FIELD OF THE INVENTION
[0001] The present disclosure relates to fluids having improved characteristics particularly
for extreme pressure and antiwear applications. The fluids disclosed herein may include
fluids suitable for use, for example, in power transmission applications.
BACKGROUND OF THE INVENTION
[0002] 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.
[0003] Extremely high metal-on-metal pressures are present in newer automatic and manual
transmissions such as step automatic transmissions, continuously variable transmissions,
and manual or automated manual transmissions. High pressures are also present in various
gear drive components such as automotive differentials and power transmission gear
drive components. The high pressures present in such transmission and gear drive components
mean that lubricants used in these systems must be suitable for such extreme pressure
applications to prevent wear and seizure of the rotating and contacting components.
Thus, there continues to be a need for additives which reduce wear and prevent seizure
under extremely high pressure operating conditions.
[0004] Commercially, it is known to add various additive packages to automatic transmission
fluid, including, among other things, extreme pressure agents, antiwear agents, antioxidant
systems, corrosion inhibitor systems, metal deactivators, anti-rust agents, friction
modifiers, dispersants, detergents, anti-foam agents, and viscosity index improvers.
However, not all additives interact predictably or well with one another.
SUMMARY OF THE INVENTION
[0005] The present invention relates to the improvement of extreme pressure and antiwear
performance of fluids by the inclusion therein of sulfurized fatty oil in an amount
sufficient to provide at least about 1,000 ppm sulfur to the fluid, and dialkyl thiadiazole
in an amount sufficient to provide at least about 500 ppm sulfur to the fluid. Extreme
pressure and antiwear performance are surprisingly improved for fluids that combine
sulfurized fatty oil and dialkyl thiadiazole components in levels introducing these
respective amounts of sulfur into the fluid.
[0006] In one embodiment, a fluid includes sulfurized fatty oil in an amount sufficient
to provide from about 1,000 ppm to about 2,500 ppm, particularly about 1,300 ppm to
about 2,100 ppm, sulfur to the fluid, and dialkyl thiadiazole in an amount sufficient
to provide from about 500 ppm to about 1,800 ppm, particularly about 550 to about
1,500 ppm, sulfur to the fluid.
[0007] In order to introduce sulfur in the above-indicated minimal levels, the sulfurized
fatty oil may be present in an amount of about 0.5 wt.% to about 5.0 wt.%, and the
dialkyl thiadiazole may be present in an amount an amount of about 0.15 wt.% to about
3.0 wt.%, based on total weight of the fluid composition. In one particular embodiment,
the sulfurized fatty oil used in the indicated amount is sulfurized transesterified
triglyceride, and the dialkyl thiadiazole used in the indicated amount is 2,5-bis(hydrocarbyldithio)-1,3,4-thiadiazole
or a derivative thereof.
[0008] In another embodiment, a fluid includes a major amount of base oil, and a minor amount
of an additive composition containing respective amounts of (A) sulfurized fatty oil
and (B) dialkyl thiadiazole which are effective to provide a transmission fluid exhibiting
failure loads which equal or exceed about 1750 pounds at 100°C and 150°C, as measured
according to a Falex EP test of ASTM D-3233. A power transmission fluid including
only one of components (A) or (B), but not both, in compliance with the above-indicated
minimum respective sulfur contribution amounts will not achieve the above-indicated
failure load performance criteria.
[0009] In another embodiment, an additive comprises (A) sulfurized fatty oil in an amount
sufficient to provide at least about 1,000 ppm sulfur to the fluid composition, and
(B) dialkyl thiadiazole in an amount sufficient to provide at least about 500 ppm
sulfur to the fluid composition.
[0010] In another embodiment, an additive composition contains respective amounts of (A)
sulfurized fatty oil and (B) dialkyl thiadiazole which, in combination, are effective,
to provide a transmission fluid exhibiting failure loads which equal or exceed about
1750 pounds at 100°C and 150°C, as measured according to a Falex EP test of ASTM D-3233.
[0011] In another embodiment, a method for improving extreme pressure and/or wear performance
in power transmitting apparatus comprises 1) adding a fluid to a power transmitting
apparatus, said fluid comprising (a) a base oil, and (b) an additive package comprising
sulfurized fatty oil in an amount sufficient to provide at least 1,000 ppm sulfur
to the fluid, and dialkyl thiadiazole in an amount sufficient to provide at least
500 ppm sulfur to the fluid; and 2) operating the fluid in the power transmitting
apparatus, wherein the extreme pressure and/or wear performance is improved relative
to the extreme pressure and/or wear performance of a transmission without said fluid.
[0012] In another embodiment, a method of increasing the service life of a transmission
comprises operating in a transmission a fluid comprising: a) a base oil, and (b) an
additive package comprising sulfurized fatty oil in an amount sufficient to provide
at least 1,000 ppm sulfur to the fluid, and dialkyl thiadiazole in an amount sufficient
to provide at least 500 ppm sulfur to the fluid, wherein the service life of the transmission
is improved relative to the service life of a transmission without said fluid.
[0013] The extreme pressure and antiwear enhanced additive compositions of embodiments of
this invention may be advantageously used in a wide variety of applications, including,
for example, in automatic transmission fluids, manual transmission fluids, fluids
used in dual clutch transmissions, fluids used in continuously variable transmissions,
and gear lubricants.
[0014] The foregoing general description and the following detailed description are exemplary
and explanatory only and are intended to provide further explanation of the present
invention, as claimed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] Vehicles meeting stringent demands of consumers 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 being 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.
[0016] 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.
[0017] 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.
[0018] As power transmission fluids are desired which operate under increasingly severe
conditions, the oils used to lubricate those transmissions ideally would be formulated
to endure higher temperatures and pressures. To reduce equipment problems and increase
the interval between transmission oil changes, the oil additive packages ideally would
be formulated so that important oil properties change as little as possible in the
face of these stresses. An important characteristic of a power transmission fluid
is its extreme pressure properties. High metal-on-metal contact pressures found in
newer automotive transmissions and in gear drives can cause damage to transmission
parts and gear drives if the lubricant used in the system is not formulated to provide
sufficient extreme pressure protective properties. Such damage may take the form,
e.g., of simple wear (scoring, trenching, or grooving) or micropitting, pitting, welding,
or spalling. All of these phenomena may lead ultimately to degradation in transmission
performance and/or breakage of critical transmission components.
[0019] A need exists for an effective way of overcoming the wear problem associated with
automatic transmissions, such as to meet the needs of OEM automobile designers and
suppliers, for extended transmission fluid life and durability.
[0020] This invention overcomes the durability and antiwear (extreme pressure) problem by
providing an automatic transmission fluid that exhibits good extreme pressure and
anti-wear performance during its lifetime.
[0021] In accordance with an embodiment of this invention there is provided a power transmission
fluid which surprisingly gives improved extreme pressure and antiwear performance.
To provide this improved performance, in one of its embodiments the power transmission
fluid contains sulfurized fatty oil in an amount sufficient to provide at least about
1,000 ppm sulfur to the fluid, and dialkyl thiadiazole in an amount sufficient to
provide at least about 500 ppm sulfur to the fluid. In another embodiment, the power
transmission fluid contains sulfurized fatty oil in an amount sufficient to provide
about 1,000 ppm to about 2,500 ppm, particularly about 1,300 ppm to about 2,100 ppm,
sulfur to the fluid, and dialkyl thiadiazole in an amount sufficient to provide about
500 ppm to about 1,800 ppm, particularly about 550 to about 1,500 ppm, sulfur to the
fluid. In a further embodiment, in addition to complying with the minimum sulfur contribution
amounts applicable to each of sulfurized fatty oil and dialkyl thiadiazole as set
forth herein, the combined sulfur added to the fluid by the sulfurized fatty oil and
dialkyl thiadiazole is least about 1,500 ppm, and particularly at least about 2,500
ppm, and more particularly at least about 3,000 ppm.
[0022] In one embodiment, the fluids of the present invention are used in formulating automatic
transmission fluids which exhibit failure loads which equal or exceed about 1750 pounds
at 100°C and 150°C, as measured according to a Falex EP test of ASTM D-3233. The Falex
EP test described in ASTM D-3233 is incorporated herein by reference. There are several
tests available to the lubricant and automotive industries to evaluate the extreme
pressure/antiwear-enhancing capability of a transmission fluid. One of the most challenging
of these tests is the Falex EP test, which measures the load at which an oil fails
to successfully lubricate the metal-metal contact between a rotating steel pin and
two Vee blocks. Lubricant failure is indicated either by failure to maintain torque
or by seizure of the blocks against the pin. The test is severe not only because of
the high loads involved, but also because of the high fluid temperatures (some specifications
call for oil temperatures of up to 150°C). It is not uncommon for an oil to perform
well in several industrial wear tests but at the same time show poor performance in
the Falex EP test.
[0023] In another embodiment of the present invention, a method of improving extreme pressure
and/or antiwear performance in automatic transmissions is set forth. The method comprises
adding to, and operating in, an automatic transmission fluid (ATF) comprising (1)
a major amount of a base oil and (2) a minor amount of an additive composition which
comprises, as essential components, sulfurized fatty oil and dialkyl thiadiazole in
the respective treat rates as described herein. "Operating", as used herein, includes,
but is not limited to, any functional utilization of the fluid including transmitting
power, lubricating, and wetting.
[0024] Although the additive composition Components described below are described occasionally
with reference to a function, that function may be one of other functions served by
the same component and should not be construed as a mandatory limiting function.
[0025] In an embodiment, a power transmission fluid may include a major amount of a base
oil and a minor amount of an additive composition. The additive composition includes
extreme pressure and antiwear performance improving amounts of a sulfurized fatty
oil and a dialkyl thiadiazole in combination.
Additive Package
Component (A): Sulfurized Fatty Oil
[0026] Component (A) comprises a sulfurized fatty oil. For purposes herein, "sulfurized
fatty oil" refers to sulfurized fatty acids, sulfurized fatty esters, individually
or as mixtures thereof. Sulfurized fatty acid esters are preferred. The sulfurized
fatty oils may be animal or vegetable in origin. Suitable sulfurized fatty oils include,
for example, a sulfurized fatty acid ester containing about 10% sulfur and a sulfurized
sperm oil containing about 10% sulfur.
[0027] In one particular embodiment, suitable sulfurized fatty oils include sulfurized transesterified
triglycerides, such as those described in U.S. Pat. No. 4,380,499, which descriptions
are incorporated herein by reference. In one embodiment, a sulfurized transesterified
triglyceride additive has a total acid component comprising no less than about 35
mol% saturated aliphatic acids and no more than about 65 mol% unsaturated fatty acids,
and wherein the total acid component is further characterized as comprising more than
about 20 mol% of monounsaturated acids, less than about 15 mol% of polyunsaturated
fatty acids, more than about 20 mol% saturated aliphatic acids having 6 to 16 carbon
atoms, including more than about 10 mol% saturated aliphatic acids having 6 to 14
carbon atoms, and less than about 15 mol% saturated aliphatic acids having 18 or more
carbon atoms. Suitable sulfurized fatty oils also include those such as those described
in U.S. Pat. No. 4,149,982, which descriptions are incorporated herein by reference.
[0028] Other suitable sulfurized fatty oils include, for example, sulfurized lard oils,
sulfurized fatty compounds, sulfurized methyl esters, sulfurized hydrocarbons, sulfurized
oleic acid, sulfurized fatty ester-polyalkanol amides, and sulfurized fatty olefins.
Component (B): Dialkyl Thiadiazole
[0029] Component (B) comprises a dialkyl thiadiazole, including but not limited to an ashless
dialkyl thiadiazole.
[0030] Dialkyl thiadiazoles suitable for the practice of the present invention may be of
the general formula (I):
wherein R
1 and R
2 may be the same or different hydrocarbyl groups, and x and y independently may be
integers from 0 to 8. In one aspect, R
1 and R
2 may be the same or different, linear, branched, or aromatic, saturated or unsaturated
hydrocarbyl group having from about 6 to about 18 carbon atoms, particularly from
about 8 to about 12 carbon atoms, and x and y each may be 0 or 1.
[0031] An suitable dialkyl thiadiazoles includes 2,5-bis(hydrocarbyldithio)-1,3,4-thiadiazoles.
Examples of other suitable dialkyl thiadiazoles include, for example, 2,5-bis(hydrocarbylthio)-1,3,4-thiadiazoles,
2-(tert-hydrocarbyldithio)-5-mercapto-1,3,4-thiadiazoles, and bis-tert-dodecylthiothiadiazole.
[0032] Suitable dialkyl thiadiazoles also include those such as described in U.S. Pat. Nos.
2,719,125, 2,719,126, 3,087,932, 4,149,982, and 4,591,645, and which descriptions
are incorporated herein by reference. Mixtures of dialkyl thiadiazoles of formula
(I) with monoalkyl thiadiazoles may also be used within the scope of the present invention.
[0033] As used herein, the term "hydrocarbyl group" or "hydrocarbyl" is used in its ordinary
sense, which is well-known to those skilled in the art. Specifically, it refers to
a group having a carbon atom directly attached to the remainder of a molecule and
having a predominantly hydrocarbon character. Examples of hydrocarbyl groups include:
(1) hydrocarbon substituents, that is, aliphatic (e.g., alkyl or alkenyl), alicyclic
(e.g., cycloalkyl, cycloalkenyl) substituents, and aromatic-, aliphatic-, and alicyclic-substituted
aromatic substituents, as well as cyclic substituents wherein the ring is completed
through another portion of the molecule (e.g., two substituents together form an alicyclic
radical);
(2) substituted hydrocarbon substituents, that is, substituents containing non-hydrocarbon
groups which, in the context of the description herein, do not alter the predominantly
hydrocarbon substituent (e.g., halo (especially chloro and fluoro), hydroxy, alkoxy,
mercapto, alkylmercapto, nitro, nitroso, and sulfoxy);
(3) hetero-substituents, that is, substituents which, while having a predominantly
hydrocarbon character, in the context of this description, contain other than carbon
in a ring or chain otherwise composed of carbon atoms. Heteroatoms include sulfur,
oxygen, nitrogen, and encompass substituents such as pyridyl, furyl, thienyl, and
imidazolyl. In general, no more than two, or as a further example, no more than one,
non-hydrocarbon substituent will be present for every ten carbon atoms in the hydrocarbyl
group; typically, there will be no non-hydrocarbon substituent in the hydrocarbyl
group.
Combined Use of Components (A) and (B)
[0034] Extreme pressure and antiwear characteristics are improved for a power transmission
fluid which is formulated to contain a major amount of a base oil, and an additive
composition providing at least about 0.5 wt.% of the sulfurized fatty oil (Component
(A)) and at least about 0.15 wt.% of the dialkyl thiadiazole (Component (B)), based
on the total weight of the base oil and additive composition. In an embodiment, the
fluid composition contains sulfurized fatty oil in an amount of about 0.7 wt.% to
about 5.0 wt.%, particularly about 0.73 wt.% to about 3.0 wt.%, and more particularly
0.75 wt.% to about 3.0 wt.%; and dialkyl thiadiazole is present in an amount of about
0.15 wt.% to about 3.0 wt.%, particularly about 0.3 wt.% to about 1.0 wt.%, and more
particularly 0.35 wt.% to about 1.0 wt.%, based on total weight of the fluid composition.
[0035] A power transmission fluid including only one of components (A) or (B), but not both,
in compliance with the above-indicated minimum respective sulfur contribution amounts
can not predictably provide a transmission fluid exhibiting failure loads which equal
or exceed about 1750 pounds at 100°C and 150°C, respectively, as measured according
to a Falex EP test of ASTM D-3233.
Other Additive Components
[0036] The power transmission fluid may also include conventional additives of the type
used in automatic transmission fluid formulations and gear lubricants in addition
to the extreme pressure and antiwear performance improving co-additives described
above. Such additives include, but are not limited to, metallic detergents, dispersants,
friction modifiers, antioxidants, viscosity index improvers, copper corrosion inhibitors,
anti-rust additives, antiwear additives, antifoamants, pour point depressants, seal
swell agents, colorants, metal deactivators, and/or air expulsion additives.
Component (C): Metallic Detergents
[0037] Certain metallic detergents may optionally be included in the additive package and
transmission fluids 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, (5) 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.
[0038] 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.,
US 6,482,778.
[0039] 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.
[0040] The term "overbased" in connection with metallic detergents is used to designate
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 solution 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 useful 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.
[0041] Examples of suitable metal-containing detergents include, but are not limited to,
neutral and overbased salts such as a 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 sulfurized lithium
phenate, a magnesium sulfonate, a magnesium carboxylate, a magnesium salicylate, a
magnesium phenate, a sulfurized 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 phosphosulfurized
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 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.
[0042] 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.
[0043] 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.
Pat. 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.
[0044] 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. Pat. Nos. 3,480,548; 3,679,584; 3,829,381; 3,909,691; 4,965,003; and 4,965,004.
[0045] 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 0.2 wt.% in the finished fluid, or as a further example, from about
0.05 to about 0.1 wt.% in the finished fluid.
Component (D): Dispersant
[0046] Component (D) comprises at least one oil-soluble dispersant. Suitable 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.
[0047] Hydrocarbyl substituted acylating agents are made by reacting a polyalkyl olefin
or chlorinated polyalkyl olefin of appropriate molecular weight with maleic anhydride.
Similar carboxylic reactants can be used to make the acylating agents. Such reactants
may include, but are not limited to, maleic acid, fumaric 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.
[0048] 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.
[0049] The mole ratio of maleic 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 500 to about
7000, or as a further example, about 800 to about 3000 or higher and the ethylene-alpha-olefin
copolymers, the maleic anhydride may be used in stoichiometric excess, e.g. about
1.1 to about 3 moles maleic anhydride per mole of olefin. The unreacted maleic anhydride
can be vaporized from the resultant reaction mixture.
[0050] The polyalkyl 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.
[0051] 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.
[0052] 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 alkenyl 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 maleic anhydride to about
180°-220°C. The polyolefin may be a polymer or copolymer of a lower monoolefin 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).
[0053] 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.
A few representative examples are: N-methyl-propanediamine, N-dodecylpropanediamine,
N-aminopropyl-piperazine, ethanolamine, N-ethanol-ethylenediamine, and the like.
[0054] Suitable amines may include polyalkylene polyamines, such as propylene diamine, dipropylene
triamine, di-(1,2-butylene)triamine, and tetra-(1,2-propylene)pentamine. A further
example includes the polyethylene polyamines which can be depicted by the formula
H
2N(CH
2CH
2NH)
nH, wherein n may be an integer from about one to about ten. 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 polyethylene polyamines have
a primary amine group at each end so they may form mono-alkenylsuccinimides and bis-alkenylsuccinimides.
Commercially available polyethylene 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.
[0055] 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 hydrocarbon substituted 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., maleic anhydride, maleic acid, fumaric acid,
or the like, including mixtures of two or more such substances.
[0056] 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
polyamines are described in more detail in U.S. Pat. Nos. 4,863,623 and 5,075,383.
Such polyamines can provide additional benefits, such as anti-wear and antioxidancy,
to the final products.
[0057] 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. Pat. Nos. 5,634,951 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 example, these alkyl groups may be methyl and/or ethyl groups. Polyamine
reactants of this type may include dimethylaminopropylamine (DMAPA) and N-methyl piperazine.
[0058] Hydroxyamines suitable for herein include compounds, oligomers or polymers containing
at least one primary or secondary amine capable of reacting with 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-2PO or HMDA-3PO),
3-amino-1,2-propanediol, tris(hydroxymethyl)aminomethane, and 2-amino-1,3-propanediol.
[0059] 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.
[0060] The foregoing dispersant may also be a post-treated dispersant made, for example,
by treating the dispersant with maleic anhydride and boric acid as described, for
example, in U.S. Patent No. 5,789,353 to Scattergood, or by treating the dispersant
with nonylphenol, formaldehyde and glycolic acid as described, for example, in U.S.
Patent No. 5,137,980 to DeGonia, et al.
[0061] 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.
[0062] 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
source generally contains, for example, at least about 40 carbon atoms, and 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 raffinate I stream.
[0063] 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.
[0064] 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. Pat. 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 raffinate I stream as described above. PIB-amines
and PIB-polyamines may also be used.
[0065] 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; 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.
[0066] 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. Pat. 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.
[0067] 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 an even further example, the borated dispersant may include from
about 0.25 to about 0.7 wt.% of boron. As a further example, the borated dispersant
may include from about 0.35 to about 0.7 wt.% of boron. 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.
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.
[0068] 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 seals,
for example.
[0069] A dispersant may be present in the power transmission fluid in an amount of about
0.1 wt.% to about 10 wt.%. Further, the power transmission fluid may include from
about 2 wt.% to about 7 wt.% of the borated dispersant. Further, the power transmission
fluid may include from about 3 wt.% to about 5 wt.% of the borated dispersant. Further,
the power transmission fluid may include an amount of the borated dispersant sufficient
to provide up to 1900 parts per million (ppm) by weight of boron in the finished fluid,
such as for example, from about 50 to about 500 ppm by weight of boron in the finished
fluid.
Component (E): Antiwear Agents
[0070] In addition to the extreme pressure and antiwear enhancements achieved using Components
(A) and (B) in transmission fluids at the relatively high rates indicated herein,
the antiwear characteristics of the finished fluid also optionally may be further
modified by addition of 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
phosphite, a trihydrocarbyl phosphite, 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
phosphite and an amine salt of sulfurized dibutyl hydrogen phosphite.
[0071] 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
million by weight of phosphorus in the power transmission fluid.
[0072] The power transmission fluid may include from about 0.01 wt.% to about 1.0 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
0.1 wt.% to about 0.2 wt.% of a dibutyl hydrogen phosphite or 0.3 wt.% to about 0.4
wt.% an amine salt of a sulfurized dibutyl hydrogen phosphate.
Component (F): Friction Modifiers
[0073] Friction modifiers are 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 (µ-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).
[0074] 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 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.
[0075] The succinimide may include the reaction product of a succinic acid or 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
12 to about C
36 aliphatic hydrocarbyl succinimide. As a further example, the succinimide may include
an about C
16 to about C
28 aliphatic hydrocarbyl succinimide. As an even further example, the succinimide may
include an about C
18 to about C
24 aliphatic hydrocarbyl succinimide.
[0076] 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, no non-metallic friction modifier other than the succinimide disclosed
herein is included.
[0077] The succinimide may include one or more of a compound having the following structure:
wherein Z may have the structure:
wherein either R
1 or R
2 may be hydrogen, but not both, and wherein R
1 and R
2 may be independently straight or branched chain hydrocarbon groups containing from
about 1 to about 34 carbon atoms such that the total number of carbon atoms in R
1 and R
2 is from about 11 to about 35; X is an amino group derived from ammonia or a primary
amine; and
wherein, in addition to or in the alternative, the parent succinic anhydride may be
formed by reacting maleic 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 α-olefin or mixture thereof to obtain a mixture
of internal olefins. The reaction may involve an equimolar amount of ammonia and may
be carried out at elevated temperatures with the removal of water.
[0078] One group of 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.
[0079] An example of a suitable 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 group
free of acetylenic 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.
Pat. Nos. 5,372,735 and 5,441,656.
[0080] Another friction modifier system is 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. Pat. No. 5,344,579.
[0081] Another suitable group of friction modifiers include polyolesters, for example, glycerol
monooleate (GMO), glycerol monolaurate (GML), and the like.
[0082] Generally speaking, the compositions may contain up to about 1.25 wt.%, or, as a
further example, from about 0.05 to about 1 wt.% of one or more friction modifiers.
Component (G): Antioxidants
[0083] 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 polyalkyl phenols, and 4,4'-thiobis(2-methyl-6-tert-butylphenol).
N,N'-di-sec-butyl-phenylenediamine, 4-isopropylaminodiphenylamine, phenyl-.alpha.-naphthyl
amine, phenyl-.alpha.-naphthyl amine, and 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 3.0 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 1.0 wt.%.
Component (H): Anti-Rust agents
[0084] Rust or corrosion inhibitors are another type of inhibitor additive for use in embodiments
of the present disclosure. 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, tetradecenylsuccinic
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 corrosion inhibitor in the transmission fluid
formulations described herein may range from about 0.01 to about 2.0 wt.% based on
the total weight of the formulation.
Component (I): Copper Corrosion Inhibitors
[0085] In some embodiments, copper corrosion inhibitors may constitute another class of
additives suitable for inclusion in the compositions. Such compounds include thiazoles,
triazoles, and thiadiazoles. Examples of such compounds include benzotriazole, tolyltriazole,
octyltriazole, decyltriazole, dodecyltriazole, 2-mercapto benzothiazole, 2,5-dimercapto-1,3,4-thiadiazole,
2-mercapto-5-hydrocarbylthio-1,3,4-thiadiazoles, 2-mercapto-5- 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. Pat. 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.
Component (J): Viscosity Index Improvers
[0086] Viscosity index improvers for use in the above described fluid transmission and gear
lubricant compositions may be selected from polyisoalkylene compounds, polymethacrylate
compounds, and any conventional viscosity index improvers. 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.
[0087] Suitable viscosity index improvers may include styrene-maleic 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.
Component (K): Antifoam agents
[0088] In some embodiments, a foam inhibitor may form 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 0.01 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.%.
Component (L): Seal Swell agents
[0089] The seal swell agent used in the transmission fluid compositions described herein
is selected from oil-soluble diesters, oil-soluble sulfones, and mixtures thereof.
Generally speaking the most suitable diesters include the adipates, azelates, and
sebacates of C
8-C
13 alkanols (or mixtures thereof), and the phthalates of C
4-C
13 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.
[0090] Other esters which may give generally equivalent performance are polyol esters. Suitable
sulfone seal swell agents are described in U.S. Pat. Nos. 3,974,081 and 4,029,587.
Typically these products are employed at levels in the range of about 0.25 wt.% to
about 5 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 wt.%.
[0091] 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 amounts in the range of from about 1 to about 15 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 wt.%. Generally speaking, the higher the molecular
weight of the adipate, sebacate or phthalate, the higher should be the treat rate
within the foregoing ranges.
Component (M): Dye:
[0092] A colorant may be added to the fluid to give it 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.
Component (N): Diluent
[0093] If the additives are provided in an additive package concentrate, a suitable carrier
diluent is added to ease blending, solubilizing, and transporting the additive package.
The diluent oil needs to be compatible with the base oil and the additive package.
In one embodiment, the diluent is present in the concentrate in an amount of between
about 5 to about 20%, although it can vary widely with application. Generally speaking,
less diluent is preferable as it lowers transportation costs and treat rates.
[0094] 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.
Base Oil
[0095] Transmission fluids of the present invention typically (but not necessarily always)
are formulated with a major amount of a base oil and a minor amount of the additive
package which includes the extreme-pressure/antiwear enhancing combination of sulfurized
fatty oil and dialkyl thiadiazole at the prescribed addition levels. In one embodiment,
a power transmission fluid composition is formulated to contain a major amount of
base oil and about 10 wt.% to about 20 wt.% of an additive composition containing
the sulfurized fatty oil and dialkyl thiadiazole in the respective levels prescribed
herein.
[0096] 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.
[0097] Synthetic oils include hydrocarbon oils such as polymerized and interpolymerized
olefins (e.g., polybutylenes, polypropylenes, propylene isobutylene copolymers, etc.);
polyalphaolefins such as poly(1-hexenes), poly-(1-octenes), poly(1-decenes), etc.
and mixtures thereof; alkylbenzenes (e.g., dodecylbenzenes, tetradecylbenzenes, di-nonylbenzenes,
di-(2-ethylhexyl)benzenes, etc.); polyphenyls (e.g., biphenyls, terphenyl, alkylated
polyphenyls, etc.); alkylated diphenyl ethers and alkylated diphenyl sulfides and
the derivatives, analogs and homologs thereof and the like.
[0098] 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 C
3-8 fatty acid esters, or the C
13 Oxo acid diester of tetraethylene glycol.
[0099] 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, maleic 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.
[0100] Esters useful as synthetic oils also include those made from C
5 to C
12 monocarboxylic acids and polyols and polyol ethers such as neopentyl glycol, trimethylol
propane, pentaerythritol, dipentaerythritol, tripentaerythritol, etc.
[0101] 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 American Petroleum Institute (API) Base Oil Interchangeability Guidelines.
[0102] Such base oil groups are as follows:
Base Oil Group1 |
Sulfur (wt.%) |
|
Saturates (wt.%) |
Viscosity 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 |
1Groups I-III are mineral oil base stocks. |
[0103] 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
with the foregoing poly-alpha-olefins may be used.
[0104] The base oil may be an oil derived from Fischer-Tropsch synthesized hydrocarbons.
Fischer-Tropsch synthesized hydrocarbons are made from synthesis gas containing H
2 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. Pat. Nos. 6,103,099 or 6,180,575;
hydrocracked and hydroisomerized using processes disclosed in U.S. Pat. Nos. 4,943,672
or 6,096,940; dewaxed using processes disclosed in U.S. Pat. No. 5,882,505; or hydroisomerized
and dewaxed using processes disclosed in U.S. Pat. Nos. 6,013,171; 6,080,301; or 6,165,949.
[0105] Unrefined, refined and rerefined 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 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.
[0106] In selecting any of the foregoing optional additives, it is important to ensure that
the selected component(s) is/are soluble or stably dispersible in the additive package
and finished 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, viscosity and/or shear stability
properties, needed or desired, as applicable, in the overall finished composition.
[0107] In general, the ancillary additive components are employed in the oils 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.
[0108] However, generally speaking, the following generally concentrations (weight percent
unless otherwise indicated) of the additional components in the base fluids are illustrative:
Optional Additive Component |
Range |
C |
0.00-1.00 |
D |
1.00-15.00 |
E |
0.00-1.00 |
F |
0.01-1.25 |
G |
0.10-5.00 |
H |
0.01-0.30 |
I |
0.00-0.50 |
J |
1.0-25.0 |
K |
0.005-0.05 |
L |
1.0-30.0 |
M |
1-400 ppm |
N |
1.0-25.0 (in concentrate balance) |
[0109] 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.
[0110] 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
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.
[0111] 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 lubricant is used that does
not possess sufficient extreme pressure protection characteristics. However, power
transmission fluid compositions as described herein have greatly improved extreme
pressure 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. They may be used
in axles, transfer cases, and the like. Further, they may also be useful in metalworking
applications.
EXAMPLES
[0112] 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.
[0113] The following tables illustrate the steel-on-steel extreme pressure characteristics
of transmission fluids as described herein evaluated using a Falex extreme pressure
(EP) test according to ASTM D 3233. The Falex EP test measures the load carrying ability
of an oil. According to the test, a 1/4 inch (6.35 mm) diameter test journal or pin
is rotated at 290 rpm between two Vee Blocks immersed in the oil preheated to 51.7°C.
Procedure A employs a constant increase in load applied by an automatic ratchet until
failure as indicated by seizure of the test coupon or rapid loss of load caused by
excessive wear. Procedure B employs load increments of 250 lbs with running for 1
minute at each increment until failure. The standard test pin is AISI 3135 Steel,
HRB 87 and the standard Vee Blocks are AISI C-1137 Steel, HRC 20 to 24. Procedure
B was used to determine the failure load of test fluid for purposes of the tests run
and described below. The failure loads reported below are averages of two experiments
run on a given test fluid back-to-back. The various transmission fluid compositions
were tested at 100°C and 150°C. A separate sample of each test fluid was used at each
of these test temperatures. Higher loads to seizure signify better extreme pressure
(EP) performance. The baseline fluid for these tests contained the following components:
(a) Metallic detergents- from about 0.00 to about 0.1 wt.%
(b) Friction modifiers ― from about 0.01 to about 0.5 wt.%
(c) Anti-oxidants ― from about 0.01 to about 2.0 wt.%
(d) Anti-rust agents ― from about 0.01 to about 0.3 wt.%
(e) Dispersants ― from about 0.5 to about 10.0 wt.%
(f) Anti-foam agents ― from about 0.0001 to about 0.5 wt.%
(g) Base Oil (mineral or synthetic) ― balance of baseline fluid
[0114] A series of test fluids was prepared by dissolving a dialkyl thiadiazole and one
of various sulfurized fatty oils in different respective amounts in baseline fluid.
The additive package is dissolved in the baseline fluid at a total concentration of
14-17%.
[0115] The dialkyl thiadiazole used was a 2,5-bis(hydrocarbyldithio)-1,3,4-thiadiazole.
The sulfurized fatty oils used were SFO1, SFO2, SFO3, and SFO4. All of the test fluids
were fully-formulated ATFs. They are designated as Examples (Ex.) 1-7 and Comparative
Examples (CEx.) 1-5 below in Table 1. The respective addition rates of the sulfurized
fatty oil and dialkyl thiadiazole in the test fluids, as well as the performance of
these test fluids in the Falex EP tests is indicated in Table 1.
[0116] These experimental results show that that test fluids containing high concentrations
of both sulfurized fatty oils and dialkyl perform very well in the Falex EP test.
Specifically, the transmission fluids tested that contained sufficient 2,5-dihydrocarbylmercapto-1,3,4-thiadiazole
to contribute at least 600 ppm S and sufficient sulfurized fatty oil to contribute
at least 1,000 ppm S exhibited a failure load performance of at least about 1750 pounds
at both 100°C and 150°C (see Examples 1, 2, 4, 6, and 7). Examples 3 and 5 had failure
loads that were both somewhat below 1750 pounds, but they were nonetheless consistently
high in value. Comparative Examples 1-5, in which the transmission fluids tested contained
either insufficient 2,5-dihydrocarbylmercapto-1,3,4-thiadiazole to contribute at least
600 ppm S or insufficient sulfurized fatty oil to contribute at least 1,000 ppm S,
exhibited a failure load performance below 1750 pounds at 100°C and/or 150°C. At numerous
places throughout this specification, reference has been made to a number of U.S.
Patents. All such cited documents are expressly incorporated in full into this disclosure
as if fully set forth herein.
[0117] 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.
[0118] 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.
1. A fluid composition, including:
(1) a major amount of a base oil, and
(2) a minor amount of an additive including:
(A) sulfurized fatty oil in an amount sufficient to provide at least 1,000 ppm sulfur
to the fluid composition, and
(B) dialkyl thiadiazole in an amount sufficient to provide at least 500 ppm sulfur
to the fluid composition.
2. The fluid composition of claim 1, which provides a transmission fluid exhibiting failure
loads which equal or exceed 1750 pounds at 100°C and 150°C, respectively, as measured
according to a Falex EP test of ASTM D-3233.
3. The fluid composition of any one of claims 1-2, wherein component (A) is present in
an amount sufficient to provide 1,000 ppm to 2,500 ppm sulfur to the fluid composition,
and component (B) is present in an amount sufficient to provide 500 ppm to 1,800 ppm
sulfur to the fluid composition.
4. The fluid composition of any one of claims 1-2, wherein component (A) is present in
an amount sufficient to provide 1,300 ppm to 2,100 ppm sulfur to the fluid composition,
and component (B) is present in an amount sufficient to provide 550 ppm to 1,500 ppm
sulfur to the fluid composition.
5. The fluid composition of any one of claims 1-4 wherein combined sulfur added to the
fluid composition by the sulfurized fatty oil and dialkyl thiadiazole is least 1,500
ppm.
6. The fluid composition of any one of claims 1-4, wherein combined sulfur added to the
fluid composition by the sulfurized fatty oil and dialkyl thiadiazole is least 2,500
ppm.
7. The fluid composition of any one of claims 1-4, wherein combined sulfur added to the
fluid composition by the sulfurized fatty oil and dialkyl thiadiazole is least 3,000
ppm.
8. The fluid composition of any one of claims 1-2, wherein component (A) is present in
an amount of at least 0.5 wt.%, and component (B) is present in an amount of at least
0.15 wt.%, based on the total weight of the fluid composition.
9. The fluid composition of any one of claims 1-2, wherein component (A) is present in
an amount of 0.5 wt.% to 5.0 wt.%, and component (B) is present in an amount of 0.15
wt.% to 3.0 wt.%, based on the total weight of the fluid composition.
10. The fluid composition of any one of claims 1-2, wherein component (A) is present in
an amount of 0.7 wt.% to 3.0 wt.%, and component (B) is present in an amount an amount
of 0.15 wt.% to 1.0 wt.%, based on the total weight of the fluid composition.
11. The fluid composition of any one of claims 1-2, wherein component (A) is present in
an amount of 0.73 wt.% to 3.0 wt.%, and component (B) is present in an amount of 0.3
wt.% to 1.0 wt.%, based on the total weight of the fluid composition.
12. The fluid composition of any one of claims 1-2, wherein component (A) is present in
an amount of 0.75 wt.% to 3.0 wt.%, and component (B) is present in an amount of 0.35
wt.% to 1.0 wt.%, based on the total weight of the fluid composition.
13. The fluid composition of any one of claims 1-2, wherein the additive composition is
present in an amount of 10 wt.% to 20 wt.%, based on the total weight of the fluid
composition.
14. The fluid composition of any one of claims 1-13, wherein component (A) is sulfurized
transesterified triglyceride.
15. The fluid composition of any one of claims 1-13, wherein component (A) is selected
from the group consisting of a sulfurized fat, a sulfurized fatty acid, a sulfurized
fatty acid ester, and a sulfurized fatty olefin.
16. The fluid composition of any one of claims 1-13, wherein component (A) is 2,5-bis(hydrocarbyldithio)-1,3,4-thiadiazole
or a derivative thereof.
17. The fluid composition of any one of claims 1-16, wherein component (B) is a compound
of the formula:
wherein R
1 and R
2 may be the same or different hydrocarbyl groups, and x any y independently may be
integers from 0 to 8, and the sum of x and y being at least 1.
18. The fluid composition of claim 17, wherein R1 and R2 are the same or different hydrocarbyl group having from 6 to 18 carbon atoms.
19. The fluid composition of claim 17, wherein R1 and R2 may be the same or different hydrocarbyl group having 8 to 12 carbon atoms, and x
and y each are 1.
20. The fluid composition of any one of claims 1-19, wherein the base oil includes one
or more of a natural oil, a mixture of natural oils, a synthetic oil, a mixture of
synthetic oils, a mixture of natural and synthetic oils, and a base oil derived from
a Fischer-Tropsch or gas-to-liquid process.
21. The fluid composition of any one of claims 1-20, wherein the base oil has a kinematic
viscosity of from 2 centistokes to 10 centistokes at 100° C.
22. The fluid composition of any one of claims 1-21, wherein the additive composition
further includes one or more of a detergent, a dispersant, a friction modifier, an
antioxidant, an antiwear agent, an antifoam agent, a viscosity index improver, a copper
corrosion inhibitor, an anti-rust additive, a seal swell agent, a metal deactivator,
and an air expulsion additive.
23. The fluid composition of any one of claims 1-22, wherein the fluid is suitable for
use in 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.
24. The fluid composition of any one of claims 1-22, wherein the fluid is suitable for
use in a belt, chain, or disk-type continuously variable transmission, a 4-, 5-, 6-,
or 7-speed automatic transmission, a manual transmission, an automated manual transmission,
or a dual clutch transmission.
25. The fluid composition of any one of claims 1-22, wherein the fluid is suitable for
use in an industrial gear or an automotive gear.
26. A transmission containing the fluid composition of any one of claims 1-22.
27. The transmission of claim 26, wherein the transmission is a continuously variable
transmission.
28. The transmission of claim 26, wherein the transmission is a dual clutch transmission.
29. The transmission of claim 26, wherein the transmission is an automatic transmission.
30. The transmission of claim 26, wherein the transmission is a manual transmission.
31. A vehicle including an engine and a transmission, the transmission including the transmission
fluid of any one of claims 26-30.
32. A vehicle including a differential, the differential including a lubricant containing
the fluid composition of any one of claims 1-22.
33. A method for improving extreme pressure and/or wear performance in power transmitting
apparatus including:
1) adding a fluid as claimed in any one of claims 1-22, to a power transmitting apparatus;
and
2) operating the fluid in the power transmitting apparatus, wherein the extreme pressure
and/or wear performance is improved relative to the extreme pressure and/or wear performance
of a transmission without said fluid.
34. The method of claim 33, wherein the power transmitting apparatus includes a transmission.
35. The method of claim 33, wherein the power transmitting apparatus includes an industrial
gear or an automotive gear.