Succinimides useful as detergents in fuels are prepared by reacting (a) at least one substituted succinic acid or acid derivative thereof containing an average of from 16 to about 50 carbon atoms in the molecule and having an acyclic aliphatic substituent group containing an average of at least 12 but less than 30 carbon atoms, with (b) at least one alkanol polyamine containing an average of at least 4 carbon atoms and containing at least one primary amino group.

TECHNICAL FIELD 
This invention relates to detergents for internal combustion engines More 
particularly it relates to novel ashless dispersant-detergents capable of 
reducing and/or preventing the deposit of solid materials in internal 
combustion engines and in particular in the fuel intake systems and/or 
related engine parts. 
BACKGROUND 
The prior art discloses many ashless dispersants useful as additives in 
fuels and lubricant compositions. A large number of such ashless 
dispersants are derivatives of high molecular weight carboxylic acid 
acylating agents. Typically, the acylating agents are prepared by reacting 
an olefin (e.g., a polyalkene such as polybutene) or a derivative thereof, 
containing for example at least 30 to 50 aliphatic carbon atoms, with an 
unsaturated carboxylic acid or derivative thereof such as acrylic acid, 
methacrylic acid, maleic acid, fumaric acid and maleic anhydride. 
Dispersants are prepared from the high molecular weight carboxylic acid 
acylating agents by reaction with, for example, amines characterized by 
the presence within their structure of at least one N-H group, alcohols, 
reactive metal or reactive metal compounds, and combinations of the above. 
U.S. Pat. No. 4,234,435 summarizes some of the prior art relative to the 
preparation of such carboxylic acid derivatives. 
It also has been suggested that the carboxylic acid derivative compositions 
such as those described above can be post-treated with various reagents to 
modify and improve the properties of the compositions. Acylated nitrogen 
compositions prepared by reacting the acylating reagents described above 
with an amine can be post-treated, for example, by contacting the acylated 
nitrogen compositions thus formed with one or more post-treated reagents 
selected from the group consisting of boron oxide, boron oxide hydrate, 
boron halides, boron acids, esters of boron acid, carbon disulfide, 
sulfur, sulfur chlorides, alkenyl cyanides, carboxylic acid acylating 
agents, aldehydes, ketones, phosphoric acid, epoxides, etc. Lists of the 
prior art relating to post-treatment of carboxylic ester and amine 
dispersants with reagents such as those described above are contained in a 
variety of patents such as U.S. Pat. Nos. 4,203,855 (Col. 19, lines 16-34) 
and 4,234,435 (Col. 42, lines 33-46). 
U.S. Pat. No. 3,216,936 describes lubricant additives which are 
compositions derived from the acylating of alkylene polyamines. More 
specifically, the compositions are obtained by reaction of an alkylene 
amine with an acidic mixture consisting of a hydrocarbon-substituted 
succinic acid having at least about 50 aliphatic carbon atoms in the 
hydrocarbon group and an aliphatic monocarboxylic acid, and thereafter 
removing the water formed by the reaction. The ratio of equivalents of 
said succinic acid to the mono-carboxylic acid in the acidic mixture is 
from about 1:0.1 to about 1:1. The aliphatic mono-carboxylic acids 
contemplated for use include saturated and unsaturated acids such as 
acetic acid, dodecanoic acid, oleic acid, naphthenic acid, formic acid, 
etc. Acids having 12 or more aliphatic carbon atoms, particularly stearic 
acid and oleic acid, are especially useful. The products described in the 
'936 patent also are useful in oil-fuel mixtures for two-cycle internal 
combustion engines 
British Pat. No. 1,162,436 describes ashless dispersants useful in 
lubricating compositions and fuels. The compositions are prepared by 
reacting certain specified alkenyl substituted succinimides or succinic 
amides with a hydrocarbon-substituted succinic acid or anhydride. The 
arithmetic mean of the chain lengths of the two hydrocarbon substituents 
is greater than 50 carbon atoms. Formamides of monoalkenyl succinimides 
are described in U.S. Pat. No. 3,185,704. The formamides are reported to 
be useful as additives in lubricating oils and fuels. 
U.S. Pat. Nos. 3,639,242 and 3,708,522 describe compositions prepared by 
post-treating mono- and polycarboxylic acid esters with mono- or 
polycarboxylic acid acylating agents. The compositions thus obtained are 
reported to be useful as dispersants in lubricants and fuels. 
U.S. Pat No. 4,780,111 describes fuel compositions containing a 
hydrocarbon-soluble dispersant prepared generally by the post-treatment of 
a nitrogen-containing composition with mono- and polycarboxylic acids 
which may be aliphatic or aromatic carboxylic acids, preferably the 
latter. The nitrogen-containing compositions which are post-treated in 
accordance with U.S. Pat. No. 4,780,111 are obtained by reacting an 
acylating agent with alkylene polyamines or alkanol amines. The patent 
reports that when such fuel compositions are utilized in internal 
combustion engines, and in particular, fuel-injected internal combustion 
engines, the amount of solid deposits on the various parts of the internal 
combustion engines are reduced. 
Use of such post-treatment procedures adds to the complexity of the 
production process and to the cost of the product so formed. 
THE INVENTION 
This invention provides novel compositions of matter, more particularly 
novel additives useful as fuel detergents. Such compounds require no 
post-treatment procedures such as described for example in U.S. Pat. No. 
4,780,111. Moreover, the fuel compositions containing such additives have 
been found highly effective in reducing or preventing carburetor or 
injector deposit formation or build up in internal combustion engines. 
In accordance with one of its embodiments this invention provides a 
hydrocarbon-soluble succinimide prepared by reacting 
a) at least one substituted succinic acid or acid derivative thereof 
containing an average of from 16 to about 50 carbon atoms in the molecule 
and having an acyclic aliphatic substituent group containing an average of 
at least 12 (preferably at least 16) but less than 30 carbon atoms, with 
b) at least one alkanol polyamine containing an average of at least 4 
carbon atoms and containing at least one primary amino group. 
In another embodiment of this invention, the succinimide is formed from an 
alkanol polyamine with contains only one primary amino group in the 
molecule In still another embodiment of this invention, the alkanol 
polyamine used in forming the succinimide contains an average of more than 
one primary amino group in the molecule. In such case, the resultant 
succinimide may contain an average of one or less than one or more than 
one succinimide group per molecule. In yet another embodiment of this 
invention, the alkanol polyamine used in forming the succinimide contains 
an average of at least two primary amino groups in the molecule. 
This invention involves, inter alia, the discovery that by acylating an 
alkanol polyamine with a relatively short-chain acylating agent, a highly 
effective detergent for use in fuels can be formed without need for 
post-treatment such as is referred to and described for example in U.S. 
Pat. No. 4,780,111. Hence production and fuel treating costs can be kept 
to a minimum. Moreover, because the resultant succinimide product has a 
relatively low molecular weight, its content of polar constituency can be 
relatively high on a weight basis. Thus a given quantity of a detergent of 
this invention can provide the same effectiveness in inhibiting deposit 
formation on critical engine parts such as carburetor nozzles and the like 
as a substantially larger quantity of a polyamine acylated with a long 
chain acylating agent of the type described heretofore. And the detergents 
of this invention have good fuel solubility, and exhibit little if any 
tendency to leave gums or residues in areas where the fuel is aspirated, 
as in the carburetor or in other similar parts of the fuel intake systems. 
This invention involves the further discovery that certain structural 
configurations in the short chain succinic acid or acid derivative thereof 
can provide acylated alkanol polyamine detergents of exceptional 
effectiveness in keeping certain fuel intake system parts essentially free 
of deposits. 
Pursuant to one preferred embodiment of this invention the acylating agent 
used in making the above detergent is at least one substituted succinic 
acid or acid derivative thereof (anhydride, acyl halide or lower alkyl 
ester) containing an average of from 16 to about 50 carbon atoms in the 
molecule and having a substantially straight chain acyclic aliphatic 
substituent group (most preferably alkyl or alkenyl) containing an average 
of at least about 12 but less than 30, and preferably an average of at 
least 14 but no more than 28 carbon atoms. 
In another preferred embodiment the acylating agent used in making the 
above detergent is at least one substituted succinic acid or acid 
derivative thereof containing an average of from 16 to about 50 carbon 
atoms in the molecule and having an acyclic aliphatic substituent group 
bifurcated on its beta carbon atom into two branches, one of which 
contains at least 4 carbon atoms and the other of which contains at least 
6 carbon atoms, such substituent group containing an average of at least 
12 but less than 30 carbon atoms. 
Preferably, the alkanol polyamine used in forming the succimides with the 
preferred acylating agents referred to in the immediately preceding two 
paragraphs is one or a mixture of alkanol polyamines represented by the 
general formula 
##STR1## 
wherein Z is an alkylene group of from 2 to about 4 carbon atoms; each R 
is independently a hydrogen atom or an organic group which contains 1 to 
about 8 carbon atoms and is a hydrocarbyl, hydroxy-substituted 
hydrocarbyl, or primary amino-substituted hydrocarbyl group; and n is 1 to 
about 10; with the provisos that at least one R group is a 
hydroxy-substituted hydrocarbyl group, and that the compound contains at 
least one primary amino group. Use of 2-(2-aminoethylamino)ethanol is 
especially preferred. 
In accordance with still another preferred embodiment, the detergent is a 
hydrocarbon-soluble substituted succinimide represented by the general 
formula 
##STR2## 
where R is alkylene of 2 to 4 carbon atoms, R' is a substantially straight 
chain alkyl or alkenyl group averaging at least 12 but less than 30 and 
preferably at least 14 but no more than 28 carbon atoms, R" is a hydrogen 
atom or alkyl of 1 to 5 carbon atoms, and n is an integer in the range of 
1 to 10. 
In yet another preferred embodiment the detergent of this invention is a 
substituted succinimide represented by the general formula 
##STR3## 
where R is alkylene of 2 to 4 carbon atoms, R' is an alkyl or alkenyl 
group bifurcated on its beta carbon atom into two branches one of which 
contains at least 4 carbon atoms and the other of which contains at least 
6 carbon atoms, said group containing an average of at least 12 but less 
than 30 carbon atoms, R" is a hydrogen atom or alkyl of 1 to 5 carbon 
atoms, and n is an integer in the range of 1 to 10. 
These and other embodiments, features and advantages of this invention will 
become still further apparent from the ensuing description and appended 
claims. 
The compounds of this invention are especially useful as detergent 
additives for normally liquid hydrocarbon fuels in the gasoline boiling 
range, including hydrocarbon base fuels. The term "petroleum distillate 
fuel" also is used to describe the fuels which can be utilized in the fuel 
compositions of the present invention and which have the above 
characteristic boiling points. The term, however, is not intended to be 
restricted to straight-run distillate fractions. The distillate fuel can 
be straight-run distillate fuel, catalytically or thermally cracked 
(including hydrocracked) distillate fuel, or a mixture of straight-run 
distillate fuel, naphthas and the like with cracked distillate stocks. The 
hydrocarbon fuels also can contain non-hydrocarbonaceous materials such as 
alcohols, ethers, organo-nitro compounds, etc. Such materials can be mixed 
with the hydrocarbon fuel in varying amounts of up to about 10-20% or 
more. For example, alcohols such as methanol, ethanol, propanol and 
butanol, and mixtures of such alcohols are included in commercial fuels in 
amounts of up to about 10%. Other examples of materials which can be mixed 
with the fuels include diethyl ether, methyl ethyl ether, methyl tertiary 
butyl ether, and nitromethane. Also included within the scope of the 
invention are liquid fuels derived from vegetable or mineral sources such 
as corn, alfalfa, shale and coal. Also, the base fuels used in the 
formation of the fuel compositions of the present invention can be treated 
in accordance with well-known commercial methods, such as acid or caustic 
treatment, hydrogenation, solvent refining, clay treatment, etc. 
Gasolines are supplied in a number of different grades depending on the 
type of service for which they are intended. The gasolines utilized in the 
present invention include those designed as motor and aviation gasolines. 
Motor gasolines include those defined by ASTM specification D-430-73 and 
are comprised of a mixture of olefins, paraffins, isoparaffins, naphthenes 
and occasionally diolefins. Motor gasolines normally have a boiling range 
within the limits of about 70.degree. F. to 450.degree. F. while aviation 
gasolines have narrower boiling ranges, usually within the limits of about 
100.degree. F.-330.degree. F. 
Fuel compositions containing a minor, property improving amount of at least 
one hydrocarbon-soluble detergent of the type described herein have the 
desirable ability of preventing or minimizing undesirable engine deposits, 
especially in the carburetor and fuel injector nozzles. 
As noted above, the detergents for use in such hydrocarbon fuels are made 
from one or more aliphatic succinic acid acylating agents. As is well 
known, in reaction with co-reactive amines, such acylating agents may be 
used in the free acid form, in the form of a derivative thereof such as 
the anhydride, ester, acyl halide, or as a combination of any two or more 
of the foregoing. 
Preferred acylating agents are alkyl and/or alkenyl succinic anhydrides in 
which the alkyl or alkenyl group is substantially straight chain in 
configuration and contains 12 to 26 carbon atoms, and even more preferably 
an average of about 18 to about 24 carbon atoms. An especially preferred 
acylating agent of this type is octadecenylsuccinic acid or anhydride. 
Still another preferred acylating agent is an alkyl- or alkenylsuccinic 
acid or anhydride in which the alkyl or alkenyl group is bifurcated on the 
beta-carbon atom and is composed of two substantially linear chains. 
Preferred alkyl groups of this type may be represented by the formula 
##STR4## 
where n is an integer in the range of 2 to 10. A preferred group of such 
bifurcated alkenyl groups may be represented by the formula 
##STR5## 
where n is an integer in the range of 2 to 10. It will be understood and 
appreciated that the double bond in such alkenyl group may be isomerized 
to different positions from that depicted (which is the preferred 
position) by treating the alkenylsuccinic acid or anhydride with an 
isomerization catalyst such as silica gel, a trialkylborane, or the like. 
Such alkyl- and alkenyl-substituted succinic acids and anhydrides can be 
formed from dimerized 1-olefins such as by dimerizing 1-hexene, 1-heptene, 
1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 
4-methyl-1-pentene, 6-methyl-1-heptene, 5-ethyl-1-decene, or 
3,5,5-trimethyl-1-undecene with an aluminum alkyl dimerization catalyst 
according to known procedures. See for example Ziegler et al, Ann. 629, 
121-166 (1960) all disclosure of which is incorporated herein by 
reference. The resultant dimerized olefin (sometimes referred to as a 
vinylidene olefin) is then used to alkylate maleic anhydride or an ester 
of maleic acid, etc., to form the alkenyl-substituted succinic acid 
compound by the "ene" reaction. See in this connection Hoffman, Angew. 
Chem., Int. Ed. (English), 8, 556-577 (1969); Snider, J. Org. Chem., 39, 
255 (1974); and Keung et al, J. Chem. Educ., 49, 97-100 (1972), all 
disclosures of which are incorporated herein by reference. As is well 
known, the "ene" reaction may be facilitated by the use of a catalyst such 
as aluminum trichloride, alkyl aluminum sesquichloride or the like. To 
form the bifurcated alkyl substituent, the bifurcated alkenyl group of the 
resultant alkenyl-substituted succinic acid compound may be hydrogenated 
to saturate the double bond. 
Similarly suitable alkyl- or alkenylsuccinic acids or anhydrides in which 
the alkyl or alkenyl group is bifurcated on the beta-carbon atom into two 
branches can be formed in analogous fashion using co-dimerized 1-olefin 
such as by co-dimerizing 1-butene and 1-octene, 1-hexene and 1-decene, 
1-pentene and 1-dodecene, 4-methyl-1-pentene and 1-tetradecene, 1-octene 
and 1-decene, 1-nonene and 1-decene, 1-decene and 1-dodecene, 1-dodecene 
and 1-tetradecene, 2,7-dimethyl-1-octene and 1-decene, 
2,7-dimethyl-1-octene and 1-dodecene, 1-tetradecene and 1-pentadecene, 
etc., using a co-dimerization catalyst such as an aluminum alkyl. Such 
co-dimerized olefins are then used in the "ene" reaction in the same 
manner as described above. Hydrogenation of the alkenyl succinic acid 
compound (anhydride, ester, etc.) yields the corresponding bifurcated 
alkyl succinic acid compound. 
The acylating agent may contain polar substituents provided that the polar 
substituents are not present in proportions sufficiently large to alter 
significantly the hydrocarbon character of the acylating agent. Typical 
suitable polar substituents include halo, such as chloro and bromo, oxo, 
oxy, formyl, sulfenyl, sulfinyl, thio, nitro, etc. Such polar 
substituents, if present, preferably do not exceed 10% by weight of the 
total weight of the hydrocarbon portion of the acylating agent, exclusive 
of the carboxyl groups. 
Reference may be had, for example to U.S. Pat. Nos. 3,087,936; 3,163,603; 
3,172,892; 3,219,666; 3,272,746; 3,306,907; 3,346,354; and 4,234,435 for 
synthesis procedures which may be used, or modified for use, in preparing 
the hydrocarbon-substituted succinic acid-type acylating agents with the 
proviso of course that the materials used result in the production of an 
acylating agent containing an average of up to about 50 carbon atoms and 
having an acyclic aliphatic group of at least about 12 but less than 30 
carbon atoms. In the interest of brevity, these patents are incorporated 
herein for their disclosure of suitable synthesis procedures which may be 
adapted for use in producing such succinic acid-type acylating agents. 
As disclosed in the foregoing patents, there are several processes for 
preparing the acids. As utilized in this invention, the process involves 
the reaction of (1) maleic acid, or an acid derivative thereof, e.g., the 
acid halide, or anhydride with (2) an ethylenically unsaturated 
hydrocarbon containing at least about 12 but less than 30 aliphatic carbon 
atoms or a chlorinated hydrocarbon containing at least about 12 but less 
than 30 aliphatic carbon atoms at a temperature within the range of about 
100.degree.-300.degree. C. The chlorinated hydrocarbon or ethylenically 
unsaturated hydrocarbon reactant can, of course, contain polar 
substituents, short chain (e.g., methyl, ethyl, etc.) pendant groups, and 
additional non-conjugated unsaturation. It is these hydrocarbon reactants 
which provide most of the aliphatic carbon atoms present in the acyl 
moiety of the final products. 
When preparing the substituted succinic acid acylating agent according to 
one of these two processes, the maleic acid reactant usually corresponds 
to the formula R'(--COOH).sub.n, where R' is characterized by the presence 
of an ethylenically unsaturated carbon-to-carbon covalent bond and n is 
the integer 2. The acidic reactant can also be the corresponding 
carboxylic acid halide, anhydride, ester, or other equivalent acylating 
agent and mixtures of one or more of these. Ordinarily, the total number 
of carbon atoms in the maleic acid reactant will not exceed 10 and 
generally will not exceed 6. Exemplary acidic reactants are maleic acid, 
maleic anhydride, fumaric acid, methylmaleic acid, methylmaleic anhydride, 
ethylmaleic acid, ethylmaleic anhydride, propylmaleic anhydride, 
butylmaleic anhydride, chloromaleic acid, and the like. Due to 
considerations of economy and availability, the acid reactants usually 
employed are maleic acid and maleic anhydride. 
The substantially saturated aliphatic hydrocarbon-substituted succinic acid 
and anhydrides are especially preferred as acylating agents used as 
starting materials in the present invention. The succinic acid acylating 
agents are readily prepared by reacting maleic anhydride with an olefin or 
a chlorinated hydrocarbon of suitable chain length such as a chlorinated 
polyolefin. The reaction involves merely heating the two reactants at a 
temperature of about 100.degree.-300.degree. C., preferably, 
100.degree.-200.degree. C. The product from such a reaction is a 
substituted succinic anhydride where the substituent is derived from the 
olefin or chlorinated hydrocarbon as described in the above-cited patents. 
The product may be hydrogenated to remove all or a portion of any 
ethylenically unsaturated covalent linkages by standard hydrogenation 
procedure, if desired. The substituted succinic anhydrides may be 
hydrolyzed by treatment with water or steam to the corresponding acid and 
either the anhydride or the acid may be converted to the corresponding 
acid halide or ester by reacting with phosphorus halide, phenols, or 
alcohols. 
The ethylenically unsaturated hydrocarbon reactant and the chlorinated 
hydrocarbon reactant used in the preparation of the acylating agents are 
principally olefins, olefin oligomers, substantially saturated petroleum 
fractions and substantially saturated olefin oligomers and the 
corresponding chlorinated products. They contain an average of from 12 to 
below about 30 carbon atoms in the molecule. The oligomers and chlorinated 
oligomers derived from mono-olefins having from 2 to about 4 carbon atoms 
are preferred. The especially useful oligomers are the oligomers of such 
1-monoolefins as ethylene, propene, 1-butene, and isobutene. Oligomers of 
medial olefins, i.e., olefins in which the olefinic linkage is not at the 
terminal position, likewise are useful. These are exemplified by 2-butene. 
The low molecular weight interoligomers of 1-monoolefins such as 
illustrated above with each other and with other inter-oligomerizable 
olefinic substances are also useful sources of the ethylenically 
unsaturated reactant. Such interoligomers contain an average from 12 to 
below about 30 carbon atoms in the molecule, and include for example, 
those prepared by oligomerizing ethylene with propene, ethylene with 
isobutene, and ethylene with 1-butene, etc. 
The chlorinated hydrocarbons and chlorinated ethylenically unsaturated 
hydrocarbons used in the preparation of the acylating agents also contain 
an average of 12 to below about 30 carbon atoms in the molecule. The 
preferred reactants are the above-described olefins and chlorinated 
olefins containing an average of at least 16 carbon atoms, preferably 
about 16 to about 28 carbon atoms. 
The other reactant used in the formation of the detergents of this 
invention is one or a mixture of alkanol polyamines containing in the 
molecule an average of at least 4 carbon atoms, for example an average in 
the range of 4 to about 50, and preferably from 4 to about 20 carbon 
atoms. Such compounds may be represented by the general formula 
##STR6## 
wherein Z is alkylene of from 1 to about carbon atoms (preferably from 2 
to 4 carbon atoms); each R is independently a hydrogen atom, or (a) a 
hydrocarbyl group, or (b) a hydroxy-substituted hydrocarbyl group, or (c) 
a primary amino-substituted hydrocarbyl group, in which the groups of (a), 
(b), or (c) contain from 1 to about 8 carbon atoms (preferably from 2 to 4 
carbon atoms); and n is 1 to about 10; with the proviso that at least one 
R group is a hydrogen atom such that the compound is co-reactive with the 
carboxylic acylating agent being employed therewith, and the proviso that 
at least one R group is a hydroxy-substituted hydrocarbyl group. 
Preferably the compound contains at least one primary amino group. 
Preferably, n is an integer less than about 6, and the alkylene group (Z) 
is preferably a lower alkylene group such as dimethylene, trimethylene, 
tetramethylene, etc. 
Examples of such alkanol polyamines include alkanol polyamines having at 
least one primary amino group in the molecule such as, for example, 
N-(2-hydroxyethyl)ethylene diamine (also known as 
2-(2-aminoethylamino)ethanol), 2-(2-aminoethylamino)-1-methylethanol, 
2-(2-aminoethylamino)-2-methylethanol, 
2-(2-aminoethylamino)-1-ethylethanol, 
2-(2-aminoethylamino)-2-ethylethanol, 2-(2-aminoethylamino)-1,2-dimethylet 
hanol, N-(2-hydroxyethyl)diethylene triamine, N-(2-hydroxyethyl)triethylene 
tetramine, N-(2 hydroxyethyl)tetraethylene pentamine, 
N-(2-hydroxyethyl)pentaethylene hexamine, 
N-(2-hydroxy-1-methylethyl)diethylene triamine, 
N-(2-hydroxy-2-methylethyl)diethylene triamine, 
N-(2-hydroxy-1-methylethyl)triethylene tetramine, 
N-(2-hydroxy-2-methylethyl)triethylene tetramine, 
N-(2-hydroxy-1-methylethyl)tetraethylene pentamine, 
N-(2-hydroxy-2-methylethyl)tetraethylene pentamine, 
N-(2-hydroxy-1-methylethyl)pentaethylene hexamine, 
N-(2-hydroxy-2-methylethyl)pentaethylene hexamine, 
N-(2-hydroxy-1-butyl)triethylene tetramine, 
N-(1-hydroxy-2-butyl)triethylene tetramine, 
N-(3-hydroxy-2-butyl)triethylene tetramine, 
N-(2-hydroxy-1-butyl)tetraethylene pentamine, 
N-(1-hydroxy-2-butyl)tetraethylene pentamine, 
N-(3-hydroxy-2-butyl)tetraethylene pentamine, 
N-(2-hydroxyethyl)trimethylene diamine, N-(2-hydroxyethyl)tetramethylene 
diamine, N-(2-hydroxyethyl)pentamethylene diamine, 
N-(2-hydroxyethyl)hexamethylene diamine, 
N-(2-hydroxyethyl)tetraminoneopentane, 
N,N'-bis(2-hydroxyethyl)tetraaminoneopentane, 
N,N',N"-tris(2-hydroxyethyl)tetraaminoneopentane, 
N,N-di-(2-hydroxyethyl)ethylene diamine, N-(hydroxymethyl)ethylene 
diamine, N-(8-hydroxyoctyl)ethylene diamine, 
N-(8-hydroxy-2,7-dimethyloctyl)ethylene diamine, and the like. 
The ratio of reactants utilized in the preparation of the compounds of this 
invention may be varied over a wide range. Generally, the reaction mixture 
will contain, for each equivalent (mole) of the acylating agent, at least 
about 0.5 equivalent, and in most cases at least about one equivalent, of 
the alkanol polyamine. In the practice of this invention, the equivalent 
weight of the alkanol polyamine is based on the number of primary amino 
groups per molecule. To illustrate, N-(2-hydroxyethyl)ethylene diamine has 
one equivalent per mole, and N,N'-bis(2-hydroxyethyl)tetraaminoneopentane 
has two equivalents per mole. Thus the former (monoamino) compounds will 
usually be employed in an approximately 1:1 mole ratio with the succinic 
acylating agent. In the case of the latter (diamino) compound, the mole 
ratio of the diamino compound to the succinic acylating agent will usually 
fall in the range of from about 1:1 to about 0.5:1 depending on the extent 
to which it is desired to acylate beyond one of the primary amino groups 
in the diamino compound. 
The temperature of the reaction used to prepare the compounds of this 
invention is not critical, and generally, any temperature from room 
temperature up to the decomposition temperature of any of the reactants or 
the product can be utilized. Preferably, however, the temperature will be 
above about 50.degree. C. and more generally from about 100.degree. C. to 
about 250.degree. C. 
When preparing the dispersant-detergents of this invention, a mixture of 
one or more of the succinic acid-type acylating agents and one or more of 
the alkanol polyamines is heated optionally in the presence of a normally 
liquid, substantially inert organic liquid solvent/diluent. The reaction 
temperature will be, as defined above, generally above 50.degree. C. up to 
the decomposition temperature of any of the reactants or of the product. 
The reaction of the acylating agent with the alkanol polyamine is 
accompanied by the formation of approximately one mole of water for each 
equivalent of the acid used. The removal of water formed may be effected 
conveniently by heating the product at a temperature above 100.degree. C., 
preferably in the neighborhood of about 150.degree. C. Removal of the 
water may be facilitated by blowing the reaction mixture with an inert gas 
such as nitrogen during heating. It may likewise be facilitated by the use 
of a solvent which forms an azeotrope with water. Such solvents are 
exemplified by benzene, toluene, naphtha, n-hexane, xylene, etc. The use 
of such solvents permits the removal of water at a lower temperature, 
e.g., 80.degree. C. 
The compounds of this invention are also useful as detergents for use in 
middle distillate (diesel) fuels to prevent or reduce deposits in fuel 
injectors, in fuel lines, and/or in related parts of the engine. 
Preferably the acyclic aliphatic substituent of the acylating agent for 
the detergents of these compression ignition engine fuel compositions is 
an alkyl or alkenyl group containing from 16 to 18 carbon atoms. 
Octadecenylsuccinic acid or anhydride is a particularly preferred 
acylating agent for making such detergents. Of the various hydroxyalkyl 
polyamines referred to hereinabove, 2-(2-aminoethylamino)ethanol is 
particularly preferred for making the detergents for diesel fuel usage. 
Yet another aspect of this invention is a method for reducing deposits, 
especially carburetor and/or injector deposits, in an internal combustion 
engine, which method comprises: (i) blending with a major amount of a 
liquid hydrocarbon fuel a minor amount of a hydrocarbon-soluble detergent 
of this invention sufficient to reduce the formation of engine deposits, 
the detergent being prepared by reacting (a) at least one 
hydrocarbon-substituted succinic acid or acid derivative containing an 
average of from 16 to about 50 carbon atoms in the molecule and having an 
acyclic aliphatic group containing an average of at least 12 but less than 
30 carbon atoms, with (b) at least one alkanol polyamine containing an 
average of at least 4 carbon atoms; and (ii) using the fuel composition in 
an internal combustion engine.

The following Examples illustrate the preparation of the 
dispersant-detergents of this invention. Unless otherwise indicated in the 
following examples and elsewhere in the specification and claims, all 
parts and percentages are by weight. 
EXAMPLE 1 
To a reactor equipped with a stirrer, a Dean-Stark trap and a condenser are 
added 159 parts of octadecenylsuccinic anhydride and 87 parts of xylene 
(mixed isomers). To this mixture are added 47 parts of 
2-(2-aminoethylamino)ethanol and 52 parts of xylene. The resultant mixture 
is heated to reflux with stirring until all of the water formed in the 
reaction has been collected in the Dean-Stark trap (ordinarily in about 
2.5 hours). The reaction mixture is indicated by infra-red to contain 
succinimide. The product is then stripped to 150.degree. C. at 5 mm Hg 
vacuum. The residue is about 190 parts of predominantly C.sub.18 
alkenylsuccinimide of 2-(2-aminoethylamino)ethanol. Such product may be 
represented by the formula 
##STR7## 
where R' is C.sub.18 alkenyl. 
EXAMPLE 2 
Using the procedure and apparatus as described in Example 1 above, 116 
parts of mixed C.sub.16 - and C.sub.18 -alkenylsuccinic anhydrides 
(average molecular weight of approximately 328) are reacted with 37.3 
parts of 2-(2-aminoethylamino)ethanol in 130 parts of xylene. After the 
stripping operation, approximately 140 parts of product residue is 
recovered. This acylated product is predominantly a mixture of 
succinimides as depicted in Example 1 wherein R' is composed of C.sub.16 
and C.sub.18 alkenyl groups. 
EXAMPLE 3 
To a reactor equipped as in Example 1 above are charged 56 parts of 
branched C.sub.16 -alkenylsuccinic anhydride (in which the alkenyl group 
is formed from dimerized 1-octene) and 52 parts of xylene. Then 16.8 parts 
of 2-(2-aminoethylamino)ethanol and 35 parts of xylene are charged into 
the reactor, and the resultant mixture is heated with stirring to reflux 
while azeotropically removing the water formed during the reaction. After 
collecting 3 parts of water (theory is about 2.8 parts) the product 
mixture is stripped at 35 mm Hg vacuum to 170.degree. C. The residual 
acylated product (approximately 59 parts) is predominantly an 
alkenylsuccinimide of the formula 
##STR8## 
EXAMPLE 4 
To a reactor equipped as in Example 1 above are charged 50 parts of 
branched C.sub.20 -alkenylsuccinic anhydride (in which the alkenyl group 
is formed from dimerized 1-decene) and 35 parts of xylene. Then 14.3 parts 
of 2-(2-aminoethylamino)ethanol and 52 parts of xylene are charged into 
the reactor, and the resultant mixture is heated with stirring to reflux 
while azeotropically removing the water formed during the reaction. After 
collecting about 2.5 parts of water (theory is about 2.4 parts) the 
product mixture is stripped at 35 mm Hg vacuum to 170.degree. C. The 
residual acylated product (approximately 59.9 parts) is predominantly an 
alkenylsuccinimide of the formula 
##STR9## 
EXAMPLE 5 
The procedure of Example 3 above is repeated using 50 parts of a mixture of 
C.sub.16 -, C.sub.18 -, C.sub.20 -, C.sub.22 -, C.sub.24 -, and C.sub.26 
-alkenylsuccinic anhydrides and 15.5 parts of 2-(2-aminoethylamino)ethanol 
in 87 parts of refluxing xylene. The olefin mixture from which this 
alkenyl succinic anhydride reactant is made is composed, on a weight 
basis, of 0.8% C.sub.16 H.sub.32, 8.2% C.sub.18 H.sub.36, 42.2% C.sub.20 
H.sub.40, 33.3% C.sub.22 H.sub.44, 14.7% C.sub.24 H.sub.48 and 0.8% 
C.sub.26 H.sub.52. After stripping the reaction mixture, a product 
composed predominantly of a mixture of C.sub.16-26 -alkenylsuccinimides of 
2-(2-aminoethylamino)ethanol is recovered. The alkenyl groups of this 
succinimide product are in proportions averaging in the range of from 
between about C.sub.20 to about C.sub.22. 
EXAMPLE 6 
Using the general procedure of Example 1 above, a mixture of C.sub.22 - and 
C.sub.24 -alkenylsuccinic anhydrides with an average molecular weight of 
440 and 2-(2-aminoethylamino)ethanol in equimolar quantities are reacted 
in refluxing xylene with removal of by-product water. The product 
remaining after the stripping operation is predominantly an acylated 
compound as depicted in Example 1 above wherein R' is docosenyl (C.sub.22) 
and tetracosenyl (C.sub.24). 
EXAMPLE 7 
By use of the procedure of Example 1 above, 50 parts of a C.sub.18 
alkenyl-substituted succinic anhydride is reacted with 33 parts of 
N-(2-hydroxy-1-methylethyl)tetraethylene pentamine in 100 parts of 
refluxing xylene. The product remaining after the stripping operation is 
predominantly a C.sub.18 alkenylsuccinimide of 
N-(2-hydroxy-1-methylethyl)tetraethylene pentamine. 
EXAMPLE 8 
The procedure of Example 1 above is repeated using 50 parts of a C.sub.12 
alkenyl-substituted succinic anhydride and 48 parts of an equimolar 
mixture of N-(2-hydroxyethyl)diethylene triamine and 
N-(2-hydroxyethyl)triethylene tetramine in 100 parts of refluxing xylene. 
After stripping, a product composed predominantly of a mixture of C.sub.12 
alkenylsuccinimides of N-(2-hydroxyethyl)diethylene triamine and 
N-(2-hydroxyethyl)triethylene tetramine is recovered. 
EXAMPLE 9 
Repetition of the procedure of Example 1 above is done using 159 parts of a 
C.sub.18 alkenyl-substituted succinic anhydride and 73 parts of 
N-(2-hydroxyethyl)hexamethylene diamine in 150 parts of refluxing xylene. 
After stripping, a product composed predominantly of C.sub.18 
alkenylsuccinimide of N-(2-hydroxyethyl)hexamethylene diamine is 
recovered. 
EXAMPLE 10 
Using the same general procedure as in Example 1, N,N'-bis(2-hydroxyethyl) 
tetraaminoneopentane is reacted with a C.sub.28 alkenylsuccinic anhydride 
in refluxing xylene. In one case the reactants are used in a 1.1:1 mole 
ratio (anhydride:aminoneopentane). In another case the reactants are 
employed in a ratio of 1.5 miles of the anhydride per moles of the 
aminoneopentane reactant. In still another case the ratio of the anhydride 
to the aminoneopentane reactant is 2:1. Succinimides with increasing 
proportions of bis substitution are formed in these respective cases. 
EXAMPLE 11 
Hydrogenations at 60.degree.-70.degree. C. and about 30 psi hydrogen 
pressure using palladium on charcoal as catalyst are conducted on products 
made as in Examples 1-10 above yielding corresponding alkyl-substituted 
succinimide products. 
EXAMPLE 12 
By use of the general procedure set forth in Example 1, the following 
compounds are prepared from the alkenyl succinic anhydride in which the 
alkenyl group is a substantially straight chain alkenyl group of the 
appropriate specified chain length: 
C.sub.28 alkenylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.26 alkenylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.24 alkenylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.22 alkenylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.20 alkenylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.18 alkenylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.16 alkenylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.14 alkenylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.12 alkenylsuccinimide of 2-(2-aminoethylamino)ethanol 
EXAMPLE 13 
By use of the general procedure set forth in Example 1, the following 
compounds are prepared from an alkyl-substituted succinic anhydride in 
which the alkyl group is a substantially straight chain alkyl group of the 
appropriate specified chain length: 
C.sub.28 alkylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.26 alkylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.24 alkylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.22 alkylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.20 alkylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.18 alkylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.16 alkylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.14 alkylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.12 alkylsuccinimide of 2-(2-aminoethylamino)ethanol 
EXAMPLE 14 
By use of the general procedure set forth in Example 3, the following 
compounds are prepared from an alkenyl succinic anhydride in which the 
alkenyl group contains the appropriate number of carbon atoms and is 
branched on its beta carbon atom into two branches, one of which contains 
two less carbon atoms than the other: 
C.sub.28 alkenylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.26 alkenylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.24 alkenylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.22 alkenylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.20 alkenylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.18 alkenylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.16 alkenylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.14 alkenylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.12 alkenylsuccinimide of 2-(2-aminoethylamino)ethanol 
EXAMPLE 15 
By use of the general procedure set forth in Example 3, the following 
compounds are prepared from an alkyl-substituted succinic anhydride in 
which the alkyl group contains the appropriate number of carbon atoms and 
is branched on its beta carbon atom into two branches, one of which 
contains two less carbon atoms than the other: 
C.sub.28 alkylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.26 alkylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.24 alkylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.22 alkylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.20 alkylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.18 alkylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.16 alkylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.14 alkylsuccinimide of 2-(2-aminoethylamino)ethanol 
C.sub.12 alkylsuccinimide of 2-(2-aminoethylamino)ethanol 
The effectiveness of the compounds of this invention in reducing carburetor 
deposits was demonstrated by a series of standard CRC carburetor tests. On 
completion of each such engine test the weight of deposits formed on the 
carburetor sleeve during the test was measured. Thus the lower the weight, 
the more effective was the fuel composition. The same base fuel was used 
in each series of tests, and the additives employed therein and results 
obtained are summarized in Tables I-III below. All additive concentrations 
are expressed therein as pounds per thousand barrels (ptb). Baseline runs 
were conducted before and after the runs on the fuels of this invention 
and the values shown in the tables are the averages of such before and 
after runs. 
TABLE I 
______________________________________ 
Additive 
Additive Conc., ptb 
Sleeve Wt., mg 
% Reduction 
______________________________________ 
None -- 27.2 -- 
Ex. 1 10 1.8 93.4 
Ex. 2 10 9.4 65.4 
______________________________________ 
TABLE II 
______________________________________ 
Additive 
Additive Conc., ptb 
Sleeve Wt., mg 
% Reduction 
______________________________________ 
None -- 23.9 -- 
Ex. 1 5 9.4 60.7 
Ex. 2 5 12.7 46.9 
______________________________________ 
TABLE III 
______________________________________ 
Additive 
Additive Conc., ptb 
Sleeve Wt., mg 
% Reduction 
______________________________________ 
None -- 22.5 -- 
Ex. 1 10 2.0 91.1 
Ex. 3 10 3.7 83.6 
Ex. 4 10 2.7 88.0 
Ex. 5 10 3.4 84.9 
Ex. 6 10 5.1 77.3 
______________________________________ 
The amount of the detergent of this invention included in the fuel 
compositions may vary over a wide range although it is preferred not to 
include unnecessarily large excesses of the detergent. The amount included 
in the fuel should be an amount sufficient to improve the desired 
properties such as the prevention and/or reduction in the amount of 
deposits on the various parts of internal combustion engines such as in 
the carburetor and the fuel injector nozzles when the fuel is used to 
operate internal combustion engines. The fuel may contain from about 1 to 
about 10,000, and preferably from about 5 to about 5000 parts per million 
parts by weight of the fuel. The detergents of this invention utilized in 
the fuel compositions are hydrocarbon-soluble in the sense that the 
detergents are at least sufficiently soluble in the hydrocarbon fuel being 
employed to provide a solution containing the desired concentrations 
specified above. 
The fuel compositions can be prepared by adding the detergents of this 
invention to a liquid hydrocarbon fuel, or a concentrate of the detergent 
in a substantially inert, normally liquid organic solvent/diluent such as 
mineral oil, xylene, or a normally liquid fuel as described above can be 
prepared, and the concentrate added to the liquid hydrocarbon fuel. The 
concentrates generally contain about 5-95, usually 10-90% of the detergent 
of the invention, and the concentrate can also contain any of the 
conventional additives for fuels such as those described below. 
In addition to the detergent of this invention, other conventional fuel 
additives can be employed in the fuel compositions and concentrates 
provided by the present invention. Thus, the fuels can contain antiknock 
agents such as tetraalkyllead compounds, organomanganese additives such as 
methylcyclopentadienylmanganese tricarbonyl, lead scavengers such as 
haloalkanes (e.g., ethylene dichloride and ethylene dibromide), deposit 
preventors or modifiers such as trialkyl or triaryl phosphates, dyes, 
antioxidants such as 2,6-di-tert-butyl-4-methyl phenol, rust-inhibitors, 
such as alkylated succinic acids and anhydrides, gum inhibitors, metal 
deactivators, demulsifiers, upper cylinder lubricants, anti-icing agents, 
etc. The middle distillate or diesel fuels may contain ignition 
accelerators such as alkyl nitrates, combustion improvers such as 
methylcyclopentadienylmanganese tricarbonyl, alcohols, corrosion 
inhibitors, antioxidants, stabilizers, particulate reducing additives, and 
the like. 
This invention is susceptible to considerable variation in its practice 
within the spirit and scope of the ensuing claims, the embodiments 
described hereinbefore being illustrative, but not limitative, of its 
practice.