Note: Descriptions are shown in the official language in which they were submitted.
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POWER TRANSMISSION FLUIDS WITH ENHANCED
ANTISHUDDER DURABILITY AND HANDLING CHARACTERISTICS
FIELD OF THE INVENTION
S
The present disclosure relates to fluids having improved friction durability
and
p/v characteristics on paper, metal and advanced friction materials. The
fluids disclosed
herein can exhibit improved handling characteristics, and improved anti-
shudder
durability. The invention includes devices, such as a power transmission
apparatus,
lubricated with such fluids.
BACKGROUND OF THE INVENTION
New and advanced transmission systems are being developed by the automotive
industry. These new systems often involve high energy requirements. Therefore,
component protection technology must be developed to meet the increasing
energy
requirements of these advanced systems, to promote fuel economy, and to extend
satisfactory friction requirements at low and high speeds.
These new and advance transmissions used in passenger cars and heavy duty
vehicles continue to become more sophisticated in design as vehicle technology
advances. These design changes result from the need to improve vehicle
operability,
reliability, and fuel economy. Vehicle manufacturers worldwide are increasing
vehicle
warranty periods and service intervals on their vehicles. This means that the
transmission and the transmission fluid must be designed to operate reliably
without
maintenance for longer periods of time. In the case of the fluid, this means
longer drain
intervals. To improve vehicle operability, especially at low temperature,
manufacturers
have imposed strict requirements for fluid viscosity at -40°C. To cope
with longer drain
intervals and more severe operating conditions, manufacturers have increased
the
requirements for fluid oxidation resistance, required less change in viscosity
with
vehicle mileage (improved shear stability), and increased the amount of wear
protection
that the fluid must provide for the transmission. To improve the fuel economy
of the
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vehicle and reduce energy loss, manufacturers nowadays employ continuously
slipping
clutches either as wet starting clutches or as a torque converter clutch.
These devices
require very precise control of fluid frictional properties.
The continuing search for methods to improve overall vehicle fuel economy has
S identified the torque converter, or fluid coupling, used between the engine
and automatic
transmission, as a relatively large source of energy loss. Since the torque
converter is a
fluid coupling it is not as efficient as a solid disk type clutch. At any set
of operating
conditions (engine speed, throttle position, ground speed, transmission gear
ratio), there
is a relative speed difference between the driving and driven members of the
torque
converter. This relative speed differential represents lost energy which is
dissipated
from the torque converter as heat.
One method of improving overall vehicle fuel economy used by transmission
builders is to build into the torque converter a clutch mechanism capable of
"locking"
the torque converter. "Locking" refers to eliminating relative motion between
the
driving and driven members of the torque converter so that no energy is lost
in the fluid
coupling. These "locking" or "lock-up" clutches are very effective at
capturing lost
energy at high road speeds. However, when they are used at low speeds, vehicle
operation is rough and engine vibration is transmitted through the drive
train. Rough
operation and engine vibration are not acceptable to drivers.
The higher the percentage of time that the vehicle can be operated with the
torque converter clutch engaged, the more fuel efficient the vehicle becomes.
A further
generation of torque converter clutches have been developed which operate in a
"slipping" or "continuously sliding mode." These devices have a number of
names, but
are commonly referred to as continuously slipping torque converter clutches.
The
difference between these devices and lock-up clutches is that they allow some
relative
motion between the driving and driven members of the torque converter,
normally a
relative speed of SO to 500 rpm. This slow rate of slipping allows for
improved vehicle
performance as the slipping clutch acts as a vibration damper. Whereas the
"lock-up"
type clutch could only be used at road speeds above approximately 50 mph, the
"slipping" type clutches can be used at speeds as low as 25 mph, thereby
capturing
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significantly more lost energy. It is this feature that makes these devices
very attractive
to vehicle manufacturers.
Another approach to reducing energy loss in the coupling between the engine
and transmission is to use a wet starting clutch. Wet starting clutches
resemble shifting
clutches but are made to handle the entire energy of the vehicle. Therefore
they tend to
be physically larger than shifting clutches. However, just as with the torque
converter
clutch, they are continuously slipped to improve overall vehicle driveability
and ride
feel.
Continuously slipping clutches have been fitted to all types of transmissions.
I O Continuously slipping torque converter clutches and/or wet starting
clutches are
routinely used with transmission types such as conventional automatic
transmissions,
continuously variable transmissions (CVTs), manual transmissions, and dual
clutch
transmissions.
Continuously slipping clutches, such as continuously slipping torque converter
clutches, impose very exacting friction requirements on automatic transmission
fluids
(ATFs) used with them. The fluid must have a very good friction versus
velocity
relationship, i.e., friction must always increase with increasing speed. If
friction
decreases with increasing speed then a self exciting vibrational state can be
set up in the
driveline. This phenomenon is commonly called "stick-slip" or "dynamic
frictional
vibration" and manifests itself as "shudder" or low speed vibration in the
vehicle. Clutch
shudder is very objectionable to the driver. A fluid which allows the vehicle
to operate
without vibration or shudder is said to have good "anti-shudder"
characteristics. Not
only must the fluid have an excellent friction versus velocity relationship
when it is new,
it must retain those frictional characteristics over the lifetime of the
fluid, which can be
the lifetime of the transmission. The longevity of the anti-shudder
performance in the
vehicle is commonly referred to as "anti-shudder durability."
Lubricating a continuously variable transmission equipped with a steel push
belt
or chain drive variator and a slipping clutch system is not a simple matter.
It presents a
unique challenge of providing high steel-on-steel friction for the variator
and excellent
paper-on-steel friction for the slipping clutch. Compounding the challenge to
satisfy
these requirements is the further need for the fluid to provide durability of
desired
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friction performance over a wide range of operating temperatures. Therefore,
the
friction modifier system must provide very precise control of the steel-on-
steel friction
and the paper-on-steel friction over a wide range of operating conditions,
such as a wide
range in temperatures.
Past efforts include those described in U.S. Patent No. 5,395,539, which are
said
to be imidazole-free, as well as those described in U.S. Patent Nos.
5,750,476;
5,811,377; 5,840,662; 5,840,663; EP 0393769 B2; EP 0877784 B1; among others.
Despite these past efforts there remains a need for compositions and methods
that can address the needs in the industry.
We have discovered certain compounds as described hereinbelow that are
readily formulated into power transmission fluids, such as for an automatic
transmission,
provide a unique solution for providing desired characteristics, such as
extending the
anti-shudder durability of the fluid.
SUMMARY OF THE INVENTION
An aspect of the present invention relates to an improved power transmitting
fluid having enhanced friction durability and p/v characteristics,
particularly one that
can exhibit a positive p/v curve and can maintain high static capacity during
expected
use, on paper, steel, and advanced friction materials such as carbon fiber.
Another aspect of the present invention is to provide a lubricant composition
that
carries minimal concern for skin sensitization and related health, safety, and
environmental issues.
In an aspect of the present invention, a composition and a method of improving
the anti-shudder durability of power transmitting fluids, particularly
automatic
transmission fluids, are provided.
An embodiment of the present invention is a fluid composition comprising a
lubricating base oil, a friction modifier produced by reacting a polyamine
with an
aliphatic mono acid such as oleic or isostearic acid under conditions to form
a mixture of
1,2-disubstituted imidazoline containing components, and, optionally, other
performance
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enhancing additives. Further acylation of residual active nitrogens with mono
or diacids
or anhydrides affords a fi-iction modifier ("FM") compounds) having enhanced
frictional and handling characteristics.
In one aspect of the invention, a fluid comprises a reaction product of
aliphatic
carboxylic acids with polyamines, and particularly a reaction product obtained
under
conditions to produce compounds that include 1,2- disubstituted imidazolines,
including such as compounds as represented by formulas I and II hereinbelow:
~N~N~NHz N N~/'~ N~- N Rt
Rt l H Jn ~I lH Jn
Rt
I ~d II
wherein the formulae RI can be selected from the group consisting C3 to C3o
straight
chain or branched alkyl, alkenyl, aryl, or a heteroatom derivative thereof, or
hydrocarbyl groups as oligomers/polymers derived from propylene isobutylene
and
higher olefins having terminal, internal and vinylidene double bonds, and
their
heteroatom derivatives; and "n" ranges from 0 to S; and/or such a reaction
product post-
treated with a second carboxylic acid or carboxylic acid derivative.
A fluid formulated as a power transimission fluid can contain an effective
amount of at least one oil soluble ashless dispersant, such as a succinimide
dispersant,
succinic ester dispersant, succininic ester-amide dispersant, Mannich base
dispersant,
phosphorylated and/or boronated forms thereof.
A fluid formulation according to an aspect of the invention may optionally
include commercially available supplemental additives such as, for example,
air
expulsion additives, antioxidants, corrosion inhibitors, foam inhibitors,
metallic
detergents, organic phosphorus compounds, seal-swell agents, viscosity index
improvers, EP additives used in their conventional amounts.
A fluid according to an aspect of the invention can be formulated for use in
an
industrial gear or an automotive gear. In an automotive aspect, a fluid can be
formulated
for use in a power transmitting apparatus, such as a transmission employing
one or more
of an electronically controlled converter clutch, a slipping torque converter,
a lock-up
torque converter, a starting clutch, and one or more shifting clutches; or a
differential.
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EP-7622
For example, a fluid containing a friction modifier comprised of compounds
represented
by formula I and/or II, or their post-treated reaction products, at least one
ashless
dispersant, and, optionally, one.or more other performance additives such as
antioxidants, anti foam agents, antiwear agents, corrosion inhibitors, EP
additives,
metallic detergents, organic phosphorus compound(s), rust inhibitors, seal-
swell agents
viscosity index improvers, can be used in automatic transmissions, including
those that
incorporate lock-up and dual clutches, semi-automatic transmissions, automated
manual
transmissions, and continuously variable transmissions ("CVTs").
The present invention includes such further embodiments as a method for
improving the stability against oxidation degradation, e.g. promoting the
duration of a
relatively constant dynamic coefficient of friction, in a power transmission
fluid by
incorporating into the fluid an effective amount of a friction modifier
compounds)
represented by a formula I to VI described herein.
Brief Description of the Figures
FIG. 1 represents side-by-side graphs to illustrate comparison between a
conventional automatic transmission fluid A and an automatic transmission
fluid B
according to this invention.
FIG. 2 is a diagram depicting apparatus for conducting a LFW-1 test.
Detailed Description of the Invention
Vehicles meeting stringent consumer demands require durability and
performance in all of the vehicular systems. One of the most important systems
is the
power transmission system ("transmission") which transmits the power generated
by the
automobile engine to the wheels. It is one of the most complex systems in the
vehicle, it
is also one of the most costly to diagnose, repair, or replace. The
transmission usually
includes, inter alia, a clutch with plates, a torque converter, and a
plurality of gears to
alter the power delivered to the wheels by changing the gear ratio.
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Discriminating consumers primarily desire high performance, low maintenance
(high mileage between servicing), and extended life expectancy. However, with
the
advent of new transmission technologies, old standards of performance which
were
previously met with approval are now becoming problematic.
The advent of electronically controlled converter clutch (ECCC) designs, as
well
as vehicles equipped with a continuously variable transmission (CVT) and
advances in
aerodynamic body design generally result in passenger cars with smaller
transmissions
which tend to operate with higher energy densities and higher operating
temperatures.
Such changes challenge lubricant suppliers to formulate automatic transmission
fluids
with new and unique performance characteristics including higher torque and
friction
durability. Original equipment manufacturers (OEMs) desire automatic
transmission
fluids with frictional characteristics capable of meeting the requirements of
ECCC,
CVT, and other designs while retaining sufficient performance in the antiwear
arena.
A long felt need exists for an effective way of overcoming the problems
associated with automatic transmissions, such as to meet the needs of OEM
automobile
designers and suppliers, for extended transmission fluid life and durability
of high static
capacity and improved durability of the dynamic coefficient of friction.
This invention responds to the long felt need for improved durability in a
lubricating fluid by providing an automatic transmission fluid that exhibits
good
performance during its lifetime and that can exhibit a sufficient dynamic
coefficient of
friction for longer periods of time without significant degradation, e.g.
improved
stability against oxidation, with extended anti-shudder durability.
Friction modifiers can be used in automatic transmission fluids to decrease
friction between surfaces (e.g., the members of a torque converter clutch or a
shifting
clutch) at low sliding speeds. The result is a friction-vs.-velocity (p-v)
curve that has a
positive slope, which in turn leads to smooth clutch engagements and minimizes
"stick-
slip" behavior (e.g., shudder, noise, and harsh shifts).
Increasing desired properties, such as anti-shudder durability and stability
against oxidation with reduced variation in the dynamic coefficient of
friction, is a
complex, challenging problem. Contrary to the apparently facile solution of
increasing
the amount of a conventional friction modifier in a power transmission fluid,
an
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increased concentration can actually reduce the overall level of friction
exhibited by the
fluid. Reducing the friction coefficients below certain minimum values is not
desired
since the holding capacitx of a clutch in a transmission can be adversely
reduced,
thereby making clutch slippage more likely when the transmission is being
operated.
S Clutch wear increases and a clutch can be ruined by unwanted slippage.
To address these and other challenges in the art, a fluid according to the
present
invention contains, as an essential component, a reaction product of an
aliphatic
carboxylic acid (RCOOH) and a polyamine (PA), for example a reaction product
obtained under conditions sufficient to generate a mixture of 1,2-
disubstituted
imidazolines represented by formulas I and/or II, and/or such a reaction
product which
is post-treated, such as with a second carboxylic acid or a carboxylic acid
derivative to
obtain compound represented by any of formulas III-VI. The composition of the
final
reaction product can be determined by the molar ratio between carboxylic acid
and the
polyamine.
Generalized structures I through VI exemplify typical friction modifiers for
use
in the various fluid embodiments according to the invention. These friction
modifiers
can form under conditions as described below.
A reaction product of a polyamine(s) with a first acid (RICOOH) can yield a
mixture containing a compound represented by formula I and a compound
represented
by formula II. A molar excess of the first organic acid is used relative to
the polyamine.
N~N~N~NHZ ' N N~ N~' N R~
R~ '' IL H ~n ~' lH Jn O
R~
I ~d I I
A molar ratio of the first carboxylic acid to the polyamine can vary according
to
the desired composition of the reaction product. In general, the molar ratio
can be
suitably chosen with a range of about 1.0 to about 2.0, and as a further
example, about
1.2 to about 1.6. For instance, at lower molar ratios the composition may in
principle
predominately be comprised of compounds) represented by formula I, whereas at
a
higher molar ratio the composition may in principle be predominately comprised
of
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compounds) represented by formula II. The molar ratio may correspond to an
excess
of the first carboxylic acid to polyamine.
Representative fist acids are those providing the R~ moieties. The R~ moieties
may be independent of one another, and can be C3 to C3o straight or branched
alkyl,
alkenyl or aryl groups or a heteroatom derivative thereof, such as an alkyl
having
heteroatoms, as one example. The present invention therefore contemplates, in
one of
its embodiments, using a combination of first acids. Representative moieties
include
fatty acids such as lauric, myristic, palinitic, stearic, isostearic,
dodecenoic,
hexadecenoic, oleic, iso-oleic, linoleic, arachidic, or a combination of any
thereof. The
Ri group may incorporate hydrocarbyl aromatic acids like 4-dodecylbenzoic
acid, 2-
hexadecylnicotinic acid, and 4-polyisobutyl acid. Suitable friction modifiers
include
those that are obtained from the reaction of fatty acids exemplified by oleic
acid or
isostearic acid with a polyamine, such as triethylene tetramine.
Heteroatom derivatives of Ri can include O, S, N, and/or P atoms as would be
understood by those skilled in the art.
Representative polyamines can be linear, as connoted by the compounds
represented by formulas I to VI (n= 0 to 5), or branched. An exemplary class
of
polyethylene amines contains an internal repeating unit of -(CHZ CHZNH)X-
where x can
be an integer from 1 to 10, and as a further example, x can be an integer of 1
to 6. In the
case where the polyamine is represented by a formula HZN-(CHZ CHZNH) X CHZ
CHZNH2, and x is 1 it is diethylene triamine, when x is 2 it is triethylene
tetramine, and
when x is 3 it is tetraethylene pentamine, which are among the suitable
polyamines.
Commercial mixtures of higher polyamines are also suitable. Amino groups can
be
attached to or be part of an aromatic or aliphatic ring structure, such as o-
phenylenediamine, p-phenylenediamine, 4,4'-diaminodiphenylamine, melamine, or
1,8-
diamino-p-mentane, among others.
For instance, reacting a selected first acid, such as C«H33COOH, and a
suitable
selected polyamine, such as where x = 2, in a molar ratio of about 4 to about
3 at a
suitable elevated temperature in a range of about 120°C to about
180°C, such as about
150°C, for a sufficient period of time, such as for about 5 to about 20
hours or, as a
further example, 'for about 12 to about 16 hours, can produce a reaction
product
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containing compounds) represented by the formulas I and II wherein RI is a
Cl~H3s
moiety. The relative ratio of the compound represented by the just described
formula I
to the compound represe>ated by the just described formula II can, in
principle, be about
2:1. Other ratios may be feasible. The relative ratio of a compounds)
represented by
formula I to a compounds) represented by formula II can be determined by the
ratio of
carboxylic acid to polyamine.
An embodiment of the invention is a fluid, such as a power transmission fluid
or
a concentrate, which contains at least one compound represented by formula I
and/or
formula II.
A post-treatment of a mixture (or reaction product) containing compounds)
represented by formulas I and/or II with at least one second organic acid
(R2COOH) can
be conducted. The second organic acid may be in an amount sufficient to
acylate all
reactive nitrogen atoms to obtain a second mixture (or second reaction
product)
containing a compounds) represented by formula III and a compounds)
represented by
formula IV:
~N~N~N~R~ ~N~N~N~R2
R~ ~O O R~ ~O O
Rz Rz
III ~d IV .
The level of acylation may, in general, be above about 0% to about 100%, and a
further
exemplary range can be, for instance, from about 50% to about 100%.
Representative second acids are those providing the RZ moieties. The RZ
moieties may be independent of one another, and can be C3 to C3o straight or
branched
alkyl, alkenyl, or aryl, or heteroatom derivatives thereof, such as an alkyl
having
heteroatoms, as one example. The present invention therefore also contemplates
using a
combination of first acids. Representative moieties include those from fatty
acids such
as lauric, myristic, palmytic, stearic, iso-stearic, dodecenoic, hexadecenoic,
oleic, iso-
oleic, linoleic, arachidic, or a mixture of any thereof. The RZ group may
incorporate
hydrocarbyl aromatic or heteroaromatic acids, such as 4-dodecylbenzoic acid, 2-
hexadecylnicotircic acid, or 4-polyisobutyl benzoic acid, among others.
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Heteroatom derivatives of RZ can include O, S, N, and/or P atoms as would be
understood by those skilled in the art.
An embodiment pf the-invention is a fluid, such as a power transmission fluid
or
a concentrate, which contains one or more compounds represented by structures
III and
IV.
A post-treatment of a mixture containing compounds represented by formulas I
and II with an excess of substituted anhydride, such as a substituted succinic
acid or
anhydride, can be conducted. The amount of the substituted organic acid or
anhydride
may be in an amount sufficient to acylate all or a portion of the reactive
nitrogens to
yield a mixture of compounds that includes a compounds) represented by formula
V
and a compounds) represented by formula VI:
H
R~
Ri Rs O O
R4 COOH
~d VI
The level of acylation may, in general, be above about 0% to about 100%, and a
further
exemplary range can be, for instance, from about 50% to about 100%.
Representative of the substituted organic acids and anhydrides are those
corresponding to the R3 and R4 moieties. The R3 and R4 moieties may be
independent of
each other, and may reflect the use of combinations of suitable reagents. The
R3 and R4
groups can be selected from a group consisting of H, -OH, -OR, -COOH, -SH, -
SR,
straight chain, branched alkyl, alkenyl radicals or hydrocarbyl groups in
oligomeric or
polymeric forms of propylene, isobutylene and higher olefins having terminal,
internal,
and vinylidene double bonds. The molecular weight of R3 and R4 can vary and
may be
as high as 1000 amu. The R represents an alkyl or alkenyl group having up to
30 carbon
atoms in linear, branched or cyclic form, for example from 16 to 22 carbon
atoms.
Accordingly, representative substituted organic acids and anhydrides include
low molecular weight, oil-insoluble acids or anhydrides. Examples include
succinic
anhydride, phthalic anhydride, tartaric acid, citric acid, malefic acid, and
mercaptosuccinic acid.
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A suitable post-treatment reagent is a succinic anhydride produced from
isomerization of linear a-olefins with an acid catalyst followed by reaction
with malefic
anhydride. Such preparation is~.described, for example, in U.S. Pat Nos. US
6,548,458;
5,620,486; 5,393,309; 5,021,169; US 4,958034; 4,234,435; 3,676,089; 3,361,673;
and
3,172,892 and European Patent 0623631 B l, herein incorporated by reference.
An embodiment of the invention is a fluid, such as a power transmission fluid
or
a concentrate, which contains one or more compounds) represented by formula V
and/or VI.
The friction modifiers) described above are idealized compositions in the
sense
that they don't incorporate cross-linking products and by-products due to
variation in the
level of acylation.
A fluid according to the invention can contain one or more compounds from
among those represented by formulas I to VI, including any combination of such
compounds. Suitable mixtures of compounds include, for instance, a mixture of
compounds represented by formula I, a mixture of compounds represented by
formula
II, a mixture of compounds represented by formula III, a mixture of compounds
represented by formula IV, a mixture of compounds represented by formula V, a
mixture of compounds represented by formula VI, a mixture of a compounds)
represented by formula I and a compounds) represented by formula II, a mixture
of a
compounds) represented by formula III and a compounds) represented by formula
IV,
a mixture of a compounds) represented by formula V and a compounds)
represented
by formula VI, a mixture of compounds from among those represented by formulas
I,
II, III, and IV, a mixture of compounds from among those represented by
formula I, II,
V and VI.
A combination of the suitable reactants and reagents can be selected to
produce a
friction modifier composition that contains a compounds) where Ri is oleyl or
isostearyl, and R3 and/or R4 is an isomerized a-olefin derived hydrocarbyl
group.
Further, R3 and/or R4 may comprise a moiety from polyisobutylene having a
molecular
weight of about 200 to about 950 amu or a Cib to C22 isomerized a-olefin.
Compounds represented by formulas I to VI can each be borated, maleated,
treated with an inorganic acid, such as phosphoric, phosphorous and sulfuric
acids, as
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described in U.S. Patent Nos. 3,254,025; 3,502,677; 4,686,054; and 4,857,214.
The level of this component in a finished oil-containing power transmission
fluid may range from about O.QI to about 10 % (weight percent). A suitable
range is
from about 0.1 to about 5.0 % weight percent. For example, the component can
comprise a mixture of compounds represented by formula V and by formula VI.
Dispersants (Oil-Soluble)
In an aspect of the invention, the fluid can contain at least one oil soluble
type
dispersant, such as a succinimide dispersant, succinic ester dispersant,
succininic ester-
amide dispersant, Mannich base dispersant, phosphorylated and/or boronated
forms
thereof. The total dispersant content of a fluid, such as a power
transimission fluid,
according to the invention can vary from 0.1 to 20 weight percent. As a
further
example, the suitable range can be from about 2.0 to about 7.0 weight percent.
Oil-soluble dispersants may include ashless dispersants such as succinimide
dispersants, Mannich base dispersants, and polymeric polyamine dispersants.
Hydrocarbyl-substituted succinic acylating agents are used to make hydrocarbyl-
substituted succinimides. The hydrocarbyl-substituted succinic acylating
agents include,
but are not limited to, hydrocarbyl-substituted succinic acids, hydrocarbyl-
substituted
succinic anhydrides, the hydrocarbyl-substituted succinic acid halides
(especially the
acid fluorides and acid chlorides), and the esters of the hydrocarbyl-
substituted succinic
acids and lower alcohols (e.g., those containing up to 7 carbon atoms), that
is,
hydrocarbyl-substituted compounds which can function as carboxylic acylating
agents.
Hydrocarbyl substituted acylating agents are made by reacting a polyolefin or
chlorinated polyolefin of appropriate molecular weight with malefic anhydride.
Similar
carboxylic reactants can be used to make the acylating agents. Such reactants
may
include, but are not limited to, malefic acid, fiunaric acid, malic acid,
tartaric acid,
itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride,
mesaconic acid,
ethylmaleic anhydride, dimethylmaleic anhydride, ethylmaleic acid,
dimethylmaleic
acid, hexylmaleic acid, and the like, including the corresponding acid halides
and lower
aliphatic esters.
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The molecular weight of the olefin can vary depending upon the intended use of
the substituted succinic anhydrides. Typically, the substituted succinic
anhydrides will
have a hydrocarbyl group of from about 8 to about 500 carbon atoms. However,
substituted succinic anhydrides used to make lubricating oil dispersants will
typically
have a hydrocarbyl group of about 40 to about 500 carbon atoms. With high
molecular
weight substituted succinic anhydrides, it is more accurate to refer to number
average
molecular weight (Mn) since the olefins used to make these substituted
succinic
anhydrides may include a mixture of different molecular weight components
resulting
from the polymerization of low molecular weight olefin monomers such as
ethylene,
propylene, and isobutylene.
The mole ratio of malefic anhydride to olefin can vary widely. It may vary,
for
example, from about 5:1 to about 1:5, or for example, from about 1:1 to about
3:1. With
olefins such as polyisobutylene having a number average molecular weight of
about S00
to about 7000, or as a further example, about 800 to about 3000 or higher and
the
ethylene-alpha-olefin copolymers, the malefic anhydride may be used in
stoichiometric
excess, e.g. about 1.1 to about 3 moles malefic anhydride per mole of olefin.
The
unreacted malefic anhydride can be vaporized from the resultant reaction
mixture.
Polyalkenyl succinic anhydrides may be converted to polyalkyl succinic
anhydrides by using conventional reducing conditions such as catalytic
hydrogenation.
For catalytic hydrogenation, a suitable catalyst is palladium on carbon.
Likewise,
polyalkenyl succinimides may be converted to polyalkyl succinimides using
similar
reducing conditions.
The polyalky( or polyalkenyl substituent on the succinic anhydrides employed
herein is generally derived from polyolefins, which are polymers or copolymers
of
mono-olefins, particularly 1-mono-olefins, such as ethylene, propylene, and
butylene.
The mono-olefin employed may have about 2 to about 24 carbon atoms, or as a
further
example, about 3 to about 12 carbon atoms. Other suitable mono-olefins include
propylene, butylene, particularly isobutylene, 1-octene, and 1-decene.
Polyolefins
prepared from such mono-olefins include polypropylene, polybutene,
polyisobutene,
and the polyalphaolefins produced from 1-octene and 1-decene.
14
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EP-7622
In some embodiments, the ashless dispersant may include one or more alkenyl
succinimides of an amine having at least one primary amino group capable of
forming
an imide group. The alkanyl succinimides may be formed by conventional methods
such as by heating an alkenyl succinic anhydride, acid, acid-ester, acid
halide, or lower
alkyl ester with an amine containing at least one primary amino group. The
alkenyl
succinic anhydride may be made readily by heating a mixture of polyolefin and
malefic
anhydride to about 180°C-220°C. The polyolefin may be a polymer
or copolymer of a
lower mono-olefin such as ethylene, propylene, isobutene, and the like, having
a number
average molecular weight in the range of about 300 to about 3000 as determined
by gel
permeation chromatography (GPC).
Amines which may be employed in forming the ashless dispersant include any
that have at least one primary amino group which can react to form an imide
group and
at least one additional primary or secondary amino group and/or at least one
hydroxyl
group. Representative examples include: N-methyl-propanediamine, N-
dodecylpropanediamine, N-aminopropyl-piperazine, ethanolamine, N-ethanol-
ethylenediamine, and the like.
Suitable amines may include alkylene polyamines, such as propylene diamine,
dipropylene triamine, di-(1,2-butylene)triamine, and tetra-(1,2-
propylene)pentamine. A
further example includes the ethylene polyamines which can be depicted by the
formula
HZN(CHZCHZNH)~H, wherein n may be an integer from about 1 to about 10. These
include: ethylene diamine, diethylene triamine (DETA), triethylene tetramine
(TETA),
tetraethylene pentamine (TEPA), pentaethylene hexamine (PEHA), and the like,
including mixtures thereof in which case n is the average value of the
mixture. Such
ethylene polyamines have a primary amine group at each end so they may form
mono-
alkenylsuccinimides and bis-alkenylsuccinimides. Commercially available
ethylene
polyamine mixtures may contain minor amounts of branched species and cyclic
species
such as N-aminoethyl piperazine, N,N'-bis(aminoethyl)piperazine, N,N'-
bis(piperazinyl)ethane, and like compounds. The commercial mixtures may have
approximate overall compositions falling in the range corresponding to
diethylene
triamine to tetraethylene pentamine. The molar ratio of polyalkenyl succinic
anhydride
to polyalkylene polyamines may be from about 1:1 to about 3.0:1.
CA 02515624 2005-08-10
EP-7622
In some embodiments, the ashless dispersant may include the products of the
reaction of a polyethylene polyamine, e.g., triethylene tetramine or
tetraethylene
pentamine, with a hydrooarbomsubstituted carboxylic acid or anhydride made by
reaction of a polyolefin, such as polyisobutene, of suitable molecular weight,
with an
unsaturated polycarboxylic acid or anhydride, e.g., malefic anhydride, malefic
acid,
fumaric acid, or the like, including mixtures of two or more such substances.
Polyamines that are also suitable in preparing the dispersants described
herein
include N-arylphenylenediamines, such as N-phenylphenylenediamines, for
example,
N-phenyl-1,4-phenylenediamine, N-phenyl-1,3-phenylenediamine, and N-phenyl-1,2
phenylenediamine; aminothiazoles such as aminothiazole, aminobenzothiazole,
aminobenzothiadiazole, and aminoalkylthiazole; aminocarbazoles; aminoindoles;
aminopyrroles; amino-indazolinones; aminomercaptotriazoles; aminoperimidines;
aminoalkyl imidazoles, such as 1-(2-aminoethyl) imidazole, 1-(3-aminopropyl)
imidazole; and aminoalkyl morpholines, such as 4-(3-aminopropyl) morpholine.
These
1 S polyamines are described in more detail in U.S. Patent Nos. 4,863,623 and
5,075,383.
Such polyamines can provide additional benefits, such as anti-wear and
antioxidancy, to
the final products.
Additional polyamines useful in forming the hydrocarbyl-substituted
succinimides include polyamines having at least one primary or secondary amino
group
and at least one tertiary amino group in the molecule as taught in U.S. Patent
Nos.
5,634,95 l and 5,725,612. Examples of suitable polyamines include N,N,N",N"-
tetraalkyldialkylenetriamines (two terminal tertiary amino groups and one
central
secondary amino group), N,N,N',N"-tetraalkyltrialkylenetetramines (one
terminal
tertiary amino group, two internal tertiary amino groups and one terminal
primary amino
group), N,N,N',N",N"'-pentaalkyltrialkylenetetramines (one terminal tertiary
amino
group, two internal tertiary amino groups and one terminal secondary amino
group),
tris(dialkylaminoalkyl)-aminoalkylmethanes (three terminal tertiary amino
groups and
one terminal primary amino group), and like compounds, wherein the alkyl
groups are
the same or different and typically contain no more than about 12 carbon atoms
each,
and which may contain from about 1 to about 4 carbon atoms each. As a further
16
CA 02515624 2005-08-10
EP-7622
example, these alkyl groups may be methyl and/or ethyl groups. Polyamine
reactants of
this type may include dimethylaminopropylamine (DMAPA) and N-methyl
piperazine.
Hydroxyamines suitable for use herein include compounds, oligomers or
polymers containing at least one primary or secondary amine capable of
reacting with
S the hydrocarbyl-substituted succinic acid or anhydride. Examples of
hydroxyamines
suitable for use herein include aminoethylethanolamine (AEEA),
aminopropyldiethanolamine (APDEA), ethanolamine, diethanolamine (DEA),
partially
propoxylated hexamethylene diamine (for example HMDA-2P0 or HMDA-3P0), 3-
amino-1,2-propanediol, tris(hydroxymethyl)aminomethane, and 2-amino-1,3-
propanediol.
The mole ratio of amine to hydrocarbyl-substituted succinic acid or anhydride
may range from about 1:1 to about 3.0:1. Another example of a mole ratio of
amine to
hydrocarbyl-substituted succinic acid or anhydride may range from about 1.5:1
to about
2.0:1.
The foregoing dispersant may also be a post-treated dispersant made, for
example, by treating the dispersant with malefic anhydride and boric acid as
described,
for example, in U.S. Patent No. 5,789,353, or by treating the dispersant with
nonylphenol, formaldehyde and glycolic acid as described, for example, in U.S.
Patent
No. 5,137,980.
The Mannich base dispersants may be a reaction product of an alkyl phenol,
typically having a long chain alkyl substituent on the ring, with one or more
aliphatic
aldehydes containing from about 1 to about 7 carbon atoms (especially
formaldehyde
and derivatives thereof), and polyamines (especially polyalkylene polyamines).
For
example, a Mannich base ashless dispersants may be formed by condensing about
one
molar proportion of long chain hydrocarbon-substituted phenol with from about
1 to
about 2.5 moles of formaldehyde and from about 0.5 to about 2 moles of
polyalkylene
polyamine.
Hydrocarbon sources for preparation of the Mannich polyamine dispersants may
be those derived from substantially saturated petroleum fractions and olefin
polymers,
such as polymers of mono-olefins having from about 2 to about 6 carbon atoms.
The
hydrocarbon soui~ce generally contains, for example, at least about 40 carbon
atoms, and
17
CA 02515624 2005-08-10
EP-7622
as a further example, at least about 50 carbon atoms to provide substantial
oil solubility
to the dispersant. The olefin polymers having a GPC number average molecular
weight
between about 600 and about 5;000 are suitable for reasons of easy reactivity
and low
cost. However, polymers of higher molecular weight can also be used.
Especially
suitable hydrocarbon sources are isobutylene polymers and polymers made from a
mixture of isobutene and a rafFmate I stream.
Suitable Mannich base dispersants may be Mannich base ashless dispersants
formed by condensing about one molar proportion of long chain hydrocarbon-
substituted phenol with from about 1 to about 2.5 moles of formaldehyde and
from
about 0.5 to about 2 moles of polyalkylene polyamine.
Polymeric polyamine dispersants suitable as the ashless dispersants are
polymers
containing basic amine groups and oil solubilizing groups (for example,
pendant alkyl
groups having at least about 8 carbon atoms). Such materials are illustrated
by
interpolymers formed from various monomers such as decyl methacrylate, vinyl
decyl
ether or relatively high molecular weight olefins, with aminoalkyl acrylates
and
aminoalkyl acrylamides. Examples of polymeric polyamine dispersants are set
forth in
U.S. Patent Nos. 3,329,658; 3,449,250; 3,493,520; 3,519,565; 3,666,730;
3,687,849; and
3,702,300. Polymeric polyamines may include hydrocarbyl polyamines wherein the
hydrocarbyl group is composed of the polymerization product of isobutene and a
raffmate I stream as described above. PIB-amines and PIB-polyamines may also
be
used.
Methods for the production of ashless dispersants as described above are known
to those skilled in the art and are reported in the patent literature. For
example, the
synthesis of various ashless dispersants of the foregoing types is described
in such
patents as U.S. Patent Nos. 2,459,112; 2,962,442, 2,984,550; 3,036,003;
3,163,603;
3,166,516; 3,172,892; 3,184,474; 3,202,678; 3,215,707; 3,216,936; 3,219,666;
3,236,770; 3,254,025; 3,271,310; 3,272,746; 3,275,554; 3,281,357; 3,306,908;
3,311,558; 3,316,177; 3,331,776; 3,340,281; 3,341,542; 3,346,493; 3,351,552;
3,355,270; 3,368,972; 3,381,022; 3,399,141; 3,413,347; 3,415,750; 3,433,744;
3,438,757; 3,442,808; 3,444,170; 3,448,047; 3,448,048; 3,448,049; 3,451,933;
3,454,497; 3,454;555; 3,454,607; 3,459,661; 3,461,172; 3,467,668; 3,493,520;
18
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EP-7622
3,501,405; 3,522,179; 3,539,633; 3,541,012; 3,542,680; 3,543,678; 3,558,743;
3,565,804; 3,567,637; 3,574,101; 3,576,743; 3,586,629; 3,591,598; 3,600,372;
3,630,904; 3,632,510; 3,632,511; 3,634,515; 3,649,229; 3,697,428; 3,697,574;
3,703,536; 3,704,308; 3,725,277; 3,725,441; 3,725,480; 3,726,882; 3,736,357;
3,751,365; 3,756,953; 3,793,202; 3,798,165; 3,798,247; 3,803,039; 3,804,763;
3,836,471; 3,862,981; 3,872,019; 3,904,595; 3,936,480; 3,948,800; 3,950,341;
3,957,746; 3,957,854; 3,957,855; 3,980,569; 3,985,802; 3,991,098; 4,006,089;
4,011,380; 4,025,451; 4,058,468; 4,071,548; 4,083,699; 4,090,854; 4,173,540;
4,234,435; 4,354,950; 4,485,023; 5,137,980; and Re 26,433, herein incorporated
by
reference.
An example of a suitable ashless dispersant is a borated dispersant. Borated
dispersants may be formed by boronating (borating) an ashless dispersant
having basic
nitrogen and/or at least one hydroxyl group in the molecule, such as a
succinimide
dispersant, succinamide dispersant, succinic ester dispersant, succinic ester-
amide
dispersant, Mannich base dispersant, or hydrocarbyl amine or polyamine
dispersant.
Methods that can be used for boronating the various types of ashless
dispersants
described above are described in U.S. Patent Nos. 3,087,936; 3,254,025;
3,281,428;
3,282,955; 2,284,409; 2,284,410; 3,338,832; 3,344,069; 3,533,945; 3,658,836;
3,703,536; 3,718,663; 4,455,243; and 4,652,387.
The borated dispersant may include a high molecular weight dispersant treated
with boron such that the borated dispersant includes up to about 2 wt. % of
boron. As
another example the borated dispersant may include from about 0.8 wt. % or
less of
boron. As a further example, the borated dispersant may include from about 0.1
to
about 0.7 wt. % of boron. As another example, the borated dispersant may
include from
about 0.25 to about 0.7 wt. % of boron. As a still further example, the
borated
dispersant may include from about 0.35 to about 0.7 wt. % of boron. The
dispersant
may be dissolved in oil of suitable viscosity for ease of handling. It should
be
understood that the weight percentages given here are for neat dispersant,
without any
diluent oil added.
A dispersant may be further reacted with an organic acid, an anhydride, and/or
an aldehyde/phenol mixture. Such a process may enhance compatibility with
elastomer
19
CA 02515624 2005-08-10
EP-7622
seals, for example. The borated dispersant may further include a mixture of
borated
dispersants. As a further example, the borated dispersant may include a
nitrogen-
containing dispersant and/or may be free of phosphorus.
Other Additives
The power transmission fluid may also include conventional additives of the
type used in automatic transmission fluid formulations and gear lubricants.
Such
additives include, but are not limited to antifoamants (foam inhibitors),
antioxidants,
anti-rust additives, antiwear additives, colorants, corrosion inhibitors,
dispersants, metal
deactivators, metallic detergents, organic phosphorus compounds, pour point
depressants, seal swell agents, and/ viscosity index improvers. Additives are
generally
described in C.V. Smalheer et al., Lubricant Additives, pages 1-11 (1967) and
in U.S.
Patent No. 4,105,571, among others. The supplemental additives include those
that are
commercially available.
Antifoam agents
In some embodiments, a fluid according to the present invention can include a
foam inhibitor(s), which is another component suitable for use in the
compositions.
Foam inhibitors may be selected from silicones, polyacrylates, surfactants,
and the like.
The amount of antifoam agent in the transmission fluid formulations described
herein
may range from about 0.001 wt.% to about 0.5 wt.% based on the total weight of
the
formulation. As a further example, antifoam agent may be present in an amount
from
about 0.01 wt.% to about 0.1 wt.%.
Antioxidant Additives
In some embodiments, antioxidant compounds may be included in the
compositions. Antioxidants include phenolic antioxidants, aromatic amine
antioxidants,
sulfurized phenolic antioxidants, and organic phosphites, among others.
Examples of
phenolic antioxidants include 2,6-di-tert-butylphenol, liquid mixtures of
tertiary
butylated phenols, 2,6-di-tert-butyl-4-methylphenol, 4,4'-methylenebis(2,6-di-
tert-
butylphenol),2,2'-methylenebis(4-methyl6-ter t-butylphenol), mixed methylene-
bridged
CA 02515624 2005-08-10
EP-7622
polyalkyl phenols, and 4,4'-thiobis(2-methyl-6-tert-butylphenol), N,N'-di-sec-
butyl-
phenylenediamine, 4-isopropylaminodiphenylamine, phenyl-a-naphthyl amine,
phenyl-
a-naphthyl amine, diarylamines such as diphenylamine and ring-alkylated
diarylamines
such as ring-alkylated diphenylamines. Examples include the sterically
hindered tertiary
butylated phenols, bisphenols and cinnamic acid derivatives and combinations
thereof.
The amount of antioxidant in the transmission fluid compositions described
herein may
range from about 0.01 to about 10 wt. % based on the total weight of the fluid
formulation. As a further example, antioxidant may be present in an amount
from about
0.1 wt. % to about 2.0 wt. %.
Anti-Rust Additives
A fluid composition according to the present invention may include one or more
rust or corrosion inhibitors. Such materials include monocarboxylic acids and
polycarboxylic acids. Examples of suitable monocarboxylic acids are octanoic
acid,
decanoic acid and dodecanoic acid. Suitable polycarboxylic acids include dimer
and
trimer acids such as are produced from such acids as tall oil fatty acids,
oleic acid,
linoleic acid, or the like. Another useful type of rust inhibitor may comprise
alkenyl
succinic acid and alkenyl succinic anhydride corrosion inhibitors such as, for
example,
tetrapropenylsuccinic acid, tetrapropenylsuccinic anhydride,
tetradecenylsuccinic acid,
tetradecenylsucciruc anhydride, hexadecenylsuccinic acid, hexadecenylsuccinic
anhydride, and the like. Also useful are the half esters of alkenyl succinic
acids having
about 8 to about 24 carbon atoms in the alkenyl group with alcohols such as
the
polyglycols. Other suitable rust or corrosion inhibitors include ether amines;
acid
phosphates; amines; polyethoxylated compounds such as ethoxylated amines,
ethoxylated phenols, and ethoxylated alcohols; imidazolines; aminosuccinic
acids or
derivatives thereof, and the like. Materials of these types are commercially
available.
Mixtures of such rust or corrosion inhibitors can be used. The amount of rust
inhibitor
in the transmission fluid formulations described herein may range from about
0.01 to
about S.0 wt.% based on the total weight of the formulation.
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EP-7622
Antiwear Additives
The antiwear characteristics of a finished fluid optionally may be modified by
addition of one or more supplemental antiwear agents. The supplemental
antiwear
agents may include phosphorus-containing antiwear agents, such as those
comprising an
organic ester of phosphoric acid, phosphorous acid, or an amine salt thereof.
For
example, the phosphorus-containing antiwear agent may include one or more of a
dihydrocarbyl phosphate, a trihydrocarbyl phosphate, a dihydrocarbyl
phosphate, a
trihydrocarbyl phosphate, any sulfur analogs thereof, and any amine salts
thereof. As a
further example, the phosphorus-containing antiwear agent may include at least
one of
dibutyl hydrogen phosphate and an amine salt of sulfurized dibutyl hydrogen
phosphate.
The phosphorus-containing antiwear agent may be present in an amount
sufficient to provide about 50 to about 500 parts per million by weight of
phosphorus in
the power transmission fluid. As a further example, the phosphorus-containing
antiwear
agent may be present in an amount sufficient to provide about 150 to about 300
parts per
1 S million by weight of phosphorus in the power transmission fluid.
The power transmission fluid may include from about 0.01 wt. % to about S.0
wt. % of the phosphorus-containing antiwear agent. As a further example, the
power
transmission fluid may include from about 0.2 wt. % to about 0.3 wt. % of the
phosphorus-containing antiwear agent. As an example, the power transmission
fluid
may include from about 0. I wt. % to about 0.2 wt. % of a dibutyl hydrogen
phosphate or
0.3 wt. % to about 0.4 wt. % an amine salt of a sulfurized dibutyl hydrogen
phosphate.
Colorant (dye)
In some embodiments, a fluid according to the present invention can include a
colorant to give the fluid a detectable character. Generally, azo class dyes
are used, such
as C.I. Solvent Red 24 or C.I. Solvent Red 164, as set forth in the "Color
Index" of the
American Association of textile Chemists and Colorists and the Society of
Dyers and
Colourists (U.K.). For automatic transmission fluids, Automatic Red Dye is
preferred.
Dye is present in a very minimal amount, such as about 200 to about 300 ppm in
the
finished fluid.
22
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EP-7622
Corrosion Inhibitors
In some embodiments, a fluid according to the present invention can include
copper corrosion inhibitors. Suitable copper corrosion inhibitors include such
compounds as thiazoles, triazoles, and thiadiazoles. Examples of such
compounds
include benzotriazole, tolyltriazole, octyltriazole, decyltriazole,
dodecyltriazole, 2-
mercapto benzothiazole, 2,S-dimercapto-1,3,4-thiadiazole, 2-mercapto-5-
hydrocarbylthio-1,3,4-thiadiazoles, 2-mercapto-S- hydrocarbyldithio-1,3,4-
thiadiazoles,
2,5-bis(hydrocarbylthio)-1,3,4-thiadiazoles, and 2,5-bis(hydrocarbyldithio)-
1,3,4-
thiadiazoles. Suitable compounds include the 1,3,4-thiadiazoles, a number of
which are
available as articles of commerce, and also combinations of triazoles such as
tolyltriazole with a 1,3,5-thiadiazole such as a 2,5-bis(alkyldithio)-1,3,4-
thiadiazole.
Regarding dialkyl thiadiazoles, for imparting corrosion inhibition, that
additive
previously has been used in much smaller treat levels than the levels used in
the present
invention to enhance extreme pressure and antiwear properties (when used in
combination with relatively high levels of sulfurized fatty oil as indicated
herein). The
1,3,4-thiadiazoles are generally synthesized from hydrazine and carbon
disulfide by
known procedures. See, for example, U.S. Patent Nos. 2,765,289; 2,749,311;
2,760,933; 2,850,453; 2,910,439; 3,663,561; 3,862,798; and 3,840,549.
Other Friction Modifiers
A fluid according to the present invention containing a friction modifier
compound represented by a formula I - VI hereinabove, or any combination of
such
friction modifiers, may optionally be contain other friction modifiers,
including those
known in the art. Exemplary of such other friction modifiers are alkylated or
ethoxylated fatty amines, amides glycerol esters and different imidazolines
(or their
derivatives).
Other friction modifiers include such compounds as aliphatic amines or
ethoxylated aliphatic amines, ether amines, alkoxylated ether amines,
aliphatic fatty acid
amides, acylated amines, aliphatic carboxylic acids, aliphatic carboxylic
esters, polyol
esters, aliphatic carboxylic ester-amides, imidazolines, tertiary amines,
aliphatic
phosphonates, aliphatic phosphates, aliphatic thiophosphonates, aliphatic
23
CA 02515624 2005-08-10
EP-7622
thiophosphates, etc., wherein the aliphatic group usually contains one or more
carbon
atoms so as to render the compound suitably oil soluble. As a further example,
the
aliphatic group may contain about 8 or more carbon atoms. Also suitable are
aliphatic
substituted succinimides formed by reacting one or more aliphatic succinic
acids or
anhydrides with ammonia or primary amines.
The succinimide may include the reaction product of a succinic anhydride and
ammonia or primary amine. The alkenyl group of the alkenyl succinic acid may
be a
short chain alkenyl group, for example, the alkenyl group may include from
about 12 to
about 36 carbon atoms. Further, the succinimide may include an about C,Z to
about C36
aliphatic hydrocarbyl succinimide. As a further example, the succinimide may
include
an about C16 to about CZ8 aliphatic hydrocarbyl succinimide. As an even
further
example, the succinimide may include an about C,g to about C24 aliphatic
hydrocarbyl
succinimide.
The succinimide may be prepared from a succinic anhydride and ammonia as
described in European Patent Application No. 0 020 037, herein incorporated by
reference. In some embodiments, the succinimide may include one or more of a
compounds) having the following structure:
0
Z-CH-C'
~X
CH2 C\
O
wherein Z may have the structure:
R~
2 GH
R~
wherein either R~ or Rz may be hydrogen, but not both, and wherein R1 and RZ
may be
independently straight or branched chain hydrocarbon groups containing from
about I to
about 34 carbon atoms such that the total number of carbon atoms in R~ and RZ
is from
about 11 to about 35; X is an amino group derived from ammonia or a primary
amine;
24
CA 02515624 2005-08-10
EP-7622
and wherein, in addition to or in the alternative, the parent succinic
anhydride may be
formed by reacting malefic acid, anhydride, or ester with an internal olefin
containing
about 12 to about 36 carbon atoms, said internal olefin being formed by
isomerizing the
olefinic double bond of a linear a-olefin or mixture thereof to obtain a
mixture of
internal olefins. The reaction may involve an equimolar amount of ammonia and
may
be earned out at elevated temperatures with the removal of water.
One group of other friction modifiers includes the N-aliphatic hydrocarbyl-
substituted diethanol amines in which the N-aliphatic hydrocarbyl-substituent
is at least
one straight chain aliphatic hydrocarbyl group free of acetylenic unsaturation
and having
in the range of about 14 to about 20 carbon atoms.
An example of a suitable other friction modifier system is composed of a
combination of at least one N-aliphatic hydrocarbyl-substituted diethanol
amine and at
least one N-aliphatic hydrocarbyl-substituted trimethylene diamine in which
the N-
aliphatic hydrocarbyl-substituent is at least one straight chain aliphatic
hydrocarbyl
I S group free of acety(enic unsaturation and having in the range of about 14
to about 20
carbon atoms. Further details concerning this friction modifier system are set
forth in
U.S. Patent Nos. 5,372,735 and 5,441,656.
Another example of a suitable other friction modifier system is one based on
the
combination of (i) at least one di(hydroxyalkyl) aliphatic tertiary amine in
which the
hydroxyalkyl groups, being the same or different, each contain from about 2 to
about 4
carbon atoms, and in which the aliphatic group is an acyclic hydrocarbyl group
containing from about 10 to about 25 carbon atoms, and (ii) at least one
hydroxyalkyl
aliphatic imidazoline in which the hydroxyalkyl group contains from about 2 to
about 4
carbon atoms, and in which the aliphatic group is an acyclic hydrocarbyl group
containing from about 10 to about 25 carbon atoms. For further details
concerning this
friction modifier system, reference should be had to U.S. Patent No.
5,344,579.
Another suitable group of other friction modifiers includes po(yolesters, for
example, glycerol monooleate (GMO), glycerol monolaurate (GML), and the like.
Other friction modifiers include, for instance, those described in European
Patent Publications 87778481, 856042, and 988357; U.S. Patent Nos. 5,750,476
and
5,942,472; and P'CT patent publication WO 97/14772 (April 24, 1997), among
others.
CA 02515624 2005-08-10
EP-7622
In general, in a composition embodiment, the composition, such as a power
transmission fluid or an additive package, may contain up to about 5 wt. %,
or, as a
further example, from about 0.01 to about 3 wt. % of one or more of these
other,
additional, friction modifiers.
Metallic Detergents
Certain metallic detergents may optionally be included in an additive package
or
in a power transmission fluid of the present invention. A suitable metallic
detergent
may include an oil-soluble neutral or overbased salt of alkali or alkaline
earth metal with
one or more of the following acidic substances (or mixtures thereof): (1) a
sulfonic acid,
(2) a carboxylic acid, (3) a salicylic acid, (4) an alkyl phenol, (S) a
sulfurized alkyl
phenol, and (6) an organic phosphorus acid characterized by at least one
direct carbon-
to-phosphorus linkage. Such an organic phosphorus acid may include those
prepared by
the treatment of an olefin polymer (e.g., polyisobutylene having a molecular
weight of
about 1,000) with a phosphorizing agent such as phosphorus trichloride,
phosphorus
heptasulfide, phosphorus pentasulfide, phosphorus trichloride and sulfur,
white
phosphorus and a sulfur halide, or phosphorothioic chloride.
Suitable salts may include neutral or overbased salts of magnesium, calcium,
or
zinc. As a further example, suitable salts may include magnesium sulfonate,
calcium
sulfonate, zinc sulfonate, magnesium phenate, calcium phenate, and/or zinc
phenate.
See, e.g., U.S. Patent Nos. 6,482,778. These salts can be used alone or in
combination
with another additive. For example, in principle, a suitable calcium salt may
be included
in combination with other additives, such as an organic phosphate in a power
transmission fluid, an additive package, or in a concentrate.
Oil-soluble neutral metal-containing detergents are those detergents that
contain
stoichiometrically equivalent amounts of metal in relation to the amount of
acidic
moieties present in the detergent. Thus, in general the neutral detergents
will have a low
basicity when compared to their overbased counterparts. The acidic materials
utilized in
forming such detergents include carboxylic acids, salicylic acids,
alkylphenols, sulfonic
acids, sulfurized alkylphenols and the like.
The term'"overbased" in connection with metallic detergents is used to
designate
26
CA 02515624 2005-08-10
EP-7622
metal salts wherein the metal is present in stoichiometrically larger amounts
than the
organic radical. The commonly employed methods for preparing the overbased
salts
involve heating a mineral oil selution of an acid with a stoichiometric excess
of a metal
neutralizing agent such as the metal oxide, hydroxide, carbonate, bicarbonate,
or sulfide
at a temperature of about 50°C, and filtering the resultant product.
The use of a
"promoter" in the neutralization step to aid the incorporation of a large
excess of metal
likewise is known. Examples of compounds usefixl as the promoter include
phenolic
substances such as phenol, naphthol, alkyl phenol, thiophenol, sulfurized
alkylphenol,
and condensation products of formaldehyde with a phenolic substance; alcohols
such as
methanol, 2-propanol, octanol, ethylene glycol, stearyl alcohol, and
cyclohexyl alcohol;
and amines such as aniline, phenylene diamine, phenothiazine, phenyl-beta-
naphthylamine, and dodecylamine. A particularly effective method for preparing
the
basic salts comprises mixing an acid with an excess 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°C to 200°C.
Examples of suitable metal-containing detergents include, but are not limited
to,
neutral and overbased salts of such substances as neutral sodium sulfonate, an
overbased
sodium sulfonate, a sodium carboxylate, a sodium salicylate, a sodium phenate,
a
sulfurized sodium phenate, a lithium sulfonate, a lithium carboxylate, a
lithium
salicylate, a lithium phenate, a sulfizrized lithium phenate, a magnesium
sulfonate, a
magnesium carboxylate, a magnesium salicylate, a magnesium phenate, a sulfiu-
ized
magnesium phenate, a calcium sulfonate, a calcium carboxylate, a calcium
salicylate, a
calcium phenate, a sulfurized calcium phenate, a potassium sulfonate, a
potassium
carboxylate, a potassium salicylate, a potassium phenate, a sulfurized
potassium
phenate, a zinc sulfonate, a zinc carboxylate, a zinc salicylate, a zinc
phenate, and a
sulfurized zinc phenate. Further examples include a lithium, sodium,
potassium,
calcium, and magnesium salt of a hydrolyzed phosphosulfi.u~ized olefin having
about 10
to about 2,000 carbon atoms or of a hydrolyzed phosphosulfurized alcohol
and/or an
aliphatic-substituted phenolic compound having about 10 to about 2,000 carbon
atoms.
Even further examples include a lithium, sodium, potassium, calcium, and
magnesium
salt of an aliphatic carboxylic acid and an aliphatic substituted
cycloaliphatic carboxylic
27
CA 02515624 2005-08-10
EP-7622
acid and many other similar alkali and alkaline earth metal salts of oil-
soluble organic
acids. A mixture of a neutral or an overbased salt of two or more different
alkali and/or
alkaline earth metals can~be used. Likewise, a neutral and/or an overbased
salt of
mixtures of two or more different acids can also be used.
As is well known, overbased metal detergents are generally regarded as
containing overbasing quantities of inorganic bases, generally in the form of
micro
dispersions or colloidal suspensions. Thus the term "oil-soluble" as applied
to metallic
detergents is intended to include metal detergents wherein inorganic 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 much the same way
as if
they were fully and totally dissolved in the oil. Collectively, the various
metallic
detergents referred to herein above, are sometimes called neutral, basic, or
overbased
alkali metal or alkaline earth metal-containing organic acid salts.
Methods for the production of oil-soluble neutral and overbased metallic
detergents and alkaline earth metal-containing detergents are well known to
those skilled
in the art, and extensively reported in the patent literature. See, for
example, U.S. Patent
Nos. 2,001,108; 2,081,075; 2,095,538; 2,144,078; 2,163,622; 2,270,183;
2,292,205;
2,335,017; 2,399,877; 2,416,281; 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; 3,907,691; 4,100,085; 4,129,589; 4,137,184; 4,184,740;
4,212,752; 4,617,135; 4,647,387; and 4,880,550.
The metallic detergents utilized in this invention can, if desired, be oil-
soluble
boronated neutral and/or overbased alkali of alkaline earth metal-containing
detergents.
Methods for preparing boronated metallic detergents are described in, for
example, U.S.
Patent Nos. 3,480,548; 3,679,584; 3,829,381; 3,909,691; 4,965,003; and
4,965,004.
While any effective amount of the metallic detergents may be used to enhance
the benefits of this invention, typically these effective amounts will range
from about
0.01 to about S.0 wt. % in the finished fluid, or as a further example, from
about 0.05 to
about 3.0 wt. % in the finished fluid.
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EP-7622
Organic Phosphorus Additives
When formulated as a power transmission fluid, or as a concentrate or as an
additive package, a composition of the present invention can include an
organic
phosphate. As an example, an organic phosphate can have the structure: Ri-XZ-
(:X1)(R2X3)-X-RS wherein Rl, and RZ may independently be substituted or
unsubstituted
alkyl, aryl, alkylaryl or cycloalkyl having 1 to 24 carbon atoms and X, Xi, X2
and X3
can independently be sulfur or oxygen. R,, and RZ may also contain substituent
heteroatoms, in addition to carbon and hydrogen, such as chlorine, sulfur,
oxygen or
nitrogen; RS can be derived from a reactive olefin and can be either -CH2-CHR-
C(:O)O-
R6; -CHZ-CR~HRg; or R9-OC(:O)CHZ-CH--C(:O)O-Rlo where R is H or the same as
Rl,
R6, R~, R9 and Rio are the same as R,, and Rg is a phenyl or alkyl or alkenyl
substituted
phenyl moiety, the moiety having from 6 to 30 carbon atoms.
Seal Swell Agents
In some embodiments, a fluid according to the present invention can include a
seal swell agent, such as used in a transmission fluid composition, selected
from oil-
soluble diesters, oil-soluble sulfones, and mixtures thereof. Generally, the
most suitable
diesters include the adipates, azelates, and sebacates of C8-Ci3 alkanols (or
mixtures
thereof), and the phthalates of C4-C,3 alkanols (or mixtures thereof).
Mixtures of two or
more different types of diesters (e.g., dialkyl adipates and dialkyl azelates,
etc.) can also
be used. Examples of such materials include the n-octyl, 2-ethylhexyl,
isodecyl, and
tridecyl diesters of adipic acid, azelaic acid, and sebacic acid, and the n-
butyl, isobutyl,
pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, and tridecyl
diesters of
phthalic acid.
Other esters which may give generally equivalent performance are polyol
esters.
Suitable sulfone seal swell agents are described in U.S. Patent Nos. 3,974,081
and
4,029,587. Typically these products are employed at levels in the range of
about 0.1 wt.
to about 10.0 wt. % in the finished transmission fluid. As a further example,
they
may be provided in an amount of about 0.25 wt. % to about 1.0 wt. %.
Suitable seal swell agents are the oil-soluble dialkyl esters of (i) adipic
acid, (ii)
sebacic acid, or (iii) phthalic acid. The adipates and sebacates should be
used in
29
CA 02515624 2005-08-10
EP-7622
amounts in the range of from about 1.0 to about 15.0 wt. % in the finished
fluid. In the
case of the phthalates, the levels in the transmission fluid should fall in
the range of from
about 1.5 to about 10.0 vut. %. ~'renerally, the higher the molecular weight
of the
adipate, sebacate or phthalate, the higher should be the treat rate within the
foregoing
ranges.
Viscosity Index Additives
A fluid composition embodiment of the invention may include one or more
viscosity index improvers. Since the fluid composition can be used as a fluid
transmission or gear lubricant composition, suitable viscosity index additives
include
any conventional viscosity index improvers. In general, exemplary classes of
viscosity
index additives are polyisoalkylene compounds and polymethacrylate compounds,
among others. An example of a suitable polyisoalkylene compound for use as a
viscosity index improver includes polyisobutylene having a weight average
molecular
weight ranging from about 700 to about 2,500. Embodiments may include a
mixture of
one or more viscosity index improvers of the same or different molecular
weight.
Suitable viscosity index improvers may include styrene-malefic esters,
polyalkylmethacrylates, and olefin copolymer viscosity index improvers.
Mixtures of
the foregoing products can also be used as well as dispersant and dispersant-
antioxidant
viscosity index improvers.
Additive Package - Diluent
If a friction modifier compound represented by any of formula I through VI, or
a
mixture of any such compounds, is provided in an additive package (sometimes
called a
concentrate), the concentrate includes a suitable carrier diluent is added to
ease blending,
solubilizing ingredients, and transporting the additive package. The diluent
oil needs to
be compatible with the base oil and the other ingredients that comprise an
additive
package. An additive package can comprise a major amount of an additive
comprised
of effective amounts of at least one friction modifiers) represented by
formula I to VI, a
minor amount of a diluent oil, and, optionally, other desired, compatible
additives. The
diluent can be present, for instance, in the concentrate in an amount of
between about S
CA 02515624 2005-08-10
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to about 20%, although it can vary widely with application. Generally
speaking, less
diluent is preferable as it lowers transportation costs and treat rates.
Additives used in formulating the compositions described herein can be blended
into base oil individually or in various sub-combinations. However, it is
suitable to
blend all of the components concurrently using an additive concentrate (i.e.,
additives
plus a diluent, such as a hydrocarbon solvent). The use of an additive
concentrate takes
advantage of the mutual compatibility afforded by the combination of
ingredients when
in the form of an additive concentrate. Also, the use of a concentrate reduces
blending
time and lessens the possibility of blending errors.
Finished Products and Base Oil
A finished power transmission fluid according to the present invention
typically
(but not necessarily always) is formulated with a major amount of a base oil
and a minor
amount of an additive package which includes at least one compound represented
by
1 S formula I, II, III, IV, V and/or VI at an effective addition level.
In one embodiment, a power transmission fluid composition is formulated to
contain a major amount of base oil and an effective but minor amount of a
fluid
containing at least one fluid modifier represented by a formula I to VI. An
exemplary
power transmission fluid can contain about 1.0 wt. % to about 25 wt. % of an
additive
composition containing a fluid composition according to the present invention.
Base oils suitable for use in formulating transmission fluid compositions
according to the invention may be selected from any of the synthetic or
natural oils or
mixtures thereof. Natural oils include animal oils and vegetable oils (e.g.,
castor oil, lard
oil) as well as mineral lubricating oils such as liquid petroleum oils and
solvent treated
or acid-treated mineral lubricating oils of the paraffinic, naphthenic or
mixed paraffinic-
naphthenic types. Oils derived from coal or shale are also suitable. The base
oil
typically has a viscosity of, for example, from about 2 to about 15 cSt and,
as a further
example, from about 2 to about 10 cSt at 100°C. Further, oils derived
from a gas-to-
liquid process are also suitable.
Synthetic oils include hydrocarbon oils such as polymerized and
interpolymerized olefins (e.g., polybutylenes, polypropylenes, propylene
isobutylene
31
CA 02515624 2005-08-10
EP-7622
copolymers, etc.); polyalphaolefins such as poly(1-hexenes), poly-(1-octenes),
poly(1-
decenes), etc. and mixtures thereof; alkylbenzenes (e.g., dodecylbenzenes,
tetradecylbenzenes, di-nc~nylbetlzenes, di-(2-ethylhexyl)benzenes, etc.);
polyphenyls
(e.g., biphenyls, terphenyl, alkylated polyphenyls, etc.); alkylated diphenyl
ethers and
S alkylated diphenyl sulfides and the derivatives, analogs and homologs
thereof and the
like.
Alkylene oxide polymers and interpolymers and derivatives thereof where the
terminal hydroxyl groups have been modified by esterification, etherification,
etc.,
constitute another class of known synthetic oils that may be used. Such oils
are
exemplified by the oils prepared through polymerization of ethylene oxide or
propylene
oxide, the alkyl and aryl ethers of these polyoxyalkylene polymers (e.g.,
methyl-
polyisopropylene glycol ether having an average molecular weight of about
1000,
diphenyl ether of polyethylene glycol having a molecular weight of about 500-
1000,
diethyl ether of polypropylene glycol having a molecular weight of about 1000-
1500,
etc.) or mono- and polycarboxylic esters thereof, for example, the acetic acid
esters,
mixed C3_g fatty acid esters, or the C,3 oxo acid diester of tetraethylene
glycol.
Another class of synthetic oils that may be used includes the esters of
dicarboxylic acids (e.g., phthalic acid, succinic acid, alkyl succinic acids,
alkenyl
succinic acids, malefic acid, azelaic acid, suberic acid, sebacic acid,
fumaric acid, adipic
acid, linoleic acid dimer, malonic acid, alkyl malonic acids, alkenyl malonic
acids, etc.)
with a variety of alcohols (e.g., butyl alcohol, hexyl alcohol, dodecyl
alcohol, 2-
ethylhexyl alcohol, ethylene glycol, diethylene glycol monoether, propylene
glycol, etc.)
Specific examples of these esters include dibutyl adipate, di(2-
ethylhexyl)sebacate, di-n-
hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate,
dioctyl phthalate,
didecyl phthalate, dieicosyl sebacate, the 2-ethylhexyl diester of linoleic
acid dimer, the
complex ester formed by reacting one mole of sebacic acid with two moles of
tetraethylene glycol and two moles of 2-ethylhexanoic acid and the like.
Esters useful as synthetic oils also include those made from CS to Clz
monocarboxylic acids and polyols and polyol ethers such as neopentyl glycol,
trimethylol propane, pentaerythritol, dipentaerythritol, tripentaerythritol,
etc.
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EP-7622
Hence, the base oil used which may be used to make the transmission fluid
compositions as described herein may be selected from any of the base oils in
Groups I-
V as specified in the Amorican~etroleum Institute (API) Base Oil
Interchangeability
Guidelines.
Such base oil groups are as follows:
Base Oil
Group Sulfur (wt. Saturates Viscosity
%) (wt. %) Index
Group I > 0.03 and/or < 90 80 to 120
Group II < 0.03 And > 90 80 to 120
Group III < 0.03 And > 90 > 120
Group IV All polyalphaolefins
(PAOs)
Group V all others
not included
in Groups
I-IV
'Groups I-III are mineral oil base stocks.
As set forth above, the base oil may be a poly-alpha-olefin (PAO). Typically,
the poly-alpha-olefins are derived from monomers having from about 4 to about
30, or
from about 4 to about 20, or from about 6 to about 16 carbon atoms. Examples
of useful
PAOs include those derived from octene, decene, mixtures thereof, and the
like. PAOs
may have a viscosity of from about 2 to about 15, or from about 3 to about 12,
or from
about 4 to about 8 cSt at 100°C. Examples of PAOs include 4 cSt at
100°C poly-alpha-
olefins, 6 cSt at 100°C poly-alpha-olefins, and mixtures thereof.
Mixtures of mineral oil
1 S with the foregoing poly-alpha-olefins may be used.
The base oil may be an oil derived from Fischer-Tropsch synthesized
hydrocarbons. Fischer-Tropsch synthesized hydrocarbons are made from synthesis
gas
containing HZ and CO using a Fischer-Tropsch catalyst. Such hydrocarbons
typically
require further processing in order to be useful as the base oil. For example,
the
hydrocarbons may be hydroisomerized using processes disclosed in U.S. Patent
Nos.
6,103,099 or 6,180,575; hydrocracked and hydroisomerized using processes
disclosed in
U.S. Patent Nos. 4,943,672 or 6,096,940; dewaxed using processes disclosed in
U.S.
Patent No. 5,882,505; or hydroisomerized and dewaxed using processes disclosed
in
U.S. Patent Nos.~6,013,171; 6,080,301; or 6,165,949.
- 33
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EP-7622
Unrefined, refined and rerefmed oils, either natural or synthetic (as well as
mixtures of two or more of any of these) of the type disclosed hereinabove can
be used
in the base oils. Unrefined oils. are those obtained directly from a natural
or synthetic
source without further purification treatment. For example, a shale oil
obtained directly
from retorting operations, a petroleum oil obtained directly from primary
distillation or
ester oil obtained directly from an esterification process and used without
further
treatment would be an unrefined oil. Refined oils are similar to the unrefined
oils except
they have been further treated in one or more purification steps to improve
one or more
properties. Many such purification techniques are known to those skilled in
the art such
I O as solvent extraction, secondary distillation, acid or base extraction,
filtration,
percolation, etc. Rerefined oils are obtained by processes similar to those
used to obtain
refined oils applied to refined oils which have been already used in service.
Such
rerefined oils are also known as reclaimed or reprocessed oils and often are
additionally
processed by techniques directed to removal of spent additives, contaminants,
and oil
breakdown products.
In selecting any of the optional additives, it is important to ensure that the
selected components) is/are soluble or stably dispersible in the additive
package and
finished automatic transmission fluid ("ATF") composition, are compatible with
the
other components of the composition, and do not interfere significantly with
the
performance properties of the composition, such as the extreme pressure,
antiwear,
friction, anti-shudder, viscosity and/or shear stability properties, needed or
desired, as
applicable, in the overall finished composition.
In general, the ancillary additive components are employed in the oil in minor
amounts sufficient to improve the performance characteristics and properties
of the base
fluid. The amounts will thus vary in accordance with such factors as the
viscosity
characteristics of the base fluid employed, the viscosity characteristics
desired in the
finished fluid, the service conditions for which the finished fluid is
intended, and the
performance characteristics desired in the finished fluid.
However, generally speaking, the following generally concentrations (weight
percent unless otherwise indicated) of the additional components in the base
fluids are
illustrative.
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EP-7622
Additives are blended into a base oil in their respective amounts which
amounts
are sufficient to provide their expected performance. Representative effective
amounts
are illustrated as followsa
Component wt
Dispersant 1- 20
Viscosity Index Improver 0.1- 25
Antioxidant 0.01- 10
Corrosion Inhibitor 0.01-2
Detergents and Rust
Inhibitors 0.01- 5
Seal-swell Agent 0.1-10
Anti-foam Agent 0.001-0.1
Anti-wear Agents 0.01-0.5
Other Friction Modifiers 0.01- 5
Lubricating Base Oil Balance
It will be appreciated that the individual components employed can be
separately
blended into the base fluid or can be blended therein in various
subcombinations, if
desired. Ordinarily, the particular sequence of such blending steps is not
crucial.
Moreover, such components can be blended in the form of separate solutions in
a
diluent. It is preferable, however, to blend the additive components used in
the form of a
concentrate, as this simplifies the blending operations, reduces the
likelihood of blending
errors, and takes advantage of the compatibility and solubility
characteristics afforded by
the overall concentrate.
Additive concentrates can thus be formulated to contain all of the additive
components and if desired, some of the base oil component, in amounts
proportioned to
yield finished fluid blends consistent with the concentrations described
above. In most
cases, the additive concentrate will contain one or more diluents such as
light mineral
oils, to facilitate handling and blending of the concentrate. Thus
concentrates containing
CA 02515624 2005-08-10
EP-7622
up to about 50 wt. % of one or more diluents or solvents can be used, provided
the
solvents are not present in amounts that interfere with the low and high
temperature and
flash point characteristics and the performance of the finished power
transmission fluid
composition. In this regard, the additive components used pursuant to this
invention may
be selected and proportioned such that an additive concentrate or package
formulated
from such components will have a flash point of about 170°C or above,
using the ASTM
D-92 test procedure.
Power transmission fluids of the embodiments herein are formulated to provide
enhanced extreme pressure properties for applications where metal-to-metal
contact is
made under high pressures, e.g., pressures in excess of 2 GPa. Such fluids are
suitable
for automatic and manual transmissions such as step automatic transmissions,
continuously variable transmissions, automated manual transmissions, and dual
clutch
transmissions. High metal-to-metal contact pressures such as those found in
automotive
transmissions, for example, may cause damage to transmission parts if a fluid
is used
that does not possess sufficient properties, including extreme pressure
protection
characteristics. Power transmission fluid compositions as described herein
have
improved performance characteristics. Further, the power transmission fluids
of the
present disclosure also are suitable for use in transmissions with an
electronically
controlled converter clutch, a slipping torque converter, a lock-up torque
converter, a
starting clutch, and/or one or more shifting clutches. Such transmissions
include four-,
five-, six-, and seven-speed transmissions, and continuously variable
transmissions
(chain, belt, or disk type). They also may be used in gear applications, such
as industrial
gear applications and automotive gear applications. Gear-types may include,
but are not
limited to, spur, spiral bevel, helical, planetary, and hypoid gears. They may
be used in
axles, transfer cases, and the like. Further, they may also be useful in
metalworking
applications.
The so-called LFW-1 test involves measuring friction between a rotating steel
ring against a stationary block having a friction material of interest at a
given load and
temperature. A test cycle involves acceleration and deceleration modes between
zero
and a maximum speed of 0.5 m/sec. The X-axis and Y-axis in the graphs in FIG.
1
represent speed and coefficient of friction (p), respectively. End-points on
the curves,
36
CA 02515624 2005-08-10
EP-7622
being close to zero speed, are regarded as static coefficient of friction
(ps,~), while the
friction in mid-point (maximum speed) is regarded as dynamic coefficient of
friction
(pdy"). Surprisingly, a fluid according the invention exhibits a reduced
change (delta) in
the dynamic coefficient of friction, pd, between its fresh versus an aged
condition in
comparison to conventional fluids. Samples having p~/pd values higher than one
can be
said to exhibit shudder problem when used as a power transmission fluid; for
example, a
fluid according to the invention that has a fresh oil ps/ud value in a secure
shudder-free
range (~-0.9) can manifest a low delta in p~Jpd, while showing improved
(higher)
dynamic coefficient of friction on aging (FMs 8, 11, 12, 13, 14 in Table 1 ).
The smaller
the delta p.s/pd between fresh and aged, the better is the friction durability
and if pd
increases it can translate to more effective power transmitting capability in
dynamic
mode upon aging.
As shown in FIG. 1, there is less chance of a change overall in the dynamic
coefficient of friction for a power transmission fluid B according to the
invention versus
a conventional formulation A when the LFW 1 test was conducted on samples that
are
subjected to 296 hours of heating at 170°C under an air flow of l
OL/minute. Frictional
benefits of using the compositions described in this invention are illustrated
in FIG. 1
that graphically shows a LFW-1 friction test comparison between fresh and aged
oils.
Oil A contains oleic acid/TEPA-derived bisacylamide whereas, Oil B contains
oleic
acid/TETA-derived imidazoline reacted with 750 molecular weight PIBSA. Both
friction modifiers ("FMs") are at a level to provide 950 ppm of nitrogen to
the finished
fluid.
A fluid according to the present invention can be formulated for use in a
power
transmitting apparatus, including a power transmission fluid, such as an ATF,
in a
2S transmission. An aspect of the present invention is a transmission.
Exemplary
transmissions include those described in "Transmission and Driveline Design",
SAE
Paper Number SP-108, Society of Automotive Engineers, Warrendale PA 1995;
"Design of Practices: Passenger Car Automotive Transmissions", The Third
Edition,
SAE Publication # AE-18, Society of Automotive Engineers, Warrendale PA 1994;
and
"Automotive Transmission Advancements", SAE Paper Number SP-854, Society of
Automotive Engineers, Warrendale PA 1991.
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CA 02515624 2005-08-10
EP-7622
An aspect of the present invention includes a transmission containing a power
transmission fluid, provided the fluid contains, as a fluid modifier(s), at
least one
compound represented by a formula I, II, III, IV, V or VI, or a mixture of
compounds
of any of these formulas. For example, a suitable mixture may include a
compound
represented by a formula I and a compound represented by at least one of
formula II,
III, IV, V or VI. The transmission embodiment includes a belt, chain, or disk-
type
continuously variable transmission, a 4-, S-, 6-, or 7-speed automatic
transmission, a
manual transmission, a dual clutch transmission.
A further aspect of the invention is a vehicle comprising an engine and a
transmission, the transmission including a power transmission fluid as above-
described.
A vehicle can contain a differential, and therefore in another embodiment, a
vehicle
contains a differential including a lubricant containing a fluid composition
as above-
described. Vehicle includes without limitation a truck, an automobile, and a
piece of
mechanized farm equipment, such as a tractor or reaper.
EXAMPLES
Illustrative compositions suitable for use in the practice of this invention
are
presented in the following Examples, wherein all parts and percentages are by
weight
unless specified otherwise.
Example 1
Reaction of isostearic acid with triethylenetetramine (TETA) was performed in
a
2L 3-neck round bottom flask, equipped with a pressure equilibrated addition
funnel,
distillation condenser, and a mechanical stirrer. To stirred isostearic acid
(405.3 g),
2S TETA (153.0 g) was added drop-wise at 75° C. Addition continued
slowly below 100°C
until the reaction is no longer exothermic. After addition of the remaining
amine,
vacuum was applied (28" Hg) with caution and temperature was increased
gradually to
1 SO°C. The mixture was stirred under vacuum for 19 hours. The reaction
was expected
to form 44.9 g. of water. Total of 48.2 g of volatile material was collected
in a dry-ice
trap.
Following analysis, these results were obtained for the product: TAN (D-664)
38
CA 02515624 2005-08-10
EP-7622
3.1 mg KOH/g; TBN (D-2869) 262.8 mg KOH/g; KV (100) 20.22 cSt; N :10.97%
(Calc'd: 11.41%). IR (cm I): 1660, 1613, 1459, 1248, 1004, 726.
Example 2
Reaction product of Example 1 (67.2 g), a diluent oil (76.2 g) and C20-24
alkyl
succinic anhydride (87.5 g) from Dixie Chemical Company were charged into a
500 mL
round bottom flask equipped with a distillation condenser and a mechanical
stirrer. The
mixture was stirred at 100° C under vacuum (28" Hg) for 1 hour.
Analysis of the
resulting product gave: TAN (D-664) 31.1 mg KOH/g; TBN (D-2869) 37.6 mg KOH/g;
N: 3.18% (Calc'd: 3.38%). IR (cm ~): 1771, 1705, 1649.
Example 3
Reaction product of Example 1 (55.33 g), a diluent oil (55.91 g) and 200 mol.
wt. PIBSA (56.29 g) having activity of 3.34 meq/g were reacted under
conditions
described in Example 2. Analysis of the resulting product gave TAN (D-664)
28.8 mg
KOH/g; TBN (D-2869) 43.5 mg KOH/g; N: 3.61 % (Calc'd: 3.68%). IR (cm-~ ):
1778,
1705, 1642.
Example 4
Table 1 shows LFW-1 results for fresh and aged oils. An embodiment from the
broad composition described hereinabove was used to evaluate the following
friction
modifiers in LFW-1 Friction Test as shown in Table I. Data are plotted in FIG.
I .
Table 1 shows a number of examples of oil-containing fluid formulations
according to the present invention that provide good fresh oil friction
characteristics
(ps/pd c about 1.0) that undergo much less change after oxidation compared to
a
conventional formulation.
- 39
CA 02515624 2005-08-10
o T
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x:
CA 02515624 2005-08-10
EP-7622
In Table 1, OA is oleic acid; ISO is isostearic acid; TETA is triethylene
tetramine; and Czo-Za-ASA is an alkyl succinic anhydride where the alkyl group
is an
isomerized form of a mixture of CZO to Cz4 alpha-olefins. PIBSA refers to
polyisobutylene succinic anhydride and the designations 200MW, 350MW, and
750MW relate the molecular weights (amu).
Reference 1 and Reference 2 use Ethomeen T-12, which is a commercially
available ethoxylated tallowalkylamine from Akzo Nobel at equal nitrogen
content.
The friction modifiers (FM's) reported in Table I are prepared by a two-stage
process. In a first stage, a fatty acid is reacted with a polyamine, and in a
second stage,
the first stage products) are post-treated with an alkyl succinic anhydride.
More
particularly, a first stage product (OL/TETA or ISA/TETA) is post-treated with
an alkyl
succinic anhydride. The reaction stoichiometry is presented in Table 1. The
various
alkyl succinic anhydrides are also presented in Table 1. Example 1 describes
suitable
reaction conditions for the first stage. The FM9 is prepared by applying the
conditions
and procedures described in Example 1 for the first stage, and in Example 2
for the
second stage. The FM12 is prepared by applying the conditions and procedures
described in Example 1 for the first stage, and in Example 3 for the second
stage. The
other FM's in Table 1 are prepared using the same protocols as in Examples 1
and 2.
FM 1 through Ref 1 provide 970 ppm nitrogen to the finished fluid. The
duration
of stability against oxidation for these oils is tested for 198 hours at
170°C with bubbling
air at a rate of l OL/h.
The duration of stability against oxidation for oils containing FMl I through
Ref
2 were different in that the test was conducted for only 120 hours and the
nitrogen
contribution from these friction modifiers was 375 ppm.
For instance, values for ps/pd of a friction modifier composition (such as FM-
1
through FM-16) generally can be up to about 1.0, and as a further example may
be less
than about 0.9, while still avoiding shudder problems and exhibiting
sufficient durability
against oxidation.
The dynamic coefficient of friction, pd, is known to relate to effectives of
torque
transfer, and therefore to fuel efficiency. High numerical values for this
parameter (pd)
41
CA 02515624 2005-08-10
EP-7622
are suitable. In terms of friction durability, change in these parameters
resulting from
aging of the oil should be minimal. High delta values indicate that oil loses
its initial
friction characteristics asa result of thermal and oxidative stress.
At numerous places throughout this specification, reference has been made to a
number of U.S. Patents, European Patent Applications (published), PCT
International
patent publications, and literature references. All such cited documents are
expressly
incorporated in full into this disclosure as if fully set forth herein.
As used throughout the specification and claims, "a" and/or "an" may refer to
one or more than one. Unless otherwise indicated, all numbers expressing
quantities of
ingredients, properties such as molecular weight, percent, ratio, reaction
conditions, and
so forth used in the specification and claims are to be understood as being
modified in
all instances by the term "about." Accordingly, unless indicated to the
contrary, the
numerical parameters set forth in the specification and claims are
approximations that
may vary depending upon the desired properties sought to be obtained by the
present
invention. At the very least, and not as an attempt to limit the application
of the doctrine
of equivalents to the scope of the claims, each numerical parameter should at
least be
construed in light of the number of reported significant digits and by
applying ordinary
rounding techniques. Notwithstanding that the numerical ranges and parameters
setting
forth the broad scope of the invention are approximations, the numerical
values set forth
in the specific examples are reported as precisely as possible. Any numerical
value,
however, inherently contains certain errors necessarily resulting from the
standard
deviation found in their respective testing measurements.
While the present invention has been principally demonstrated hereinabove as a
power transmitting fluid for transmissions, it is contemplated that the
benefits of the
fluid embodiment are similarly applicable to other power transmitting fluids
included
within the scope of the present invention are gear oils, hydraulic fluids,
heavy duty
hydraulic fluids, industrial oils, power steering fluids, pump oils, tractor
fluids, and
universal tractor fluids, and apparatus embodiments include gears, hydraulic
mechanisms, power steering devices, pumps and the like incorporating a fluid
according
to the invention.
42
CA 02515624 2005-08-10
EP-7622
Other embodiments of the present invention will be apparent to those skilled
in
the art from consideration of the specification, Figure and practice of the
invention
disclosed herein. It is intended~that the specification and examples be
considered as
exemplary only, with a true scope and spirit of the invention being indicated
by the
following claims.
43
