Note: Descriptions are shown in the official language in which they were submitted.
1038394
This invention relates to lubricant additives and to
lubricating oils and greases with improved anti-~ear and fric-
tion properties.
It is well known that certain types of lubricant
compositions, particularly oils of lubricating viscosities and
greases normally exhibit poor anti-wear properties during the
courseof their performance, as well as requiring friction modi-
f~ing improvement. In this respect, it has previously been
proposed that certain phosphorus acid esters should be used to
improve the properties of lubricants. Tri-cresyl phosphate,
for example, is well known as an anti-wear agent, particular-ly
in synthetic ester aviation fluids. The use of certain acid
phosphates in lubricants is described in U.S. Patents
3,116,284, 3,116,249, 2,72~,728, 2,801,968 and 2,285,853. The
use of certain phosphites or phosphonates, as they are various-
ly referred to, is described in U.S. Patents 3,115,466 and
2,824,131 and British Patent Specification 899,101.
The use of amine salts of certain phosphorus acids
has also previously been proposed in U.S. Patents 2,674,616,
2,874,120, 2,838,332 and 3,634,239. Canadian Patent 668,735
describes the use of imidazoline/phosphate salts.
We have now found that the imidazoline salts of
certain long chain alkyl acid phosphonates provide improve-
ments in the anti-wear and friction properties of lubricating
oils and greases.
These salts are derived from (a) an imidazoline
which is substituted by a straight chain aliphatic graup of
12 to 22 carbon atoms, and (b) a (Cl to C4 alkyl) hydrogen
(C12 to C22 straight chain alkyl) phosphonate.
The phosphonates which are reacted with the imidazo-
- 1 - q~;
~ .
.~,~ .
lQ38394
line are acid phosphonates of the formula:
OR'
R - P - O
¦ OH
where R is a long chain alkyl group of 12 to 22,- preferably
18, carbon atoms, and R' is an alkyl group (Cl-C4), preferably
methyl. The preferred acid phosphonate is methyl hydrogen
octadecylphosphonate, of the formula:
f CH3
C H P- O
OH
Acid phosphonates of this type are also referred to as alkyl
alkylphosphonic acids. See "Phosphorus and its Compounds",
vanWazer, Interscience, N.Y., Vol. I, p. 350.
The salts may be prepared by reacting the phosphon-
ate with the desired imidazoline in stoichiometric proportions.
The reaction is normally carried out at ambient temperature,
although elevated temperatures may be employed for accelera-
ting the reaction.
The imidazolines which may be used contain a long
chain (C12-C22) aliphatic group which may be saturated or
unsaturated. Such imidazolines may be prepared by the reaction
of a carboxylic acid with a polyamine which, for present
purposes, is preferably a diamine, especially ethylene diamine.
The carboxylic acid provides the desired long chain group
and thus, acids with C12-C22 aliphatic groups on the carboxyl
groups may be used to prepare the imidazoline~
-- 2 --
,.. , ~ , . .
~ J
1~38394
A particularly preferred material is the l-hydroxy-
ethyl-2-alkyl-imidazoline in which the al~yl group is derived
from oleic acid. This material can be produced by reacting
ethylene diamine with oleic acid to form the imidazoline ring
structure and then reacting the product with ethylene oxide
to produce the hydroxyethyl substituent.
N ~ CH2
-- C17H33.COoH + H2NC2H4NH2 >
7 IH2 o
Cl7H33-C~ ~CH2 + C ~CH2 N - CH2
N Cl7H33-C CH2
H N
C2H40H
Other substituted imidazolines may be made in the same way,
using other amines and acids. For example, diethylene
triamine, triethylene tetramine and tetraethylene pentamine
may be used as amines and stearic, dodecanoic, hexadecanoic,
linoleic and linolenic acids may be used as the acids.
Since the purpose of the acid is to provide the long chain
alkyl group which renders the product oil soluble, straight
chain acids containing from 12 to 22 carbon atoms in the chain
may be used. The chain may be saturated as in stearic acid
or unsaturated as in oleic acid. If the imidazoline is
produced from ethylene diamine and therefore contains an
-- 3 --
~Q38394
active hydrogen, it may be reacted with an alky}ene oxide,
preferably ethylene oxide although propylene oxide is also
contemplated, to produce a substituent hydroxyalkyl group on
¦ the imidazoline ring as shown above.
It ha~ been found that if the long chain group of
the imidazoline contains less than 12 carbon atoms, little
or no improvement in friction-modifying properties is realized.
On the other hand, if the alkyl group contains more than 22
carbon atoms, the resulting salt is found to be less soluble
in the lubricants.
Lubricant compositions containing the additives of
this invention may comprise a major amount of a lubricant
base and a minor amount of the additive salt, preferably in
an amount from 0.2 to 1.5~ by weight, and for most applica-
tions, from 0.4 to 1%, by weight, of the total weight of the
composition.
The lubricant compositions may comprise any
materials that normally exhibit insufficient anti-wear
properties or which require friction-modifying characteristics.
A field of specific applicability is the improvement of
liquid hydrocarbon oils boiling within the range from 75F
to 1000F.
-- 4 --
~,...
1038394
Mineral lubricating oils, improved in accordance with the
present invention may be of suitable lubricating viscosity
range from 45 to 6000 SSU at 100F. (5.3 to 1300 CS. at 38C)
and, prefera~ly, from 50 to 250 SSU at 210F. (7.4 to 53 CS.
at 99C) These oils may have viscosity indexes varying from
below 0 to 100 or higher. Viscosity indexes from 70 to 95 are
preferred. The average molecular weights of these oils may
r~nge from 250 to about 800. In general, the lubricant
may comprise any mineral or synthetic oil of lubricating
vi~coslty.
The salts of the present invention may be incorpor-
ated as friction modifiers or anti-wear agents in grease
compositions also. Such greases may comprise a combination
of a wide variety of lubricating vehicles and thickening or
gelling agents. Thus, greases in which the aforementioned
salts are particularly effective, may comprise any of the afore-
mentioned hydrocarbon oils of lubricating viscosity, as the
oil vehlcle, and may include mineral or synthetic lubricating
oils, and, particularly of the types hereinbefore described.
When high temperature stability is not a requirement of the
finished grease, mineral oils having a viscosity of at least
40 SSU at 150F., (4.2 cS at 66C) and particularly those
falling within the range from 60 SSU to 6000 SSU at 100F.
(10 to 1300 cS at 38C) may be employed. The lubricating
vehicles are combined with a grease-forming quantity of a
thickening agent. For this purpose, a wide variety of
materials may be employed. These thickening or gelling
agents include metal salts and soaps, non-soap thickeners,
such as surface-modified clays and silicas, aryl ureas,
I
~ ~ -5-
1/~38394
calcium complexes and similar materials. In general, grease
thickeners which do not melt and dissolve when used at the
required temperature within a particular environment are
preferred.
The following data and examples will serve to
illustrate the novel alkylamine salts of the present invent`~n
and
. .
~A
10383g4
their efficacy as lubricant improvers in anti-wear and friction
modifying characteristics in organic lubricant compositions.
It will be understood, however, that it i5 not intended the
invention be limited to the particular additives as described
and that various modifications thereof can be employed and will
be readily apparent to those skilled in the art.
Example l
In the comparative runs of this example, the additive
package component comprised, by weight: zinc dithiophosphate
1%, polymethyl methacrylate 3.3%~ aromatic oil swelling agent
2%, kerosene 0.1%, calcium sulfonate 8.6~, synthetic sulfurized
sperm oil 3%. In this example and in the remaining examples
the base oil comprised a solvent-refined paraffin base oil stock
dewaxed to a 0F. pour point.
~38394
Formulation
Material, Wt. % Run A Run B
Base Oil 81.75 81.50
Additive package 18.00 18.00
Methyl octadecyl acid phosphonate 0.25 0.25)
l-hydroxy ethyl-2-alkylimidazoline )*
of oleic acid 0.00 0.25)
*Reacted before blending
Test Results
SA~ Wear Test, 680607, 76 RPM
I50 lbs., 1/2 hr.
-
Weight loss, mg Fail in
10 Min. 12
Assessment Fail Pass
IHC Water Tolerance Test
14 days with 1% water
Separation of additive, Vol. ~ 0.2 None
The comparative data of the foregoing example illus-
trates the improved anti-wear and water tolerance properties
imparted by the alkylamine salts of the present invention.
Example 2
-
In the comparative runs of this example, the additive
package component comprised, by weight, the same additive package
employed in Example 1 except that the sulfurized sperm oil was
o~itted.
.
- 7 -
1038;3 94
Formulation
Material, Wt. % Run A Run B
Base Oil 84.50 84.50
Additive package 15.00 15.00
Methyl octadecyl acid phosphonate 0.50 0.25~
l-hydroxy ethyl-2-alkylimidazoline )*
~f oleic acid 0.00 0.25)
*Reacted before blending
Test Results
SAE Wear Testj 680607, 76 RPM,
Weight loss, mg 19 5
Assessment Pass Pass
IHC Water Tolerance Test
- 51% Water)
Additive separation after 14 days,
Vol. % O O
Additive separation after 21 days,
Vol. % o.6 0
Additive separation after 28 days,
Vol. % o.8 0
The comparative data of the foregoing example illus-
trates the improved anti-wear and water tolerance properties
imparted by the alkylamine salts of the present invention.
Example 3
In the comparative runs of this example, the additive
package component comprised, by weight: zinc dithiophosphate
~7~, polymethyl methacrylate 3%, aromatic oil swelling agent 2%,
. kerosene 0.1%, calcium sulfonate 7%. The John Deere Tractor
3 Chatter Index test is fully described in U.S. Patent 3,652,410.
Formulation ~ ~38394
Material, Wt. % Run ~ Run B
Base Oil 86.70 86.70
Additive package 12,80 12.80
Methyl octadecyl acid phosphonate 0.50 0.25
l-hydroxy ethyl-2-alkylimidazoline *
of oleic acid 0.00 0.25
*Reacted before blending
Test Results
John Deere Tractor Chatter Index 184 186
4-Ball Wear Scar, mm
(40 kg, 2 hrs., 200F., 600 rpm) 0.50 0.45
The comparative data of the foregoing example illus-
trates the improved anti-wear performance and equivalent
chatter control imparted by the alkylamine salts of the present
invention.
Example 4
In the comparative runs of this example, the additive
package component comprised, by weight: polymethyl methacrylate
2.4%, sulfurized isobutylene 1.8%, polybutenyl succinimide of
tetraethylpentamine 1%, kerosene 0.75%, alkyl ester of alkyl
dithioph~sphoric acid 0.2%, alkyl derivative of 2,5 dimercapto
1,3,4 thiadiazole 0.1%.
38394
Formulation
Material, Wt. % Run A Run B
Base Oil 93.25 93.25
Additive package 6~25 6.25
Methyl octadecyl acid phosphonate 0.50 0.25
l-hydroxy ethyl-2-alkyllmidazoline *
of oleic acid 0.00 0.25
*Reacted before blending
Test Results
Precipitate after 30 days storage Heavy None
at room temperature
The comparative data of the foregoing example illus-
trates the inefficacy of the methyl octadecyl acid phosphonate,
as a free acid, in forming a precipitate after 30 days.
Example 5
In the comparative runs of this example, the additive
package component comprised, by weight: polymethyl methacrylate
2.4%, sulfurized isobutylene 1.8%, polybutenyl succinimide of
tetraethylpentamine 1.0%, alkyl ester of alkyl dithiophosphoric
acid 0.2%, dibutylphosphonate 0.4%, kerosene 0.75%, alkyl
derivative of 2,5 dimercapto 1,3,4 thiadiazole 0.1%.
-- 10 --
~ 038394
Formulation
Material, Wt. % Run A Run B
Base Oil 93.35 92.85
Additive package 6.65 6.65
Methyl octadecyl acid phosphonate 0.00 0.25)
l-hydroxy ethyl-2-alkylimidazoline ~*
of oleic acid 0.00 0.25
~Reacted be~ore blending
Test ~esults
-
John Deere Oxidation Test
~00 hrs. at ~OOUF.)
% Viscosity change at 210F. 4.30 2.74
% Viscosity change at 100F. 12.44 7.41
Humidity Cabinet, 120F.
Hours to rust 24 48
The comparative data of the foregoing example illus-
trates the improved performance in areas of oxidative stability
and anti-rust properties imparted by the alkylamine salts of
the present invention.
Example 6
In the comparative runs of this example, the additive
package component comprised, by weight: polymethyl methacrylate
2.4~o~ polybutenyl succinimide of tetraethylpentamine 1.0%,
barium sulfonate 1.0%, alkyl ester of aryl dithiophosphoric
acid 2%, kerosene 0.1%.
Formulation 1~394
Material, Wt. % Run A Run B
Base Oil 93 50 93.oo
Additive package 6.50 6.50
Methyl octadecyl acid phosphonate 0;00 0.25)
l-hydroxy ethyl-2-alkylimidazoline )*
of oleic acid 0.00 0.25)
~Reacted before blending
Test Results
Humidity Cabinet, 120F.
Rating at 96 hours Fail Pass
SAE Wear Test
76 RPM, 150 lbs. wt. 106s, m~. Failed at 150 lbs 74
156 " , 400 " Failed at 180 lbs.877
The comparative data of the foregoing example illus-
trates the improvement in anti-wear and anti-rust performance
~ lmparted by the alkylamine salts of the present invention.
Example 7
In the comparative runs ofthisexample the additlve
package component comprised, by weight, 0.70% of a zinc dialkyl
dlthiophosphate, 3.30% of a methacrylate polymer viscosity
index improver, 2.00% of a hi~h boiling aromatic seal swell
agent, 0.10% of a silicone defoamant solution (in kerosene),
8.60% of a calcium overbased petroleum sulfonate.
~he compositions shown below were tested and the
results were as shown (the amine reactant and the acid phosphonate
pre-reacted):
Run No.
Formulation (Wt. %) 1 2 3 4
Base Stock 85.30 84.80 84.85 84.84
Additive packa~e 14.70 14.70 14.70 14.70
Methyl octadecyl acid 2 0 25 0 25
phosphonate -- O. 5
Oleyl imidazoline ~- 0.25 -- --
Oleylamine ~~ -- 0.20 --
Dimethylsoya amine ~ 0.21
1~38394
Test Results
Catalytlc Oxidation,
air/hr.
Increasein 210P~ --y ~ 6.8 5.8 4.1 6.7
IHC Water Tolerance ------------~~-
(1% Water) , ` ~~_ ~ - ~ ~~
Additive separation ~~~ ~~
after 21 days None None None None
Humldity Cabinet,120F
Rating at 96 Hrs. Pass Pass Pass Pass
SAE Wear Test
7~ RPM, 150 lbs. Pass Pass Pass Pass
! . LVFA Borg-Warner
SD 715 Paper on Steel
Coefficient of Static
Friction at 200F 0.136 0.120 0.125 0.130
~ .... . . . . .
While preferred embodiments of the novel organic
, .
lubricant compositions of the present invention have been des-
cribed for the purpose of illustration, it will be understood
I that various modifications and adaptations thereof, which will
i be obvious to those skilled in the art, may be made without
departing from the spirit of the invention.
