Note: Descriptions are shown in the official language in which they were submitted.
021987 2 5
~- w096/06903 PCT~S94/09981
DTM~P~ ,nlADIAZO~E-M~R~PTAN COUPLED COMPOUNDS
A8 MULTIFUNCTIONAL ADDITIVES FOR LUBRICANT8 AND FUELS
This invention is directed to combinations of
dimercaptothiadiazole-mercaptan coupled dithio compounds
with amines which have proven to be highly effective
multifunctional antiwear/extreme pressure additives for
lubricants and fuels.
Dimercaptothiadiazole derivatives, such as
2,5-dimercapto-1,3,4-thiadiazole, disodium
2,5-dimercaptothiadiazole and 2, 5-bis(t-nonyl-dithio)
thiadiazole, are well known for their antioxidancy,
anticorrosion, and metal passivation properties in a
vdriety of lubricant applications, as disclosed in U.S.
Patent Nos. 4,661,273, 4,678,592 and 4,584,114.
Furthermore, U. S. 5,186,850 discloses that the
incorporation of the heterocyclic dimercaptothiadiazole
functionality into succinimide structures provides ashless
dispersants with multifunctional antiwear, antioxidant and
corrosion inhibitor properties in lubricant compositions.
Additionally, various reaction products of mercapto- and
dimercaptothiadiazoles have been known to possess extreme
pressure/antiwear properties, in a variety of lubricant
formulations, as exemplified in U.S. Pat. No. 4,661,273;
4,382,869; and 4,678,592.
The use of amines in lubricants and the detergent
industry has been well known for their alkalinity, surface
activity, and neutralization capability. Amine phosphate
is one class of additivies used extensively in industrial
oils, and polyamine-derived succinimides are key components
in ashless dispersants of engine oils.
Reaction products of dimercaptothiadiazole derived
alcohols and alkenyl succininc anhydrides and their
subsequent amine reaction products have been found to be
effective antiwear/antioxidant additives for lubricants;
see U.S. 4,908,144. U.S. 5,188,746 discloses antiwear/
antioxidant additives for lubricants based on
021 987 2 9
W096/06903 2 PCT~S~ 31
dimercaptothiadiazole derivatives of acrylate and
methacrylate polymers and amine reaction products thereof.
It has now been found that the use of these
combinations of thiadiazole-derived dithio additives with
amine derivatives, in accordance with the present
invention, provide exceptional antiwear/EP activity with
significantly enhanced metal passivating/corrosion
inhibiting properties for lubricants and fuels.
Lubricant and fuel compositions in accordance with the
invention containing small additive concentration of a
combination of a dimercaptothiadiazole-mercaptan coupled
compound with an amine product possess excellent antiwear
properties coupled with good extreme pressure activities.
Additional antioxidation, cleanliness, antifatigue, high
temperature stabilizing, and friction modifying properties
are likely. Both the thiadiazole-dithio moiety and the
amine/ammonium salt moiety are believed to provide the
basis for the synergistic antiwear and EP property of these
novel additives.
All of these beneficial properties are believed to be
enhanced as a result of this novel internal synergism.
This unique internal synergism concept is believed to be
applicable to similar structures containing (a) thiadiazole
groups, (b) dithio linking groups, (c) amine groups within
the same component. The products of this invention show
good stability and compatibility when used in the presence
of other commonly used additives in fuel or lubricant
compositions.
These remarkable benefits are also expected for a
variety of synthetic and mineral oil based lubricants and
fuels particularly light distillate fuels containing these
additives. The compositions of matter and the lubricant
and fuel compositions are believed to the novel. To the
best of our knowledge, these compositions have not been
previously used as antiwear/extreme pressure additives in
lubricating oils, greases, or fuel applications.
~ ~ 7 9 8 7 2 5
~ W096/06903 pcT~ss~ 3
-3-
More specifically this invention is directed to
improved lubricant or fuel compositions comprising a major
proportion of an oil of lubricating viscosity or a grease
prepared therefrom, or a major proportion of a liquid
hydrocarbyl or hydrocarboxy fuel and a minor proportion of
a multifunctional antiwear/extreme pressure additive
product of reaction consisting of combinations of
dimercaptothiadiazole-mercaptan coupled dithio compounds
with hydrocarbyl amines.
10 PreParation
2,5-dimercapto-1,3,4-thiadiazole (DMTD), made by the
reaction of hydrazine with carbon disulfide, oxidatively
coupled with alkyl mercaptans, such as nonyl, to form
thiadiazole-derived dithio compounds (Structure A). These
dithio adducts were then blended with various amines to
form a new group of additive blends.
~J ~
S~S~S~t~
(Structure A)
However, applicants do not wish to be bound by a particular
structure(s) or formula for the additive reaction products
in accordance with the invention [Structure(s) B] i.e., the
combination of the dithio adducts blended with the various
amines.
The mercaptothiadiazoles may be prepared as above or
made in any convenient manner or obtained as an article of
commerce. Any suitable mercaptothiadiazole such as 2,5-
dimercapto-1,3,4-thiadiazole; 3,5-dimercapto-1,2,4-
thiadiazole; 4,5-dimercapto-1,2,5-thiadiazole; etc. can be
used. Accordingly, the hydrocarbyl groups need not be
alkyl or limited to C9H19 but may be R as in the below
generalized structure:
W096,06903 0 2 ~ 9 8 7 2 5 PCT~S94/09981
~J
S
(Structure B)
where R and R1 can be the same or different and are
hydrogen or C1 to about C30 hydrocarbyl selected from alkyl,
aryl, aralkyl, alkaryl and may optionally contain
additional O, S, or N or mixtures thereof. Preferably R is
CnH2n~l, there n is 1 to about 30.
Mercaptobenzothiazoles such as 6,7-dimercaptobenzo-
2,1,3-thiadiazole are also believed to be suitable.
Generally, the amines used in this invention are
aliphatic and can be primary, secondary, or tertiary and
preferably alkylamines or arylamines.
Non-limiting examples of primary amines are
methylamine; ethylamine; n-propylamine; isopropylamine; n-
butylamine; dodecylamine; triacontylamine; allylamine; 2-
propynlamine; cyclohexylamine, propargylamine;
isobutylamine; sec-butylamine; 2-ethylhexylamine;
cyclopropylmethylamine; t-butylamine; 1,1-dimethyl-2-
propynlamine; l,l-diethyl-2-propynylamine, 1-
ethynylcyclohexylamine and benzylamine.
Non-limiting examples of secondary amines-are
dimethylamine, diethylamine, dibutylamine, diotylamine,
ditetradecylamine, diallylamine, di-2-hexenylamine,
dicyclohexylamine, methylethylamine, methyl
cyclohexylamine, diisopropylamine, diisopentylamine, ethyl
cyclohexylamine, (3-amine-propyl)alkenylamine wherein the
alkenyl group has 16 to 18 carbon atoms; (3-aminopropyl)
alkenylamine wherein the alkenyl group has 18, 20, and 22
carbon atoms: and dihydrogenated tallow amine (e.g. Armeen
2HT).
Q~872s
wosc/069v3 5 PCT~S94/osg8
Non-limiting examples of tertiary amines are
trimethyamine, dimethyl ethylamine, triethylamine,
tributylamine, trioctylamine, triallylamine,
triisopentylamine, tricyclohexylamine, dimenthyl
octylamine, n-hexadecyldimethylamine, (e.g. Armeen DM16D),
n-octadecyl-dimethylamine (e.g. Armeen DM18D), methyl di-
hydrogenated tallowamine (e.g. Armeen M2HT), and methyl
dicocoamine (e.g. Armeen M2C).
Non-limiting examples of arylamines are aniline 2-
chloroaniline; 2-chloroaniline; 4-chloroaniline; 2-methyl-
4-chloroaniline; 2,4-dichloroaniline; 3,4-dichloroaniline;
2,5-dichloro-4-nitroaniline; m-tri-fluoromethylaniline;
isopropulaniline; p-methoxyaniline; N-methoxymethyl-2,6-
diethylaniline; a-naphthylamine; N-sec-butl-4-t-butyl-2,6-
dinitroaniline; 3-amino-2,5-dichlorobenzoic acid; N,N-
dipropyl,a,a,a-trifluoro-2,6-dinitro-p-toluidine; 4-bromo-
3-chloroaniline; 4(4 -chlorophenoxy) aniline; N3, N3-
diethyl-2,4-dinitro-6-trifluoromethyl-m-phenylenediamine;
p-dimethylaminoanline; diphenylamine; p-bromoaniline; m-
aminiphenyl-t-butylcarbamate; o-phenylenediamine; m-
phenylenediamine; 4-dimethylamino-3,5-dimethylphenol; 4-
(methylsulfonyl)-2,6-dinitro-N,N-dipropylaniline; 3,5-
dinitro-N,N-dipropylsulfanilamide; N-sec-butyl-4-t-butyl-
2,6-dinitroaniline; m-toluisine; p-toluidine; m-t-
butylaniline; o-anisidine; p-anisidine; dimethylaniline; o-
nitroaniline; p-nitroaniline; and 4,4'-oxydianiline.
Non-limiting examples of heterocyclic amines are 3-
amino-1,2,4-triazole; 2-chloro-4-ehtylamino-6-
isopropylamino-s-triazine; pyridine; piperidine;
piperazinei morphiline; 4,4'-dipyridyl; 8-ydroxyquinoline;
; 4-amino-6-t-butyl-3-(methykthio)-1,2,4-triazine-5(4H)-one;
6-ethoxy-1,2-dihydro-2,2,,4-trimethylquinoline; indole;
hexahydro-lH-azepine; 4-amino-5-chloro-2-pheyl-3(2H)-
pyridazinone; pyrrole; imidazolidine; isoquinoline; 2,4-
lutidine; 2-methyl-5-ethylpyridine; 2-dimethyl
W096l06903 ~ 2 1 9 8 7 2 5 -6- PCT~S~ 59~1
aminopyridine; a-picoline; B-picoline; y-picoline;
quinoline; and 4,4'-dipyridine.
Non limiting examples of other salt forming amino
compounds contemplated are 2-chloroethyl dimethylamine,
diethanilaminel guanidine; dodecylguanidine; 3-(4-
chlorophenyl)l-,1-dimethylurea, 3-(3,4-dichlorophenyl)-1,1-
dimethylurea, Fenuron; Tandex; B-alanine; methyl glycine;
glycinamide; aminoacetonitrile; aminoethanthiol;
aminoacetic acid; diethyl ethanolamine; diethylenetriamine;
isopropanolamine; diisopropanolaminel triisopropanolamine;
ethylenediamine; hexamethylenetetramine; hydrazine;
phenothiazine; sulfanilic acid; tetraethylenepentamine;
thiourea; urea; triethanolamine; triethylenetetramine;
diethanol soyaamine (e.g. Ethomeen S-12) and5 didecaoxyethylene soyaamine (e.g. Ethomeen S-20).
Examples of highly suitable amines are:
a) cyclic amines: dicyclohexylamine, 1,4-
diaminocyclohexane, piperidine, hexamethyleneimine, etc.;
b) heterocyclic amines: morpholine, aminopropyl0 morpholine (APM), aminoethyl piperazine (AEP);
c) etheramines: C6 to C13 alkyloxypropylamines (Exxon
and Sherex), polyoxyalkylene amines (Texaco Jeffamine);
d) diamines: Exxon etherdiamines (DA-14, DA-17),
Texaco polyoxyalkylene diamine, Akzo Duomeens (Duomeen5 C&O);
e) straight chain amines: ethylamine, propylamine,
butylamine, pentylamine, hexylamine, dioctylamine,
dicocoamine, etc.;
f) branched chain amines: 2-ethylhexylamine,
isopropylamine, isobutylamine, diisobutylamine, bis(2-
ethylhexyl)amine, tert-alkyl amine(C18-C22), dicocoalkyl-
methylamine.
An excess of one reagent or another can be used.
Molar quantities, less than molar quantities, or more than
molar quantities of either amines or dithio-adducts can be
used.
a2~ss;72s
~~ W096/06903 7 PCT~S94109981
Conditions for the above reactions may vary widely
depending upon specific reeactants, the presence or absence
of a solvent and the like. Any suitable set of reaction
conditions known to the art may be used. Generally
stoichiometric or equimolar ratios of reactnats are used.
However, more than molar or less than molar amounts may be
used. In any event, reaction conditions are not viewed as
critical. Generally speaking, the reaction temperature may
vary from ambient to about 250 C or reflux, the pressure
may be autogenous or vary from ambient to about lO0 psi
with reaction times varying from about one hour to about 48
hours or more.
Clearly the use of additive concentrations of these
dithio adducts coupled with various amines provide
exceptional antiwear, load-carrying activity and corrosion
inhibiting properties, etc. when incorporated into fuel and
lubricant compositions.
The additives embodied herein are utilized in
lubricating oil or grease compositions in an amount which
imparts significant antioxidant, load-carrying and
corrosions inhibiting characteristics to oil or grease as
well as reducing the friction of engines operating with the
oil in its crankcase. Concentrations of O.OOl to lO wt. %
based on the total weight of the composition can be used.
Preferably, the concentration is from O.l to 3 wt. %. It
is expected that these materials would also be suitable for
use in liquid hydrocarbyl or alcoholic or mixed
hydrocarbyl/alcoholic fuel compositions. They are generally
utilized in amounts varying from 50 to 500 pounds per lO00
barrels of fuel.
The additives have the ability to improve the antiwear
characteristics and friction reducing characteristics of
various oleagenous materials such as hydrocarbyl
lubricating media which may comprise liquid oils in the
form of either a mineral oil or a synthetic oil, or in the
W096l06903 ~ 2 ~ 9 ~ 7 2 5 -8- PCT~S94/09981
form of a grease in which the aformentioned oils are
employed as a vehicle.
In general, mineral oils, both paraffinic, naphthenic
and mixtures thereof, employed as the lubricant, or grease
vehicle, may be of any suitable lubricating viscosity
range, as for example, from 6 mm2/s at 38C (about 45 SSU
at 100F) to 1200 mm2/s at 38C (about 6000 SSU at 100F)
and preferably, from 7.5 (about 50) to 62 mm2/s (about 250
SSU) at 99C (210F). These oils which may have viscosity
indexes ranging to about 95 are preferred. The average
molecular weights of these oils may range from 250 to 800.
Where the lubricant is to be employed in the form of a
grease, the lubricating oil is generally employed in an
amount sufficient to balance the total grease composition,
after accounting for the desired quantity of the thickening
agent, and other additive components to be included in the
grease formulation.
A wide variety of materials may be employed as
thickening or gelling agents. These may include any of the
conventional metal salts or soaps, which are dispersed in
the lubricating vehicle in grease-forming quantitiès in an
amount to impart to the resulting grease composition the
desired consistency. Other thickening agents that may be
employed in the grease formulation may comprise the non-
soap thickeners, such as surface-modified clays and
silicas, aryl ureas, calcium complexes and similar
materials. In general, grease thickeners may be employed
which do not melt and dissolve when used at the required
temperature within a particular e~vironment; however, in
all other respects, any materials which is normally
employed for thickening or gelling hydrocarbon fluids for
foaming grease can be used in preparing grease in
accordance with the present invention.
In instances where synthetic oils, or synthetic oils
employed as the lubricant or wehicle for the grease, are
desired in preference to mineral oils, or in combination
~2~ 9~25
W096/06903 9 PCT~S94/093~1
therewith, various compounds of this type may be
successfully utilized. Typical synthetic oils include, but
are not limited to, polyisobutylene, polybutenes,
hydrogenated polydecenes, polypropylene glycol,
polyethylene glycol, trimethylolpropane esters, neopentyl
and pentaerythritol esters, di(2-ethylhexyl) sebacate,
di(2-ethylhexyl) adipate, dibutyl phthalate, fluorocarbons,
silicate esters, silanes, esters of phosphorus-containing
acids, liquid ureas, ferrocene derivatives, hydrogenated
synthetic oils, chain-type polyphenyls, siloxanes and
silicones (polysiloxanes), alkyl-substituted diphenyl
ethers typified by a butyl-substituted bis(p-phenoxy
phenyl) ether, phenoxy phenylethers.
It is to be understood, however, that the compositions
comtemplated herein can also contain other materials. For
example, corrosion inhibitors, extreme pressure agents and
the like can be used as exemplified respectively by
metallic phenates sulfonates, polymeric succinimides, non-
metallic or metallic phosphorodithioates and the like.
These materials do not detract from the value of the
compositions of this invention, rather the materials serve
to impart their customary properties to the particular
compositions in which they are incorporated.
The following examples are merely illustrative and are
not meant to be limitations on the scope of this invention.
EXAMPLE l
Approximately 95 gm of 2,5-bis(t-nonyl-
dithio)thiadiazole (commercially obtained from Amoco
Chemical Company under the trademark Amoco 158 or from
Mobil Chemical Company under the trademark Mobilad C-610)
and 5 gm of isodecyloxypropylamine (commercially obtained
from Sherex Chemical Company under the trademark Adogen
180) were blended together in a mixer at 80-C for two
hours. After a quick filtration, approximately 99.5 gm of
~ 2 ~ 9 ~ 7 2 S
W096/06903 10 PCT~S94/09981
yellow-brown liquid was recovered as desired blending
product.
EXAMPLE 2
Approximately 90 gm of 2,5-bis(t-nonyl-dithio)
thiadiazole and 10 gm of isodecyloxypropylamine were
blended together in a mixer at 80C for two hours. After a
quick filtration, approximately 99.2 gm of yellow-brown
liquid was recovered as desired blending product.
EXAMPLE 3
10 The reaction procedure of Example 2 was followed with
one exception: C,322 tert-alkyl primary amine (commercially
obtained from Rohm Haas Chemical Company under the
trademark Primene JM-T) was used instead of
isodecyloxypropylamine.
EXAMPLE 4
The reaction procedure of Example 1 was followed with
one exception: oleyl l,3-diaminiopropane (commercailly
obtained from AXZO Chemical Company under the trademark
Duomeen 0) was used instead of isodecyloxypropylamine.
Evaluation
The products of Exampes 2, 3 and 4 were blended into
industrial oils and evaluated for antiwear performance
using the Four-Ball test (Table 1).
~ W096/06903 Q 2 ~ 2 ~ PCT~S94/09981
Table 1
Four-Ball Wear Test
Wear Scar Diameter in mm,
30 Minute Test - 200F
60 Kg 40 Kg
Item 1500 rpm 1800 rpm
Base oil (80% solvent 2.12 0.733
parafinic bright, 20% solvent
paraffinic neutral mineral oils)
1% Mobilad C-610 0.784 0.600
1% Example 2 0.739 0.589
1% Example 3 0.772 0.636
1% Example 4 0.794 0.609
As can be seen from the above wear test results, the
product exhibits considerable antiwear activity.
The products of the examples were also blended into
fully formulated engine oils: Example 1 was evaluated for
load carrying capacity using the Four Ball EP Test (Table
2); Examples 1 and 2 were evaluated in the FZG Gear tester
(Table 3).
Table 2
Four-Ball EP Test and ASTM Copper Strip Corrosion
(EP:1760 rpm~10sec./25C; D130-6:250F/3h, Dl30-8:210F/3h/1%H20)
Plus 1% Plus 1%
25Item Base Oil* Mobilad C-610 Example 1
Last Non-seizure Load (Kg) 100 100 126
Weld Load (Kg) 200 250 250
Load Wear Index 5LWI) 41.4 46.4 53.8
Copper Strip (D130-6) 2B 2D lA
Copper Strip (D130-8) 2A 2A lA
*Base oil is a fully formulated synthetic engine oil
containing a performance additive package including
detergent, dispersant, antioxidant, corrosion inhibitor,
and a small amount of zinc dithiophosphate.
w096/06~ 2 ~ ~ ~ 7 -12- PCT~S94/09981
Table 3
Item FZG (Pass staqe)
Base Oil (fully formulated synthetic 7
oil with additive package containing
5 antioxidant, rust inhibitor, detergent,
and dispersant)
Base Oil plus 1% Example 1 10
Base oil plus 1% Example 2 12
In the Four Ball Wear Test three stationary balls are
placed in a lubricant cup and a lubricant containing the
compound to be tested is added thereto, and a fourth ball
is placed in a chuck mounted on a device which can be used
to spin the ball at known speeds and loads. The examples
were tested using half inch stainless steel balls of 52100
steel for thirty minutes under 60/40 kg load at 1500 and
1800 rpm and 93C (200-F). If additional information
concerning this test is desired consult test method ASTM
D2266 and/or U.S. Pat. No. 4,761,482.
The Copper Strip Corrosivity Test (ASTM D-130)
measures a product's propensity to corrode copper due to,
for example, contained sulfur groups. Further details may
be found in ASTM Standards on Petroleum Products and
Lubricants, published annually by the American Society for
testing Materials.
The Four-Ball EP Test (ASTM) D-2783) measures the
extreme pressure characteristics or load-carrying
properties of a lubricant by determining Load Wear Index
(LWI) and weld point. A test ball is rotated under load at
a tetrahedral position on top of three stationary balls
immersed in lubricant. Measurements of scars on the three
stationary balls are used to calculate LWI's, and the weld
is the load at which the four balls weld together in 10
seconds. The last non-seizure load is the last load at
which the measured scar diameter is not more that 5% above
the compensation line at the load. The compensation line
W096/06903 -13- PCT~S94/09981
is a logarithmic plot where the coordinates are scar
diameter in millimeters and applied load in kilograms
obtained under dynamic conditions. The higher the LWI
value the better. See U.S. 4,965,002 and ASTM D-2783.
The FZG Gear Test (DIN-51.354). In this test, dip-
lubricated gears are weighed and operated at a fixed speed
and fixed initial oil temperature (90C) in the gear oil
under test. The load on the teeth is increased in
increments. After each load stage, the weight changes are
determined and recorded. The results are reported in Table
3. The higher the Fail Stage value the better the
material. The lower the wear value the better the weight
change and/or visual condition. Further details can be
found in CEC method L-07-A-71.
As shown above, the products of this invention show
very good antiwear, extreme pressure activities as
evidenced by improving wear characteristics and scoring
load capacity from state 7 to stage 10-12 in FZG tester,
and LWI in Four Ball EP test. In addition, the product of
this invention also shows excellent corrosivity control.
The use of additive blends of bis(alkyl-
dithio)thiadiazole and amines in premium quality industrial
and engine lubricants will significantly enhance the
stability, improve load-carrying, reduce the wear, and
extend the service life. These additive blends may also
have the potential to benefit-gasoline and diesel fuels by
improving the antioxidation, antiwear, and anticorrosion
characteristics of these fuels. These novel compositions
described in this patent information are useful at low
concentrations and do not contain any potentially
undesirable metals or phosphorus. These dual functional
antiwear/EP-antioxidants can be readily commercially made.
