Additives for fuels and lubricants

Polyalkylene amine coupled carboxylates are effective multifunctional additives, providing cleanliness to fuels and lubricants as well as friction-reducing and corrosion-inhibiting properties.

FIELD OF THE INVENTION 
This invention is directed to polyalklene amines which have been reacted 
with carboxylate groups to form polymeric amine carboxylates, and the use 
of the resulting products as additives in fuels and lubricants. More 
particularly, it is directed to fuel and lubricating compositions 
containing such additives. 
BACKGROUND OF THE INVENTION 
Additives impart special qualities to fuels and lubricants, providing new 
properties or enhancing those already present. The use of polyalkylene 
amines in fuel compositions as detergents is well known. They are 
effective in maintaining the cleanliness of the mixture formation and 
intake system of gasoline engines (i.e., carburetor, injection nozzles, 
intake valves and mixture distributor), since they enable fuels to 
decompose cleanly at high temperatures leaving little or no residue. Fuel 
additives also reduce emissions from internal combustion engines. 
Polyalkylene amines have also been used as detergents in lubricants, in 
which they impart cleanliness and stability at high temperatures. 
Polyalkylene amines have generally been used as detergent additives. Other 
additives have been necessary to impart good friction reducing properties 
as well as antiwear and corrosion-inhibiting properties to the fuel or 
lubricant. 
The beneficial effects of the product of the instant invention are believed 
to be the result of an internal synergism between the polyalkylene amine 
groups, and carboxylate groups. The additives of this invention show good 
thermal decomposition and oxidative stability and compatibility with other 
commonly used fuel or lubricant additives when admixed with them. They are 
effective performance enhancers in either fuel or lubricant compositions. 
DESCRIPTION OF THE PRIOR ART 
The use of polyalkyleneamines as additives in lubricant compositions is 
well known in the prior art. U.S. Pat. No. 5,152,909 (DeRosa et al) 
discloses the use of polyisobutyleneamines in the preparation of 
antioxidant and corrosion resistance additives for railway crankcase 
lubricants. Although the polyisobutyleneamines of DeRosa et al are linked 
with anhydrides, a type of carboxylate, to form the additive, they differ 
from the instant invention in the chemistry of their synthesis. DeRosa et 
al reacts maleic anhydride with oligomeric polyisobutylene to form 
oligomeric anhydride. The anhydride then reacts with n-alkyl diamine. The 
intermediate then reacts with polyaromatic diisocyanate, then with 1,3,4 
thiadiazole. 
U.S. Pat. Nos. 5,004,478 (Vogel et al); 5,112,364 (Rath et al) and 
DE3942860 disclose the use of polyisobutylenes amines alone as gasoline 
and fuel additives. These compositions provide thermal decomposition and 
cleanliness features. The polyisobutyleneamine additives of these 
inventions are not coupled with other compounds as in the instant 
invention. 
Low molecular weight sulfur-containing heterocyclic additives such as those 
disclosed in U.S. Pat. Nos. 4,382,869 (Horodysky et al) and 4,301,019 
(Horodysky et al) provide friction reducing and antiwear properties for 
lubricant applications. These compositions, however, do not provide the 
thermal decomposition and cleanliness features, coupled with the excellent 
detergency properties of the new fuel additives disclosed in the instant 
invention. These properties are critical for severe service fuel and 
lubricant applications. 
SUMMARY OF THE INVENTION 
The instant invention is directed to novel adducts of polymeric amines. 
More particularly, it is directed to products of fatty acids which are 
reacted with polyalkylene amines to form polymeric amine carboxylates. It 
has now been found that the use of polymeric amine carboxylates as 
additives in fuels and lubricant compositions can provide both excellent 
friction reducing and fuel economy improving properties coupled with 
superior high temperature thermal decomposing and cleanliness properties 
for use in light distillate hydrocarbon and/or oxygenated fuels. 
Additional detergency, corrosion inhibiting, metal deactivating and/or 
antioxidant properties are also potentially present. 
The compositions of the instant invention are readily made in a one-step 
procedure that could, in one embodiment, be implemented during blending of 
the fuel additive component packages. For example, the components of this 
invention could be reacted together using an in-line mixer as a reactor, 
then promptly blended into the fuel. These additives could provide 
desirable performance features at a modest cost. Furthermore, they do not 
contain any environmentally or toxicologically undesirable materials or 
corrosive raw materials. Use in either fuels or lubricants could also 
reduce harmful emissions generated by internal combustion engines. 
DESCRIPTION OF THE PREFERRED EMBODIMENTS 
This invention is directed to additives suitable for use in fuels or 
lubricant oils prepared in a process comprising reacting in a suitable 
reaction zone a polyalkylene amine having an average molecular weight of 
about 500 to 2000 amu, and a carboxylate group such as an anhydride. The 
preferred polyalkyleneamines are those having a long chain hydrocarbon 
group of at least about 30 carbon atoms, preferably 30 to 120 carbon 
atoms. Amines of this type include polyisobutyleneamine. Such amines might 
also include alternate polymeric amines such as those below: 
##STR1## 
Polyalkyleneamines useful in this invention can be prepared by chlorination 
or hydroformulation of a reactive polyolefin such as polyisobutylene, and 
subsequent amination with ammonia, hydrocarbyl amine, hydrocarbyl diamine, 
hydrocarbyl polyamine, alkoxylated hydrocarbyl amines, or mixtures 
thereof. Ammonia, ethylenediamine, propylenetriamine, diethylenetriamine, 
triethylenetetramine, tetraethylenepentamine, piperazines, 
hexamethylenediamine, hydroxyalkylethylenediamines, hydroxyalkyl 
triethyleneteramines, and similar compounds can be converted to 
polyalkyleneamines by these procedures. Mixtures of the above and similar 
amines can also be used effectively. Alternatively, these amines can be 
prepared by chlorination or halogenation of appropriate polymeric olefins, 
and then converted into corresponding polyalkyleneamine derivatives using 
these or other known methods of manufacture. 
Polyisobutylene (PIB) is an oligomeric isobutylene segment containing 
random 1,2 and 1,4-butylene repeat units shown below: 
##STR2## 
where the sum of the repeat units, b and c respectively, vary from 10 to 
50 so that the oligomer has a corresponding molecular weight range between 
500 and 2000 amu, preferably 1000 amu. The polyalkylene amines can also 
optionally contain sulfur, oxygen or additional nitrogen and may have 
other functional groups. 
The generalized reaction is as follows; 
--NH2+Carboxylate Group=Detergent with Friction-Reducing Properties 
Carboxylate sources effective in the instant invention can include fatty 
acids, dimerized or trimerized acids, as well as functionalized acids such 
as sarcosines derived from acylated glycines. The carboxylate sources can 
contain from 10 to 50 or more carbon atoms, and can also optionally 
contain sulfur, nitrogen, or additional oxygen. Desirable carboxylates can 
include carboxylic acids, as well as carboxylate generating species such 
as anhydrides. 
A dimer acid is a high molecular weight dibasic acid, which is liquid 
(viscous), stable, resistant to high temperatures, and which polymerizes 
with alcohols and polyols to yield a variety of products, such as 
plasticizers; lube oils, hydraulic fluids. It is produced by dimerization 
of unsaturated fatty acids at mid-molecule and usually contains 36 
carbons. Trimer acid, which contains three carboxyl groups and 54 carbons, 
is similar. 
The pressures employed in the instant invention range from subatmospheric 
to 500 psig. More preferred is the range from 50 to 500 psig. The 
temperature may range broadly from 0.degree. C. (32.degree. F.) to 
150.degree. C. (300.degree. F.), more specifically from 60.degree. C. 
(140.degree. F.) to 80.degree. C. (176.degree. F.). Solvents useful in the 
instant invention include aromatic and aliphatic hydrocarbons which 
contain from 5 to 15 carbon atoms. The solvent can optionally contain 
additional oxygen, sulfur or nitrogen. 
Some of the most effective carboxylate groups in the instant invention 
include fatty acids such as oleic acid, dimerized fatty acids (such as 
dimerized linoleic acids), and acyl sarcosines (such as oleoyl sarcosine). 
CH.sub.3 --(CH.sub.2).sub.7 CH.dbd.CH(CH.sub.2).sub.7 COOH Oleic acid 
CH.sub.3 --(CH.sub.2).sub.4 CH.dbd.CHCH.sub.2 CH.dbd.CH(CH.sub.2).sub.7 
COOH Linoleic acid 
Two products of reaction, employing PIB-amine oleates and PIB-amine 
sarcosinates, are illustrated in a general form below, where R represents 
alkyl chains of from 10-50 carbon atoms, preferably 18-36 carbon atoms: 
##STR3## 
An excess of one reagent or another can be used in the instant invention. 
Molar quantities, or less than molar quantities of either polyalkylene 
amine or carboxylate generating species can be used. Preferred quantities 
of the acid range from less than molar to equimolar. 
The fuels combined with the additive of this invention are liquid 
hydrocarbon combustion fuels, including the distillate fuels, i.e., 
gasoline and fuel oils. Accordingly, the fuel oils that may be improved in 
accordance with the present invention are hydrocarbon fractions having an 
initial boiling point of at least about 100.degree. F. and an end-boiling 
point no higher than about 750.degree. F. and boiling continuously 
throughout their distillation range. These fuel oils are generally known 
as distillate fuel oils. It is to be understood, however, that this term 
is not restricted to straight run distillate fractions. The distillate 
fuel oils can be straight run distillate fuel oils, catalytically or 
thermally cracked (including hydrocracked) distillate, gasoline, fuel 
oils, alcohols, oxygenated hydrocarbons, or mixtures of straight run 
distillate fuel oils, naphthas and the like, with cracked distillate 
stocks. Moreover, such fuel oils can be treated in accordance with well 
known commercial methods, including acid or caustic treatment, 
hydrogenation, solvent refining, clay treatment and the like. The 
distillate fuel oils are characterized by their relatively low 
viscosities, pour points, and similar properties. The principal property 
which characterizes the contemplated hydrocarbons, however, is the 
distillation range. As mentioned previously, this range lies between about 
100.degree. F. and about 750.degree. F. The distillation range of each 
individual fuel oil will cover a narrower boiling range, but falling, 
nevertheless, within the above specified limits. Likewise, each fuel oil 
with boil substantially continuously throughout its distillation range. 
Contemplated among the fuel oils are numbers 1, 2, 3 fuel oil (useful in 
heating and in diesel engines), and the jet combustion fuels. The domestic 
fuel oils generally conform to the specifications set forth in ASTM 
Specifications D396-48T. Specifications for diesel fuels are defined in 
ASTM Specification D975-48T. Typically jet fuels are defined in Military 
Specifications. The specifications may at times be slightly varied. 
The gasolines that are improved by the additive compositions of this 
invention are mixtures of hydrocarbons having an initial boiling point 
falling between about 75.degree. F. and about 135.degree. F. and an 
end-boiling point falling between about 250.degree. F. and about 
450.degree. F. As is well known in the art, motor gasoline can be straight 
run stock, catalytic or thermal reformate, cracked stock, alkylated 
natural gasoline and aromatic hydrocarbons. All of these are contemplated. 
If the additive compositions of this invention are to be incorporated into 
a lubricating oil they are added in a concentration of between 0.1 wt % 
and 2.0 wt %. If the composition is to be incorporated into a fuel such as 
distillate or gasoline, the concentration is between 1 and 500 pounds per 
thousand barrels. More preferably concentrations in a range between 5 and 
100 pounds per thousand barrels of fuel can be used. 
Of particular significance in the instant invention, in the case of 
lubricants, is the ability to impart cleanliness and stability features at 
high temperatures. The additives of this invention also improve the 
resistance to oxidation and corrosion of oleaginous materials. Such 
materials include lubricating media which may comprise liquid oils, in the 
form of either a mineral oil, or a synthetic oil, or mixtures thereof, or 
in the form of a grease in which any of the aforementioned oils are 
employed as a vehicle. Other additives, such as corrosion inhibitors, 
ignition enhancers, antiknock additives, auxiliary detergents, etc. can be 
readily used in fuels in conjunction with the compositions of this 
invention. 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 about 45 
SUS at 100.degree. F. to about 600 SUS at 100.degree. F., and preferably, 
from about 40 SUS to about 250 SUS at 210.degree. F. These oils may have 
viscosity indexes ranging to about 100 or higher. Viscosity indexes from 
about 70 to about 95 are preferred. The average molecular weights of these 
oils may range from about 250 to 800. Additional agents, such as auxiliary 
detergents, corrosion inhibitors, antioxidants, antiwear agents, 
friction-reducing agents, etc. can be useful. Such agents can include 
phenates, sulfonates, succinimides, organic borates, phenols, succinic 
esters, amides, or dithiophosphates. Other additives may include polymeric 
viscosity index improvers. 
Having described the invention broadly, the following are offered as 
specific illustrations. They are illustrative only and are not intended to 
limit the invention.

EXAMPLE 1 
Reaction Product of Polyisobutyleneamine and Oleic Acid 
About 147 g of an approximately 50% solution of polyisobutyleneamine in a 
hydrocarbon solvent having a molecular weight of about 1,000 g was 
combined with 22.5 g oleic acid in a reactor equipped with a heater and 
agitator. 
The remaining 50% of the solution is comprised of a hydrocarbon solvent. 
After a slight exotherm to approximately 38.degree. C. (100.4.degree. F.), 
the reactants were heated to 75.degree. C. (167.degree. F.) with agitation 
for one hour. The final product yield at room temperature was 169 g of PIB 
amine oleate, a clear yellow liquid. 
EXAMPLE 2 
Reaction Product of Polyisobutyleneamine and Oleic Acid 
The generalized procedure of Example 1 was followed, but 295 g of the above 
polyisobutyleneamine solution and 45 g of oleic acid were used. The final 
product yield was 339 g of PIB amine oleate, a clear yellow liquid, at 
room temperature. 
EXAMPLE 3 
Dehydrated Reaction Product of Polyisobutyleneamine and Oleic Acid 
About 147 g of an approximately 50% solution of polyisobutyleneamine having 
a molecular weight of 1,000 g (the solution of Example 1), 22.5 g of oleic 
acid, and 50 ml toluene auxiliary solvent, were placed in a reactor 
equipped with agitator, heater, Dean-Stark tube with condenser, and 
provisions for blanketing the vapor space with inert (nitrogen) gas. 
Toluene was used to facilitate azeotropic water removal. The ingredients 
were heated to 75.degree. C. (167.degree. F.) with agitation for one hour. 
The temperature was then slowly raised to 166.degree. C. (330.8.degree. 
F.) for approximately 5 hours until water evolution during azeotropic 
distillation ceased. A total of 1 ml of water was collected. The product 
was distilled under reduced pressure to remove volatiles. Approximately 
103 g of PIB amine oleate, a clear yellow viscous fluid, was isolated as 
product. 
EXAMPLE 4 
Reaction Product of polyisobutyleneamine, and Dimer Acid 
Approximately 184 g of the polyisobutylene solution described in Example 1 
was combined with 56 g of dimer acid (dimerized linoleic acid commercially 
obtained as Hystrene 3675 dimer acid) in a reactor equipped with a heater 
and agitator. After a slight exotherm to about 37.degree. C. (98.6.degree. 
F.), the reactants were heated to 75.degree. C. (167.degree. F.) with 
agitation for one hour. The product was a yellow/orange liquid 
(monolinoleate) when cooled to room temperature. 
EXAMPLE 5 
Reaction Product of Polyisobutyleneamine, and Dimer Acid 
The generalized procedure of Example 4 was followed, but 184 g of the above 
polyisobutyleneamine solution and 28 g of the above dimer acids were used. 
After a slight exotherm to 34.degree. C. (93.2.degree. F.), the reactants 
were heated to 75.degree. C. (167.degree. F.) with agitation for one hour. 
The product, the di-linoleate, was a clear yellow liquid at room 
temperature. 
EXAMPLE 6 
Reaction Product of Polyisobutyleneamine, and Oleoyl Sarcosine 
The generalized procedure of Example 1 was followed, but 184 g of the 
polyisobutyleneamine solution and 34.9 g of oleoyl sarcosine (commercially 
obtained as Hamposyl O from the Hampshire Chemical Co.) were used. After a 
slight exotherm to approximately 33.degree. C. (91.4.degree. F.) the 
reactants were heated to 75.degree. C. (167.degree. F.) with agitation for 
one hour. The product, oleoyl sarcosinate, was a clear yellow liquid after 
cooling to room temperature. 
EXAMPLE 7 
Reaction Product of Polyisobutyleneamine, and Lauroyl sarcosine 
The generalized procedure of Example 6 was followed, but 92 g of the 
polyisobutyleneamine solution and 13.5 g of lauroyl sarcosine 
(commercially obtained as Hamposy L from Hampshire Chemical Co.) were 
used. After a slight exotherm to approximately 34.degree. C. (93.2.degree. 
F.), the reactants were heated to 75.degree. C. (167.degree. F.) with 
agitation for one hour. The product, lauroyl sarcosinate, was a clear 
yellow liquid after cooling to room temperature. 
EXAMPLE 8 
Reaction product of Polyisobutyleneamine and Cocoyl Sarcosine 
The generalized procedure of Example 6 was followed, but 92 g of the 
polyisobutyleneamine solution and 14 g of cocoyl sarcosine (commercially 
obtained as Hamposyl C from Hampshire Chemical Co.) were used. After a 
slight exotherm to approximately 37.degree. C. (98.6.degree. F.), the 
reactants were heated to 75.degree. C. (167.degree. F.) with agitation for 
one hour. The product, cocyl sarcosinate, was a clear yellow liquid after 
cooling to room temperature. 
Thermal Decomposition Properties 
The products of the Examples were evaluated with respect to cleanliness 
during thermal decomposition using thermogravimetric analysis as shown in 
Table 1 below. Thermogravimetric analysis was performed by heating the 
sample at 20.degree. C./min in air flowing at 100 ml/min using a 
thermogravimetric analyzer. The percent residue remaining at 425.degree. 
C. was recorded; little or no residue is most desirable. As can be seen 
from the thermogravimetric analysis results, the products of this 
invention show exceptional cleanliness and high temperature decomposition 
features. Examples 7 & 8 left the least amount of residue. 
TABLE 1 
______________________________________ 
High Temperature Performance/Cleanliness 
Thermogravimetric Analysis 
% Residue Temp. for 0% 
Examples @ 425.degree. C. (797.degree. F.) 
Residue, .degree.C. 
.degree.F. 
______________________________________ 
1 0.4 475 887 
2 0.0 406 762.8 
3 1.3 524 
6 1.3 532 989.6 
7 0.0 425 797.0 
8 0.0 415 779.0 
______________________________________ 
Frictional Properties 
The frictional properties of the compositions of this invention were then 
evaluated using the Low Velocity Friction Apparatus Test. Two weight 
percent of the additive was dissolved in a standard mineral oil reference 
fluid blended with a dispersant/detergent/inhibitor (DDI) performance 
package. The percent reduction in coefficients of friction relative to the 
reference oil was measured at 32-58 psi over a range of sliding speeds 
(5-30 ft/min) at both room temperature and at 250.degree. F. The percent 
change in the coefficients of friction of the test oil with the examples 
when compared to the test oil without the examples is reported in Table 2 
using an average of pressures at both 32 and 48 psi. 
TABLE 2 
______________________________________ 
Reduction of Coefficients of Friction 
Example Reduction in Friction, % 
______________________________________ 
Reference oil 0 
Reference plus 2 wt % Example 1 
42 
Reference plus 2 wt % Example 2 
41 
Reference plus 2 wt % Example 3 
3 
______________________________________ 
The friction test results clearly show the friction reducing potential of 
these additives. It is interesting to note that the dehydrated product of 
Example 3 shows that dehydration suppresses the friction reducing 
potential of these compositions. 
Catalytic Oxidation Test 
The products of these Examples were then evaluated with respect to 
oxidative stability and corrosion reducing properties. In the Catalytic 
Oxidation Test the reference lubricant is subjected to a stream of air 
which is bubbled through at a rate of 5 liters per hour and 325.degree. F. 
for forty hours. Present are samples of metals commonly used in engine 
construction such as iron, copper, aluminum and lead. U.S. Pat. No. 
3,682,980, herein incorporated by reference in its entirety, may be 
consulted for more complete details of the test. Minimization of viscosity 
increase or neutralization number shows control of oxidation. The data are 
reported as increase in viscosity (%), increase in Total Acid number 
(TAN), and amount of lead loss, in mg., as shown in Table 3. 
TABLE 3 
______________________________________ 
Oxidative Stability/Corrosion Inhibition 
Viscosity Acid No. Lead 
Example Increase % 
Increase Loss, mg 
______________________________________ 
Fully formulated synthetic 
-2% 0.48 0.2 
engine oil with DDI package 
Reference oil plus 2 wt % of 
0% 0.71 0.8 
product of Example 1 
______________________________________ 
The results clearly show that the products of this invention do not 
adversely affect the oxidative stability or corrosivity of petroleum 
products formulated therefrom. Slight increases in acid number and lead 
loss were noted, confirming good control of these two key properties which 
measure oxidative performance. 
Copper Corrosivity 
Example 1 was evaluated with respect to copper corrosivity properties. Two 
percent of Example 1 was blended into a 200 SUS solvent paraffinic neutral 
lubricating oil and evaluated using the Copper Strip Corrosivity Test, 
ASTM D-130 at 250.degree. F. (121.11.degree. C.) for three hours. The 
result were rated as 1A, indicating no corrosive tendencies. In fact, 1A 
is the best possible rating using this test for copper corrosivity.