Note: Descriptions are shown in the official language in which they were submitted.
27695
1~33V12
AMIDES FROM ARALRYL ACIDS AND
POLYAMINES AS LUBRICANT ADDITIVES
Background of the Invention
This invention relates to additives for hydrocarbons suitable
for use in an internal combustion engine. In one of its aspects, this
invention relates to detergent additives for lubricants and hydrocarbon
fuels.
It is common practice to add detergent compounds, detergent
compositions, or detergent packages, i.e., a mixture of detergent
compositions along with other additives, to lubricant and fuel
compositions to prevent the deposition of solid materials on engine
surfaces which come into contact with the lubricant or fuel compositions.
The deposits formed in the engine interfere with the proper circulation
of the lubricant and fuel compositions and also act as abrasives which
can aggravate the wearing of engine parts.
It has also been found that some detergent additives that have
been employed in lubricant and fuel compositions actually contribute to
the formation of deposits in modern engines. It is, therefore, always of
interest when compounds or compositions that provide improved detergent
additive properties are discovered.
It is, therefore, an object of this invention to provide a
detergent additive for internal combustion engine fuels and lubricants.
It is another object of this invention to provide a method for retarding
the depositing of solid materials on the surfaces of internal combustion
engines. It is still another object of this invention to provide
detergent fuel compositions and detergent lubricating compositions for
internal combustion engines.
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Other aspects, objects and the various advantages of this
invention will become apparent upon reading the specification and the
appended claims.
Statement_of the Invention
In accordance with this invention, detergent additives for
lubricants and fuels for use in internal combustion engines is provided.
The detergent additive is those amides made by reaction between aralkyl
acids and polyamines. The detergent lubricant and fuel additives are
particularly effective to keep two-cycle, outboard engines clean.
In one of its embodiments, this invention provides a fuel or
lubricant composition for use in internal combustion engines. The
composition is a mixture of a fuel or lubricant with a detergent additive
amide, produced as described above.
In still another embodiment of the invention a method is
provided for maintaining the cleanliness of an internal combustion
engine by the addition to the hydrocarbon fuel or lubricant for the
engine of a detergent additive amide produced as described above.
Aralkyl acids that are suitable for use to synthesize the
additive are those acids that can be prepared by alkylation of an
aromatic hydrocarbon such as benzene, toluene, xylenes, or the like with
an unsaturated fatty acid such as the mono-unsaturated acids lauroleic,
myristoleic, palmitoleic, oleic, gadoleic, and the like, or with poly-
unsaturated fatty acids such as linoleic, linolenic, or moroctic acids--
Cl~ acids having two, three, and four double bonds, respectively. The
aralkyl radical R of the acids (RCOON) can contain from about 11-41
carbon atoms; preferably it will contain 17-29 carbon atoms. Examples of
suitable aralkyl acids are diphenyllauric acid, triphenylpalmitic acid,
phenyl stearic acid, and the like in which at least one aromatic radical
is combined in the original fatty acid.
Polyamines that are suitable for use can be represented by the
formula NH2(CH2CH2NH) H in which x is an integer between two and six.
Examples are diethylenetriamine, triethylenetetramine, and
tetraethylenepentamine. ~specially preferred is the latter amine in
which x is four.
The ratio in which aralkyl acid and polyamine are combined for
reaction is about 0.2-1.0 moles of acid per equivalent of nitrogen.
Preferably the ratio is between about 0.4-0.8 moles of acid per
equivalent of nitrogen.
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Production of amides by reaction between aralkyl acids and
polyamines is accompanied by the liberation of water, and is
facilitated by the use of temperatures above the normal boiling point
of water. Reaction can be effected without using a solvent by
operating under conditions in which water vapor is removed from the
reactants with the aid of a stream of gas, preferably inert, such as
nitrogen or argon. Alternatively the reaction can be effected in a
solvent such as a hydrocarbon that permits operation under reflux at a
temperature of about 100-200C. Since one mole of water is produced
per mole of amide, measurement of evolved water provides a convenient
method to follow the extent of the reaction.
In addition to being effective to maintain the cleanliness
of an outboard engine during extended operation, the additive of this
invention is useful to prevent or reduce the formation of harmful
carburetor and fuel intake system deposits when admixed with the fuel
of any internal combustion engines. For this application the additive
is used at a concentration of about 1-250 pounds per thousand barrels
of fuel.
The additive is also useful with lubricant stocks,
particularly solvent refined, paraffinic stock having a viscosity
index of 100 or above and a viscosity at 210F of about 39 to about
100 Saybolt Universal seconds (SUS), preferably about 45 to about 75
SUS. Other additives commonly used to formulate lubricants, such as
viscosity index improvers, antioxidants, and the like can be used in
formulation with the additive of this invention without destroying the
effectiveness of the additives.
The following example illustrates the preparation of an
amide that is subsequently shown to possess good detergent properties
when incorporated into the lubricant for a two-cycle outboard engine.
Example
Amide was prepared by combining 2238 g (6.0 moles)
of phenylstearic acid ~as commercially available from Armak Co.)
and 378 g (2.0 moles) of tetraethylenepentamine in a flask fitted
with a stirrer, a water-cooled reflux condenser, a Barrett water
trap, and a heating mantle. After addition of 835 ml of xylene
the mixture was heated to boiling and maintained at reflux for
3.2 hours during which interva] 125 ml (6.9 moles) of water was
collected. Water in excess of the expected 6.0 moles was
presumably present as an impurity in the reactants. Solvent was
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removed from the product by distillation at 132C kettle temperature at 7
torr pressure.
The solvent-free additive was incorporated into a lubricating
oil blend at a concentration of 10.1 volume percent. The resulting
mixture was combined with gasoline in the volume ratio 1:50,
respectively, and tested for 100 hours in a 25 horsepower Johnson two-
cycle outboard engine at wide open throttle (about 4800-4900 rpm~ except
for five minutes of idling at hourly intervals. The additive was
evaluated by the Piston Varnish Test, a rating system developed by the
Coordinating Research Council (CRC) that indicates the relative amount
of varnish deposit on a piston. In this system a rating of 10 designates
a clean piston and zero designates a very dirty one. This system is used
by the Boating Industry Association to certify two-cycle lubricants for
service TC-W. A satisfactory additive should produce a Piston Varnish
rating of at least 9Ø The additive made and evaluated as described in
this example received a 9.7 rating.
