.
EgAMPLE A-6
Example A-5 is repeated, but using 2000 g of product
formed as in Example A-4 and 185.6 g of the superborated
11
~~~o~s~
ester-amide. The boron content of the borated product is
0.2% on dilution with 134 g oil.
EXAMPLE A-7
Product formed as in Example A-1 (2290 g) is borated
by heating with 572.5 g of the superborated ester-amide and
diluted with oil to give a product with 0.5% boron.
EXAMPLE A-8
Example A-7 is repeated except that 2000 g of active
product formed as in Example A-2 is used instead of the
higher molecular weight product of Example A-1.
ERAMPLES A-9 to A-15
The procedure of Example A-1 is repeated seven times
in the same manner except that the proportions of AGB and
PIBSA are varied such that the respective AGB:PIBSA mole
ratios are 0.4:1, 0.5:1. 0.6:1, 0.7:1, 0.8:1, 0.9:1 and
1:1.
EXAMPLES A-16 to A-22
Examples A-9 to A-15 are repeated, but using product
formed as in Example A-2 in place of the product formed as
in Example A-1.
EXAMPLES A-23 to A-36
The respective products formed as in Examples A-9 to
A-22 are borated to boron levels of 0.2% using the boration
procedure of Example A-5.
12
21401fi8
EXAMPhE A-37
Example A-1 is repeated except that 1.0 mole of AGB is
reacted with 0.8 mole of PIBSA. Boration to a boron level
of 0.2% is carried out at a suitable temperature between
145 and 165°C using boric acid. Water is stripped off at
approximately 155°C and 40 mm Hg on completion of the bora-
tion.
Component b). This oil-soluble ashless dispersant is
obtained by reacting (i) an acyclic hydrocarbyl succinic
acylating agent and (ii) an alkylene polyamine having an
average of about 3 to about 6 nitrogen atoms (and prefera-
bly an average of about 4 to about 5 nitrogen atoms) per
molecule in a mole ratio of about 1.6 to 2 (and preferably
about 1. 8 to 2 ) moles of ( i) per mole of ( ii) to form a
succinimide and heating the succinimide so formed concur-
rently or in any sequence and at a temperature in the range
of about 150 to about 180°C with (iii) at least one dicar-
boxylic acylating agent having less than 20 carbon atoms in
the molecule, and (iv) at least one boron material to form
a product having (1) a total base number in the range of
about 33 to about 45 milligrams of KOH per gram of said
product (excluding the weight of any solvent and/or diluent
that may be associated with said product), and (2) a boron
content in the range of about 1.0 to about 1.4 wt% (again
excluding the weight of any solvent and/or diluent that may
be associated with said product).
Aliphatic hydrocarbyl-substituted succinic acid deri-
vatives (acid, anhydride, lower alkyl ester, or acyl ha-
lide), such as alkenyl succinic anhydrides, that are used
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2140168
as reactant (i) above are of the same general types as used
in forming component a). Thus for further details one
should refer to the description given hereinabove. It is
to be understood and appreciated however that the acylating
agents used in forming components a) and b) need not be
identical to each other. For example, the number average
molecular weights of polyolefins used in forming these
respective succinic acylating agents can be the same, or
they can differ from each other whereby the number average
molecular weight of either one of the polyolefins can be
higher than that of the other. Likewise the succinic acy-
lating agents used in forming components a) and b) can (and
preferably are) both anhydrides, although it is possible to
use different kinds of functionalized succinic acylating
agents in forming these respective components (e. g., using
an anhydride for forming one of the components, and a free
acid for forming the other).
Alkylene polyamines having an average of from about 3
to about 6 nitrogen atoms per molecule used as reactants
(ii) in forming component b) are generally referred to in
the art as dialkylene triamines, trialkylene tetramines,
tetraalkylene pentamines and pentaalkylene hexamines. The
alkylene groups of these materials can have from 2 to 4 or
more carbon atoms each. Preferred for use are the polyeth-
ylene polyamines, i.e., the polyalkylene polyamines in
which the alkylene groups are ethylene (i.e., dimethylene)
groups. The alkylene polyamines used in the synthesis of
component b) can be substantially pure compounds of the
specified structure (e. g., substantially pure tetraethylene
pentamine of the formula:
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2140168
HZN-C2H4-NH-CzH4-NH-CZH4-NH-CZH4-NH2 )
or they can be technical grade materials such as are avail-
able on the open market from a number of suppliers. These
technical grade products are often referred to for example
as diethylene triamine, triethylene tetramine, tetraethy-
lene pentamine and pentaethylene hexamine even though they
typically comprise linear, branched and cyclic species.
The dicarboxylic acylating agent having less than 20
carbon atoms in the molecule used as reactant (iii) in
post-treating the succinimide is preferably selected from
(a) acyclic dicarboxylic acids having up to 6 carbon atoms
in the molecule and wherein the carboxyl groups are attach-
ed to adjacent carbon atoms, (b) anhydrides of the said di-
carboxylic acids, (c) acyl halides of the said dicarboxylic
acids, and (d) acyclic mono- and/or dihydrocarbyl esters of
the said dicarboxylic acids having no more than 7 carbon
atoms per hydrocarbyl group. Examples of these acylating
agents include malefic acid, malefic anhydride, a-ethylmaleic
acid, malic acid, fumaric acid, itaconic acid, itaconic an-
hydride, citraconic acid, citraconic anhydride, succinic
acid, succinic anhydride, a-methylsuccinic acid, a,a-di-
methylsuccinic acid, a,p-dimethylsuccinic acid, a-ethyl-
succinic acid, thiomalic acid, tartaric acid, the monoalkyl
esters of the foregoing acids wherein the alkyl group has
from 1 to 7 carbon atoms, the dialkyl esters of the fore-
going acids wherein each alkyl group has from 1 to 7 carbon
atoms, the monoalkenyl esters of the foregoing acids where-
in the alkenyl group has from 2 to 7 carbon atoms, the di-
alkenyl esters of the foregoing acids wherein each alkenyl
group has from 2 to 7 carbon atoms, the acyl chlorides of
2140168
the foregoing acids, and the like. The most preferred
post-treating agent for use in the practice of this inven-
tion is malefic anhydride.
Reactant (iv) is a boron-containing material of the
same general type as can be used in borating component a)
in accordance with preferred embodiment thereof. Likewise
the temperature and other boration conditions used can be
the same or similar to those applicable for use in forming
a borated version of component a). Thus for further de-
tails reference should be had to the applicable discussion
hereinabove. It is to be understood and appreciated how-
ever that the borating agents and boration conditions used
in forming component b) and in forming a borated version of
component a) need not be identical to each other. Thus,
for example the borating agents can both be the same boron
acid, boron ester, boron halide, boron oxide, ammonium
borate, organoborane, or superborated ashless dispersant,
or conversely, the borating agent used in forming one of
the components can differ from that used in borating the
other. Likewise the times, temperatures and proportions of
ingredients used in the respective borations can be the
same or different from each other -- one component can be
borated to a higher level than the other.
Suitable procedures for producing component b) are
illustrated in the following examples.
ERAMPLE B-1
In a first stage reaction, polyisobutenylsuccinic
anhydride (PIBSA) formed from polyisobutylene having a GPC
16
21401~~
number average molecular weight of about 1300 and tetraeth-
ylene pentamine (TEPA) in a mole ratio of 1.8:1 are reacted
at 165-170°C for 4 hours. In a second stage reaction, ma-
lefic anhydride (MA) is added to the first stage reaction
product in amount equivalent to 0.35 mole per mole of TEPA
used in the first stage and the resultant mixture is heated
at 165-170°C for 1.5 hours after which oil is added. In a
third stage reaction, boric acid is added to the second
stage reaction mixture at a temperature of 150-155°C in an
amount corresponding to 4.0 moles per mole of TEPA initial-
ly employed. The mixture is heated at 150°C for one hour
and then water formed in the third stage reaction is re-
moved by applying a vacuum of 40 mm for one hour. The
resulting succinimide is both acylated and boronated and
has a nitrogen content of 1.74%, and a boron content of
1.20%.
EBAMPLE B-2
The procedure of Example B-1 is repeated except that
the amount of boric acid is reduced to 3.0 moles per mole
of TEPA initially used. The final product, diluted to
1.70% nitrogen content with 100 solvent neutral mineral oil
contains 0.82% boron.
EXAMPLE B-3
Repetition of Example B-1 wherein the amount of boric
acid is still further reduced to 2.0 moles per mole of TEPA
initially used yields a concentrate (diluted as in Example
B-1) having a boron content of 0.62%.
17
~i4o~sg
EXAMPLE B-4
Example B-1 is repeated but using 3.25 moles of boric
acid per mole of TEPA initially used. The product concen-
trate (diluted as in Example B-1) contains 0.88% boron.
EXAMPLE B-5
The procedure of Example B-1 is repeated except that
the reaction with boric acid is conducted before the reac-
tion with malefic anhydride and the amount of boric acid
used corresponds to 3.0 moles per mole of TEPA used in the
first stage reaction. The final product (diluted as in
Example B-1) contains 0.9% boron.
EXAMPLE B-6
Example 5 is repeated except that the malefic anhydride
and the boric acid are concurrently reacted with the succi
nimide formed in the first stage reaction. One such pro
duct on dilution with 100 solvent neutral mineral oil con-
tained 1.66% nitrogen and 0.87% boron.
ERAMPLE B-7
In the first stage reaction, polyisobutenylsuccinic
anhydride (PIBSA) formed from polyisobutylene with a GPC
number average molecular weight of about 1300 and tetraeth
ylene pentamine (TEPA) in a mole ratio of 1.8:1 are reacted
at 165-170°C for 4 hours and then mineral oil added. In a
second stage reaction, malefic anhydride (MA) is added to
the first stage reaction product in an amount equivalent to
0.3 moles per mole of TEPA used in the first stage and the
resultant mixture is heated at 165-170°C for 1-1/2 hours.
In a third stage reaction, boric acid (BA) is added to the
18
2140~fi8
second stage reaction product in an amount equivalent to
3.0 moles per mole of TEPA used in the first stage and the
resultant mixture is heated at 150-155°C for 2-1/2 hours.
The additive concentrate has a nitrogen content of 1.8% and
a boron content of 0.9%.
EBAMPLE B-8
The procedure of Example B-7 is repeated except that
in the first stage the PIBSA and TEPA are reacted in a mo-
lar ratio of 1.7:1. In the second stage the MA is used in
amount equivalent to a mole ratio of 0.4:1 relative to the
TEPA used in the first stage. In the third stage, the bor-
ic acid (3.0 moles per mole of TEPA used in the first stage
reaction) is added in an oil slurry. The product on dilu-
tion has a nitrogen content of 1.95% and a boron content of
0.64%.
EgAMPLE B-9
In the first stage reaction, polyisobutenylsuccinic
anhydride having a GPC number average molecular weight of
about 1200 and TEPA are reacted in a mole ratio of 1.8:1.
In a second stage, malefic anhydride is added to the first
stage reaction product in an amount equivalent to 0.35 mole
per mole of TEPA used in the first stage and the resultant
mixture is heated at 165-170°C for 1-1/2 hours after which
mineral oil is added. In a third stage reaction, boric
acid is added to the second stage reaction product in an
amount equivalent to 0.4 mole per mole of TEPA used in the
first stage and the resultant mixture is heated at 150 to
155°C for 3 hours. The product has a nitrogen content of
1.85% and a boron content of 0.15%.
19
~m~~s~
Component c). Metal hydrocarbyl dithiophosphates are
usually prepared by reacting phosphorus pentasulfide with
one or more alcohols or phenolic compounds or diols to pro-
duce a hydrocarbyl dithiophosphoric acid which is then neu-
tralized with one or more metal-containing bases. When a
monohydric alcohol or phenol is used in this reaction, the
final product is a zinc dihydrocarbyl dithiophosphate. On
the other hand, when a suitable diol (e. g., 2,4-pentanedi-
ol) is used in this reaction, the final product is a zinc
salt of a cyclic hydrocarbyl dithiophosphoric acid. See,
for example, U.S. Pat. No. 3,089,850. These cyclic deriva-
tives function in essentially the same way as the dihydro-
carbyl analogs.
Suitable oil-soluble metal dihydrocarbyl dithiophos-
phates include molybdenum dihydrocarbyl dithiophosphates,
nickel dihydrocarbyl dithiophosphates, copper dihydrocarbyl
dithiophosphates, cadmium dihydrocarbyl dithiophosphates,
cobalt dihydrocarbyl dithiophosphates, and similar materi-
als. The hydrocarbyl groups include cyclic and acyclic
groups, both saturated and unsaturated, such as alkyl,
cycloalkyl, alkenyl, cycloalkenyl, aryl, cycloalkylalkyl,
aralkyl, and the like. It will be understood that the hy-
drocarbyl groups may contain elements other than carbon and
hydrogen provided such other elements do not detract from
the predominantly hydrocarbonaceous character of the hydro-
carbyl group. Thus the hydrocarbyl groups may contain
ether oxygen atoms, thioether sulfur atoms, secondary or
tertiary amino nitrogen atoms, and/or inert functional
groups such as esterified carboxylic groups, keto groups,
thioketo groups, and the like. The preferred materials are
21~01~8
the oil-soluble zinc dihydrocarbyl dithiophosphates, espe-
cially the oil-soluble zinc dialkyl dithiophosphates, and
most especially oil-soluble zinc dialkyl dithiophosphates
in which the alkyl groups are a mixture of primary and
secondary alkyl groups. Such primary and secondary alkyl
group mixtures can be formed by forming a mixture of two or
more zinc dialkyldithiophosphates that results in a mixture
or combination of zinc dialkyl dithiophosphates having the
desired types and proportions of primary and secondary al-
kyl groups. Alternatively, the primary and secondary alkyl
group mixtures can be formed by reacting phosphorus penta
sulfide with a mixture or combination of primary and secon
dary alcohols that yields a zinc dialkyl dithiophosphate
product having the desired types and proportions of primary
and secondary alkyl groups.
The phosphorodithioic acids from which the metal salts
are formed can be prepared by the reaction of about 4 moles
of one or more alcohols (cyclic or acyclic) or one or more
phenols or mixture of one or more alcohols and one or more
phenols (or about 2 moles of one or more diols) per mole of
phosphorus pentasulfide, and the reaction may be carried
out within a temperature range of from about 50 to about
200°C. The reaction generally is completed in about 1 to
10 hours. Hydrogen sulfide is liberated during the reac
tion.
The alcohols used in forming the phosphorodithioic
acids by the above method are preferably primary alcohols,
or secondary alcohols. Mixtures thereof are also suitable.
The primary alcohols include propanol, butanol, isobutyl al-
21
2140i~'8
cohol, pentanol, 2-ethyl-1-hexanol, isooctyl alcohol, no-
nanol, decanol, undecanol, dodecanol, tridecanol, tetradec-
anol, octadecanol, eicosanol, and the like. The primary
alcohols may contain various substituent groups such as
halogen atoms, nitro groups, etc., which do not interfere
with the desired reaction. Among suitable secondary alco-
hols are included 2-butanol, 2-pentanol, 3-pentanol, 2-
hexanol, 4-methyl-2-pentanol, 5-methyl-2-hexanol, and the
like. In some cases, it is preferable to utilize mixtures
of various alcohols, such as mixtures of 2-propanol with
one or more higher molecular weight primary alcohols,
especially primary alcohols having from 4 to about 13
carbon atoms in the molecule. Such mixtures preferably
contain at least 10 mole percent of 2-propanol, and usually
will contain from about 20 to about 90 mole percent of 2-
propanol. In one specific embodiment, the alcohol
comprises about 30 to 50 mole percent of 2-propanol, about
30 to 50 mole percent isobutyl alcohol and about 10 to 30
mole percent of 2-ethyl-1-hexanol.
Other suitable mixtures of alcohols include 2-propan-
ol/butanol;2-propanol/2-butanol;2-propanol/2-ethyl-1-hex-
anol; butanol/2-ethyl-1-hexanol; isobutyl alcohol/2-ethyl-
1-hexanol; and 2-propanol/tridecanol.
Cycloaliphatic alcohols suitable for use in the pro-
duction of the phosphorodithioic acids include cyclopenta-
nol, cyclohexanol, methylcyclohexanol, cyclooctanol, borne-
ol and the like. Preferably, such alcohols are used in com-
bination with one or more primary alkanols such as butanol,
isobutyl alcohol, or the like.
22
21~010~
Illustrative phenols which can be employed in forming
the phosphorodithioic acids include phenol, o-cresol, m-
cresol, p-cresol, 4-ethylphenol, 2,4-xylenol, and the like.
It is desirable to employ phenolic compounds in combination
with primary alkanols such propanol, butanol, hexanol, or
the like.
Other alcohols which can be employed include benzyl
alcohol, cyclohexenol, and their ring-alkylated analogs.
It will be appreciated that when mixtures of two or
more alcohols and/or phenols are employed in forming the
phosphorodithioic acid, the resultant product will normally
comprise a mixture of three or more different dihydrocarbyl
phosphorodithioic acids, usually in the form of a statisti
cal distribution in relation to the number and proportions
of alcohols and/or phenols used.
Illustrative diols which can be used in forming the
phosphorodithioic acids include 2,4-pentanediol, 2,4-hex
anediol, 3,5-heptanediol, 7-methyl-2,4-octanediol, neopent
yl glycol, 2-butyl-1,3-propanediol, 2,2-diethyl-1,3-pro
panediol, and the like.
The preparation of the zinc salts of the dihydrocarbyl
dithiophosphoric acids or the cyclic hydrocarbyl dithiophos-
phoric acids is usually effected by reacting the acid pro-
duct with a suitable zinc compound such as zinc oxide, zinc
carbonate, zinc hydroxide, zinc alkoxide, or other appro-
priate zinc salt. Simply mixing and heating such reactants
is normally sufficient to cause the reaction to occur and
23
2~44~6
the resulting product is usually of sufficient purity for
use. Typically, the salts are formed in the presence of a
diluent such as an alcohol, water or a light mineral oil.
Neutral salts are prepared by reacting one equivalent of
the zinc oxide or hydroxide with one equivalent of the
acid. Basic zinc salts are prepared by adding an excess
(i.e., more than one equivalent) of the zinc oxide or
hydroxide with one equivalent of the dihydrocarbyl phos
phorodithioic acid or cyclic hydrocarbyl phosphorodithioic
acid.
In some cases, incorporation of certain ingredients
such as small amounts of zinc acetate or acetic acid in
conjunction with the zinc reactant will facilitate the re-
action and provide an improved product. For example, use
of up to about 5% of zinc acetate in combination with the
required amount of zinc oxide tends to facilitate the for-
mation of zinc dihydrocarbyl dithiophosphates.
Examples of useful zinc salts of dihydrocarbyl dithio-
phosphoric acids, and methods for preparing such salts are
found in the prior art such as for example, U.S. Pat. Nos.
4,263,150; 4,289,635: 4,308,154; 4,322,479; 4,417,990; and
4,466,895.
The preferred zinc salts of dialkyl dithiophosphoric
acids generally contain alkyl groups having at least three
carbon atoms each, and preferably the alkyl groups contain
up to 10 carbon atoms although as noted above, even higher
molecular weight alkyl groups are entirely feasible. A few
illustrative zinc dialkyl dithiophosphates include zinc di-
24
2140108
isopropyl dithiophosphate, zinc dibutyl dithiophosphate,
zinc diisobutyl dithiophosphate, zinc di-sec-butyl dithio-
phosphate, the zinc dipentyl dithiophosphates, the zinc di-
hexyl dithiophosphates, the zinc diheptyl dithiophosphates,
the zinc dioctyl dithiophosphates, the zinc dinonyl dithio-
phosphates, the zinc didecyl dithiophosphates, and the
higher homologs thereof. Mixtures of two or more such zinc
compounds are often preferred for use, such as zinc salts
of dithiophosphoric acids formed from mixtures of isopropyl
alcohol and secondary butyl alcohol; isopropyl alcohol,
isobutyl alcohol, and 2-ethylhexyl alcohol; isopropyl alco-
hol, butyl alcohol, and pentyl alcohol; isobutyl alcohol
and octyl alcohol; and the like.
The metal dihydrocarbyldithiophosphates may be pro
ducts that have been post-treated with such compounds as
carboxylic acids or epoxides.
Component d). In general, the metal-containing
detergents which can be employed are oil-soluble or oil-
dispersible basic salts of alkali or alkaline earth metals
with one or more of the following acidic substances (or
mixtures thereof): (1) sulfonic acids, (2) carboxylic
acids, (3) salicylic acids, (4) alkylphenols, (5) sulfu-
rized alkylphenols, (6) organic phosphorus acids charac-
terized by at least one direct carbon-to-phosphorus link-
age. Such organic phosphorus acids include those prepared
by the treatment of an olefin polymer (e. g., polyisobutene
having a molecular weight of 1000) with a phosphorizing
agent such as phosphorus trichloride, phosphorus hepta-
sulfide, phosphorus pentasulfide, phosphorus trichloride
2140168
and sulfur, white phosphorus and a sulfur halide, or phos-
phorothioic chloride. The most commonly used salts of such
acids are those of sodium, potassium, lithium, calcium,
magnesium, strontium and barium. The salts can be low-base
materials or overbased materials or combinations thereof.
Preferably at least a portion of component d) is an over
based metal detergent with a total base number (TBN) of at
least 200, and more preferably in the range of about 250 to
about 500. In this connection, TBN is determined in accor
dance with ASTM D-2896-88.
The term "basic salt" is used to designate metal salts
wherein the metal is present in stoichiometrically larger
amounts than the organic acid radical. The usual methods
for preparing the basic salts involve heating a mineral oil
solution of an acid with a stoichiometric excess of a metal
neutralizing agent such as the metal oxide, hydroxide, car-
bonate, bicarbonate, or sulfide at a temperature of at
least about 50°C, and filtering the resulting mass. Use in
the neutralization step of a "promoter" to aid the incorpo-
ration of a large excess of metal likewise is desirable.
Examples of compounds useful as the promoter include pheno-
lic substances such as phenol, naphthol, alkylphenol, thio-
phenol, sulfurized alkylphenol, and condensation products
of formaldehyde with a phenolic substance; alcohols such as
methanol, 2-propanol, octyl alcohol, 2-ethoxyethanol, 2-
ethoxy(2-ethoxyethanol), ethylene glycol, stearyl alcohol,
and cyclohexyl alcohol; and amines such as aniline, phen-
ylenediamine, phenothiazine, phenyl-~-naphthylamine, and
dodecylamine. A particularly effective method for prepar-
ing the basic salts comprises mixing an acid with an excess
26
21401~~
of a basic alkaline earth metal neutralizing agent and at
least one alcohol promoter, and carbonating the mixture at
an elevated temperature such as 60° to 200°C.
Examples of suitable metal-containing detergents in-
s clude, but are not limited to, the basic or overbased salts
of such substances as lithium phenates, sodium phenates,
potassium phenates, calcium phenates, magnesium phenates,
sulfurized lithium phenates, sulfurized sodium phenates,
sulfurized potassium phenates, sulfurized calcium phenates,
and sulfurized magnesium phenates wherein each aromatic
group has one or more aliphatic groups to impart hydrocar-
bon solubility: lithium sulfonates, sodium sulfonates, po-
tassium sulfonates, calcium sulfonates, and magnesium sul-
fonates wherein each sulfonic acid moiety is attached to an
aromatic nucleus which in turn usually contains one or more
aliphatic substituents to impart hydrocarbon solubility;
lithium salicylates, sodium salicylates, potassium sali-
cylates, calcium salicylates, and magnesium salicylates
wherein the aromatic moiety is usually substituted by one
or more aliphatic substituents to impart hydrocarbon solu-
bility; the lithium, sodium, potassium, calcium and magne-
sium salts of hydrolyzed phosphosulfurized olefins having
10 to 2,000 carbon atoms or of hydrolyzed phosphosulfurized
alcohols and/or aliphatic-substituted phenolic compounds
having 10 to 2,000 carbon atoms; lithium, sodium, potas-
sium, calcium and magnesium salts of aliphatic carboxylic
acids and aliphatic-substituted cycloaliphatic carboxylic
acids: and other similar alkali and alkaline earth metal
salts of oil-soluble organic acids. Mixtures of basic or
overbased salts of two or more different alkali and/or
27
214~16~
alkaline earth metals can be used. Likewise, basic or
overbased salts of mixtures of two or more different acids
or two or more different types of acids (e. g., one or more
calcium phenates with one or more calcium sulfonates) can
also be used.
As is well known, overbased metal detergents are gene-
rally regarded as containing overbasing quantities of inor-
ganic bases, probably in the form of micro dispersions or
colloidal suspensions. Thus the terms "oil-soluble" and
"oil-dispersible" are applied to these metal-containing de-
tergents so as to include metal detergents wherein inorgan-
ic bases are present that are not necessarily completely or
truly oil-soluble in the strict sense of the term, inasmuch
as such detergents when mixed into base oils behave in much
the same way as if they were fully and totally dissolved in
the oil.
Collectively, the various basic or overbased deter
gents referred to hereinabove, have sometimes been called,
quite simply, basic alkali metal or alkaline earth metal
containing organic acid salts.
Methods for the production of oil-soluble basic and
overbased alkali and alkaline earth metal-containing deter-
gents are known and are extensively reported in the patent
literature. See for example, the disclosures of U.S. Pat.
Nos. 2,451,345; 2,451,346; 2,485,861; 2,501,731; 2,501,732;
2,585,520; 2,671,758; 2,616,904: 2,616,905; 2,616,906;
2,616,911; 2,616,924; 2,616,925; 2,617,049; 2,695,910;
3,178,368; 3,367,867; 3,496,105; 3,629,109; 3,865,737;
28
214018
3,907,691: 4,100,085: 4,129,589: 4,137,184; 4,148,740;
4,212,752; 4,617,135: 4,647,387: and 4,880,550.
Component e). The inhibitors which can be used in the
practice of this invention include one or more oxidation in-
s hibitors, foam inhibitors, rust inhibitors, corrosion
inhibitors and friction inhibitors.
Oxidation inhibitors suitable for use in the composi-
tions of this invention include hindered phenolic antioxi-
dants, secondary aromatic amine antioxidants, sulfurized
phenolic antioxidants, sulfurized olefin antioxidants, oil-
soluble copper compounds, phosphorus-containing antioxi-
dants, and the like. Mixtures of two or more of these re-
spective types of antioxidants can be used.
Illustrative sterically hindered phenolic antioxidants
include ortho-alkylated phenolic compounds such as 2,6-di-
tert-butylphenol, 4-methyl-2,6-di-tert-butylphenol, 2,4,6-
tri-tert-butylphenol, 2-tert-butylphenol, 2,6-diisopropyl-
phenol, 2-methyl-6-tert-butylphenol, 2,4-dimethyl-6-tert-
butylphenol,4-(N,N-dimethylaminomethyl)-2,6-di-tert-butyl-
phenol,4-ethyl-2,6-di-tert-butylphenol,2-methyl-6-styryl-
phenol, 2,6-di-styryl-4-nonylphenol, and their analogs and
homologs. Mixtures of two or more such phenolic compounds
are also suitable.
Also useful are methylene-bridged alkylphenols, and
these can be used singly or alternatively, in combinations
with each other, or in combinations with sterically-hinder-
ed unbridged phenolic compounds. Illustrative methylene
29
CA 02140168 2003-11-21
bridged compounds include 4,4'-methylenebis(6-tert-butyl-
o-cresol), 4,4'-methylenebis(2-tert-amyl-o-cresol), 2,2'-
methylenebis(4-methyl-6-tert-butylphenol), 4,4'-methylene-
bis(2,6-di-tert-butylphenol), and similar compounds. Pre-
ferred mixtures of methylene-bridged alkylphenols are des-
cribed in U.S. Pat. No. 3,211,652.
Amine antioxidants, especially oil-soluble aromatic
secondary amines can also be used. Although aromatic se-
condary monoamines are preferred, aromatic secondary poly-
amines are also suitable. Illustrative aromatic secondary
monoamines include diphenylamine, ring-alkylated diphenyl-
amines containing 1 or more alkyl ring-substituents each
having up to about 16 carbon atoms, phenyl-a-naphthylamine,
phenyl-Q-naphthylamine, alkyl- or aralkyl-substituted phen-
yl-a-naphthylamine containing one or two alkyl or aralkyl
groups each having up to about 16 carbon atoms, alkyl- or
aralkyl-substituted phenyl-Q-naphthylamine containing one
or two alkyl or aralkyl groups each having up to about 16
carbon atoms, and similar compounds.
A preferred type of aromatic amine antioxidant is an
alkylated diphenylamine wherein one or both rings are sub-
stituted by an alkyl group (preferably a branched alkyl
group) having 8 to 12 carbon atoms, and more preferably 8
or 9 carbon atoms. One such preferred compound is avail-
able commercially as Naugalube'~' 438L, a material which is
understood to be predominately a 4,4'-dinonyldiphenylamine
wherein the nonyl groups are branched.
2140168
Another useful type of oxidation inhibitor for inclu-
sion in the compositions of this invention is one or more
oil-soluble sulfurized phenolic compounds. Oil-soluble su-
lfurized linear alpha-olefins are also highly satisfactory
oxidation inhibitors. Copper compounds when used in small
controlled concentrations, all as described in U.S. Pat.
No. 4,867,890, are also suitable.
Mixtures of different antioxidants can also be used.
One suitable mixture is comprised of a combination of (i)
an oil-soluble mixture of at least three different steric-
ally-hindered tertiary butylated monohydric phenols which
is in the liquid state at 25°C, (ii) an oil-soluble mixture
of at least three different sterically-hindered tertiary
butylated methylene-bridged polyphenols, and (iii) at least
one ring-alkylated di(phenyl)amine wherein each alkyl group
is a branched alkyl group having 8 to 12 carbon atoms, the
proportions of (i), (ii) and (iii) on a weight basis fal
ling in the range of 3.5 to 5.0 parts of component (i) and
0.9 to 1.2 parts of component (ii) per part by weight of
component (iii).
Suitable foam inhibitors are described in Foam Control
Agents by H. T. Kerner (Noyes Data Corporation, 1976, pages
125-176). Typical foam inhibitors include silicones and
organic polymers such as acrylate polymers. Mixtures of
silicone-type antifoam agents such as the liquid dialkyl
silicone polymers with various other substances are also
effective. Typical of such mixtures are silicones mixed
with an acrylate polymer, silicones mixed with one or more
amines, and silicones mixed with one or more amine carboxy-
31
21401~~
lates. Other such mixtures include combinations of a di-
methyl silicone oil with (i) a partial fatty acid ester of
a polyhydric alcohol (U.S. Pat. No. 3,235,498); (ii) an
alkoxylated partial fatty acid ester of a polyhydric alco-
hol (U. S. Pat. No. 3,235,499); (iii) a polyalkoxylated ali-
phatic amine (U. S. Pat. No. 3,235,501); and (iv) an alkox-
ylated aliphatic acid (U. S. Pat. No. 3,235,502). Also use-
ful are the metal salts of styrene-malefic anhydride copoly-
mers (U. S. Pat. No. 3,296,131).
Rust inhibitors that can be used may be a single
compound or a mixture of compounds having the property of
inhibiting corrosion of ferrous metal surfaces. Such
materials include oil-soluble monocarboxylic acids such as
2-ethylhexanoic acid, lauric acid, myristic acid, palmitic
acid, oleic acid, linoleic acid, linolenic acid, behenic
acid, cerotic acid, etc., and oil-soluble polycarboxylic
acids including dimer and trimer acids, such as are pro-
duced from tall oil fatty acids, oleic acid, linoleic acid,
or the like. Other suitable corrosion inhibitors include
alkenylsuccinic acids in which the alkenyl group contains
10 or more carbon atoms such as, for example, tetrapropen-
ylsuccinic acid, tetradecenylsuccinic acid, hexadecenylsuc-
cinic acid, and the like; long-chain a,?~-dicarboxylic acids
in the molecular weight range of 600 to 3000; and other
similar materials. Products of this type are currently
available from various commercial sources, such as, for
example, dimer and trimer acids. Another useful type of
acidic corrosion inhibitors are the half esters of alkenyl
succinic acids having 8 to 24 carbon atoms in the alkenyl
group with alcohols such as the polyglycols. The corre-
32
~140~~~
sponding half amides of such alkenyl succinic acids are
also useful. Other suitable corrosion inhibitors include
ether amines; acid phosphates: amines; polyethoxylated
compounds such as ethoxylated amines, ethoxylated phenols,
and ethoxylated alcohols: imidazolines: and the like.
Among the suitable corrosion inhibitors are the thi-
azoles, triazoles and thiadiazoles. Examples include ben-
zotriazole, tolyltriazole,octyltriazole, decyltriazole, do-
decyltriazole, 2-mercaptobenzothiazole, 2,5-dimercapto-
1,3,4-thiadiazole, 2-mercapto-5-hydrocarbylthio-1,3,4-thi-
adiazoles, 2-mercapto-5-hydrocarbyldithio-1,3,4-thiadia-
zoles, 2,5-bis(hydrocarbylthio)-1,3,4-thiadiazoles, and
2,5-bis(hydrocarbyldithio)-1,3,4-thiadiazoles. The prefer-
red compounds are the 1,3,4-thiadiazoles, especially the 2-
hydrocarbyldithio-5-mercapto-1,3,4-dithiadiazoles and the
2,5-bis(hydrocarbyldithio)-1,3,4-thiadiazoles, a number of
which are available as articles of commerce. Such products
are generally synthesized from hydrazine and carbon disul-
fide by known procedures. See for example U.S. Pat. Nos.
2,749,311; 2,760,933; 2,765,289; 2,850,453; 2,910,439;
3,663,561; 3,862,798; 3,840,549; and 4,097,387. Other
suitable corrosion inhibitors include ether amines; poly
ethoxylated compounds such as ethoxylated amines, ethoxy
lated phenols, and ethoxylated alcohols; imidazolines; and
the like.
Friction inhibitors which can be used include such
substances as the alkyl phosphonates as disclosed in U.S.
Pat. No. 4,356,097, aliphatic hydrocarbyl-substituted suc-
cinimides derived from ammonia or alkyl monoamines as dis-
33
2~~0~68
closed in European Patent Publication No. 20037, dimer acid
esters as disclosed in U.S. Pat. 4,105,571, oleamide, sul-
furized linear olefins, and the like. Glycerol oleates
such as glycerol monooleate, glycerol dioleate and penta-
erythritol monooleate are further examples of suitable
friction inhibitors which can be used to control friction
and improve fuel economy.
Other suitable friction modifiers include aliphatic
amines or ethoxylated aliphatic amines, aliphatic fatty
acid amides, aliphatic carboxylic acids, aliphatic carbox
ylic esters, aliphatic carboxylic ester-amides, aliphatic
phosphates, aliphatic thiophosphonates, aliphatic thiophos
phates, etc., wherein the aliphatic group usually contains
above about eight carbon atoms so as to render the compound
suitably oil soluble.
A desirable friction modifier additive combination
which may be used in the practice of this invention is de
scribed in European Patent Publication No. 389,237. This
combination involves use of a long chain succinimide deri
vative and a long chain amide.
Still other suitable additives can be included if
desired.
The practice and advantages of this invention will
become still further apparent from the following illustra-
tive examples. It is to be understood that these examples
do not constitute, are not intended to constitute, and
should not be construed as constituting, limitations on the
34
CA 02140168 2003-11-21
generic aspects of this invention. In these examples, all
percentages are by weight, and are on an active ingredient
basis.
EgAMPLE I
A 10W-40 finished lubricant of this invention is
formed from the following components:
Component Percentage
a) 3.17
b) 1.09
c) 1.06
d) 2.67
e) 1.40
Base oil, VI Improver, Diluent Oils Balance to 100%
Component a) is formed as in Example A-5 and component b)
as in Example B-4. Component c) is a mixture of zinc di-
alkyldithiophosphates of which 50% are C3 and C6 secondary
alkyl groups and 50% are C3, C4 and C8 primary and secondary
alkyl groups. Component d) is a mixture of 1.32% overbased
calcium sulfonate, 0.7% low-base calcium sulfonate, and
0.65% sulfurized alkylphenate. Component e) is a mixture
of 0.8% tertiary butylated phenolic antioxidant, 0.2%
aromatic amine antioxidant, 0.4% sulfurized olefin
oxidation inhibitor, and less than 0.001% of silicone type
foam inhibitor. Commercial materials used in forming this
component mixture include HITEC~ 611, 1656, 4733, 7169, and
7304 additives (Ethyl Petroleum Additives, Ltd.; Ethyl
Petroleum Additives, Inc.): OLOA~' 216C additive (Chevron
Chemical Company); and Naugalube 438L additive (Uniroyal
CA 02140168 2003-11-21
Chemical Company). The viscosity index improver is of the
OCP type (Paratone'~' 8000; Exxon Chemical Company). The
finished lubricant has a total base number (TBN) of 10 mg
of KOH per gram using the ASTM D2896 procedure, a zinc
content of 0.12%, a phosphorus content of 0.11% a calcium
content of 0.35% and a boron content of 0.02%.
EgAMPLE II
A 10W-40 lubricant of this invention is formed from
the following components:
Component Percentage
a) 3.11
b) 1.10
c) 0.94
d) 2.36
e) 1.50
Base oil, VI Improver, Diluent Oils Balance to 100%
Component a) is formed as in Example A-37 and component b)
as in Example B-4. Component c) is a mixture of C3 and C6
zinc dialkyldithiophosphates. Component d) is a mixture of
1.18% overbased calcium sulfonate, 0.85% low-base calcium
sulfonate, and 0.33% sulfurized alkylphenate. Component e)
is a mixture of 1.0% tertiary butylated phenolic antioxi-
dant, 0.5% aromatic amine antioxidant, and less than 0.001%
of silicone type foam inhibitor.
36
~i~~~s~
EXAMPLE III
A finished lubricant of this invention is produced
from the same components as in Example I but using the
following proportions:
~ Component ~ Percentage
a) 2.97
b) 1.37
c) 1.06
d) 2.67
e) 1.40
Base oil, VI Improver, Diluent Oils Balance to 100%
EXAMPLE IV
A lubricating oil composition of this invention is
produced using components a) and b) as in Example II, a 400
TBN overbased magnesium alkylbenzene sulfonate as component
d), and components c) and e) as in Example I in the propor-
tions given in the following table:
Component Percentage
a) 3.11
b) 1.10
c) 1.06
d) 2.28
e) 1.40
Base oil, VI Improver, Diluent Oils Balance to 100%
The performance of the compositions of this invention
is illustrated by the results of the MWM KD 12E engine test
37
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which measures performance of heavy duty diesel engine lu-
bricants under controlled conditions. Performance is ex-
pressed in terms of a numerical scale in which the higher
the numerical value, the better the performance. In two
such tests a lubricant of this invention and a comparable
lubricant not of this invention were used. Both contained
in addition to dispersant, a mixture of primary and
secondary alkyl zinc dialkyl dithiophosphates, a mixture of
high-base and low-base calcium sulfonates and a calcium
sulfurized alkyl phenate in substantially the same relative
proportions. The principal difference between these two
lubricants is that the dispersant of the lubricant not of
this invention consisted solely of a higher dosage level of
component a). Both lubricants were formulated to 10W-40
specification grade and had a TBN of 10 mg of KOH per gram
and an ash level of 1.42%. The lubricant of this invention
gave a rating of 80.6 as compared to a rating of 70.9 for
the lubricant not of this invention.
In tests conducted in similar fashion using the Volks-
wagen Intercooled (PV 1431) Test, a typical composition of
this invention formed as in Example II was found to give
significantly better piston cleanliness than a comparable
lubricant composition not of this invention. In both cases
the diesel engine was operated on a diesel fuel with a
sulfur content of 0.3%.
In the standard OM 364A test, a 10W-40 lubricant of
this invention exhibited excellent dispersancy and varnish
control performance, as well as good wear performance.
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CA 02140168 2003-11-21
The excellent fluoroelastomer seal performance made
possible by this invention is illustrated by the results of
tests conducted using the stringent Volkswagen PV 3344 test
procedure. In one set of tests VITOIV'~" AK6 fluoroelastomer
and the SAE 10W-40 heavy duty crankcase lubricant of Exam-
ple I were used. Table I summarizes the results.
Table I - Fluoroelastomer Compatibility Test Results
f Property j Results ~ Test Specifications
Tensile strength 9.5 MPa 8.0 Minimum
Elongation 188% 160% Minimum
Hardness 72 Report only
Cracking No cracking No cracking
A duplicate set of tests was carried out using the
same test procedure and fluoroelastomer, but using a compo-
sition formed as in Example III. The results are summa-
rized in Tables II and III.
Table II - Fluoroelastomer Compatibility Test Results
Property Results Test Specifications
Tensile strength 9.5 MPa 8.0 Minimum
Elongation 188% 160% Minimum
Hardness 72 Report only
Cracking No cracking No cracking
39
CA 02140168 2003-11-21
Table III - Fluoroelastomer Compatibility Test Results
Property Results Test Specifications
Tensile strength 8.5 MPa 8.0 Minimum
Elongation 181% 160% Minimum
Hardness 70 Report only
Cracking No cracking No cracking
It will be seen from Tables I, II and III that in
these tests the lubricant compositions of this invention
passed all requirements of the severe Volkswagen PV 3344
test procedure and in so doing, gave excellent results.
Similar excellent results have been achieved with other
compositions of this invention.
As used herein, the term "oil-soluble" means that the
product under discussion can be dissolved or stably dis-
persed in a 100 Solvent Neutral mineral oil to a concentra-
tion of at least 1% by weight at 25°C.
