Polyanhydride modified adducts or reactants and oleaginous compositions containing same

An oil soluble dispersant additive useful in oleaginous compositions selected from fuels and lubricating oils comprising the reaction products of: PA1 (i) at least one intermediate adduct comprised of the reaction products of PA2 (a) at least one polyanhydride, and PA2 (b) at least one member selected from the group consisting of polyamines, polyols, and amino alcohols; and PA1 (ii) at least one member selected from the group consisting of PA2 (a) at least one long chain hydrocarbyl substituted C.sub.4 -C.sub.10 dicarboxylic acid producing material; PA2 (b) at least one long chain hydrocarbyl substituted hydroxy aromatic material and at least one aldehyde; or PA2 (c) at least one aldehyde and at least one reaction product of a hydrocarbyl substituted C.sub.3 -C.sub.10 monocarboxylic or C.sub.4 -C.sub.10 dicarboxylic acid or anhydride and an amine substituted hydroxy aromatic compound. Also disclosed are oleaginous compositions, particularly lubricating oil compositions, containing these oil soluble dispersants.

FIELD OF THE INVENTION 
This invention relates to oil soluble dispersant additives useful in 
oleaginous compositions selected from fuel and lubricating oil 
compositions, including concentrates containing said additives, and 
methods for their manufacture and use. The dispersant additives are 
polyanhydride adducts which have been prepared by first reacting a 
polyanhydride with a polyamine, a polyol or an amino alcohol to form an 
intermediate adduct, whereafter the intermediate adduct is reacted with 
(1) a long chain hydrocarbon substituted hydroxy aromatic material such as 
phenol and an aldehyde such as formaldehyde; (2) a mono- or dicarboxylic 
acid, anhydride, ester, etc. which in turn has been substituted with a 
high molecular weight hydrocarbon group; or (3) an aldehyde such as 
formaldehyde and the reaction products formed by reacting long chain 
hydrocarbon substituted mono and dicarboxylic acids or their anhydrides 
with an aminophenol, which may be optionally hydrocarbyl substituted, to 
form a long chain hydrocarbon substituted amide or imide-containing phenol 
intermediate. The high molecular weight hydrocarbon group has a number 
average molecular weight (M.sub.n) of about 500 to about 6,000. The 
additives will have a ratio (functionality) of about 0.7 to 2.0 
dicarboxylic acid producing moieties for each equivalent weight of the 
high molecular weight hydrocarbon therein. 
BACKGROUND OF THE INVENTION 
Multigrade lubricating oils typically are identified by two numbers such as 
10W30, 5W30 etc. The first number in the multigrade designation is 
associated with a maximum low temperature (e.g.-20.degree. C.) viscosity 
requirement for that multigrade oil as measured typically by a cold 
cranking simulator (CCS) under high shear, while the second number in the 
multigrade designation is associated with a minimum high temperature (e.g. 
100.degree. C.) viscosity requirement. Thus, each particular multigrade 
oil must simultaneously meet both strict low and high temperature 
viscosity requirements in order to qualify for a given multigrade oil 
designation. Such requirements are set e.g., by ASTM specifications. By 
"low temperature" as used herein is meant temperatures of typically from 
about -30.degree. to about -5.degree. C. By "high temperature" as used 
herein is meant temperatures of typically at least about 100.degree. C. 
The minimum high temperature viscosity requirement, e.g. at 100.degree. C., 
is intended to prevent the oil from thinning out too much during engine 
operation which can lead to excessive wear and increased oil consumption. 
The maximum low temperature viscosity requirement is intended to 
facilitate engine starting in cold weather and to ensure pumpability, 
i.e., the cold oil should readily flow or slump into the well for the oil 
pump, otherwise the engine can be damaged due to insufficient lubrication. 
In formulating an oil which efficiently meets both low and high temperature 
viscosity requirements, the formulator may use a single oil of desired 
viscosity or a blend of two lubricating oils of different viscosities, in 
conjunction with manipulating the identity and amount of additives that 
must be present to achieve the overall target properties of a particular 
multigrade oil including its viscosity requirements. 
The natural viscosity characteristic of a lubricating oil is typically 
expressed by the neutral number of the oil (e.g. S150N) with a higher 
neutral number being associated with a higher natural viscosity at a given 
temperature. In some instances the formulator will find it desirable to 
blend oils of two different neutral numbers, and hence viscosities, to 
achieve an oil having a viscosity intermediate between the viscosity of 
the components of the oil blend. Thus, the neutral number designation 
provides the formulator with a simple way to achieve a desired base oil of 
predictable viscosity. Unfortunately, merely blending oils of different 
viscosity characteristics does not enable the formulator to meet the low 
and high temperature viscosity requirements of multigrade oils. The 
formulator's primary tool for achieving this goal is an additive 
conventionally referred to as a viscosity index improver (i.e., V.I. 
improver). 
The V. I. improver is conventionally an oil-soluble long chain polymer. The 
large size of these polymers enables them t significantly increase 
Kinematic viscosities of base oils even at low concentrations. However, 
because solutions of high polymers are non-Newtonian they tend to give 
lower viscosities than expected in a high shear environment due to the 
alignment of the polymer. Consequently, V.I. improvers impact (i.e., 
increase) the low temperature (high shear) viscosities (i.e. CCS 
viscosity) of the base oil to a lesser extent than they do the high 
temperature (low shear) viscosities. 
The aforesaid viscosity requirements for a multigrade oil can therefore be 
viewed as being increasingly antagonistic at increasingly higher levels of 
V.I. improver. For example, if a large quantity of V.I. improver is used 
in order to obtain high viscosity at high temperatures, the oil may now 
exceed the low temperature requirement. In another example, the formulator 
may be able to readily meet the requirement for a 10W30 oil but not a 5W30 
oil, with a particular ad-pack (additive package) and base oil. Under 
these circumstances the formulator may attempt to lower the viscosity of 
the base oil, such as by increasing the proportion of low viscosity oil in 
a blend, to compensate for the low temperature viscosity increase induced 
by the V.I. improver, in order to meet the desired low and high 
temperature viscosity requirements. However, increasing the proportion of 
low viscosity oils in a blend can in turn lead to a new set of limitations 
on the formulator, as lower viscosity base oils are considerably less 
desirable in diesel engine use than the heavier, more viscous oils. 
Further complicating the formulator's task is the effect that dispersant 
additives can have on the viscosity characteristics of multigrade oils. 
Dispersants are frequently present in quality oils such as multigrade 
oils, together with the V.I. improver. The primary function of a 
dispersant is to maintain oil insolubles, resulting from oxidation during 
use, in suspension in the oil thus preventing sludge flocculation and 
precipitation. Consequently, the amount of dispersant employed is dictated 
and controlled by the effectiveness of the material for achieving its 
dispersant function. A high quality 10W30 commercial oil might contain 
from two to four times as much dispersant as V.I. improver (as measured by 
the respective dispersant and V.I. improver active ingredients). In 
addition to dispersancy, conventional dispersants can also increase the 
low and high temperature viscosity characteristics of a base oil simply by 
virtue of their polymeric nature. In contrast to the V.I. improver, the 
dispersant molecule is much smaller. Consequently, the dispersant is much 
less shear sensitive, thereby contributing more to the low temperature CCS 
viscosity (relative to its contribution to the high temperature viscosity 
of the base oil) than a V.I. improver. Moreover, the smaller dispersant 
molecule contributes much less to the high temperature viscosity of the 
base oil than the V.I. improver. Thus, the magnitude of the low 
temperature viscosity increase induced by the dispersant can exceed the 
low temperature viscosity increase induced by the V.I. improver without 
the benefit of a proportionately greater increase in high temperature 
viscosity as obtained from a V.I. improver. Consequently, as the 
dispersant induced low temperature viscosity increase causes the low 
temperature viscosity of the oil to approach the maximum low temperature 
viscosity limit, the more difficult it is to introduce a sufficient amount 
of V.I. improver effective to meet the high temperature viscosity 
requirement and still meet the low temperature viscosity requirement. The 
formulator is thereby once again forced to shift to the undesirable 
expedient of using higher proportions of low viscosity oil to permit 
addition of the requisite amount of V.I. improver without exceeding the 
low temperature viscosity limit. 
In accordance with the present invention, dispersants are provided which 
possess inherent characteristics such that they contribute considerably 
less to low temperature viscosity increases than dispersants of the prior 
art while achieving similar or greater high temperature viscosity 
increases. Moreover, as the concentration of dispersant in the base oil is 
increased, this beneficial low temperature viscosity effect becomes 
increasingly more pronounced relative to conventional dispersants. This 
advantage is especially significant for high quality heavy duty diesel 
oils which typically require high concentrations of dispersant additive. 
Furthermore, these improved viscosity properties facilitate the use of 
V.I. improvers in forming multigrade oils spanning a wider viscosity 
requirement range, such as 5W30 oils, due to the overall effect of lower 
viscosity increase at low temperatures while maintaining the desired 
viscosity at high temperatures as compared to the other dispersants. More 
significantly, these viscometric properties also permit the use of higher 
viscosity base stocks with attendant advantages in engine performance. 
Furthermore, the utilization of the dispersant additives of the instant 
invention allows a reduction in the amount of V.I. improvers required. 
The materials of this invention are thus an improvement over conventional 
dispersants because of their effectiveness as dispersants coupled with 
enhanced low temperature viscometric properties. These materials are 
particularly useful with V.I. improvers in formulating multigrade oils. 
SUMMARY OF THE INVENTION 
The present invention is directed to oil soluble dispersant additives 
useful in oleaginous compositions selected from fuels and lubricating oils 
comprising the reaction products of: 
(i) at least one intermediate adduct comprised of the reaction products of 
(a) at least one polyanhydride, and 
(b) at least one member selected from the group consisting of polyamines, 
polyols, and amino alcohols; and 
(ii) at least one member selected from the group consisting of 
(a) long chain hydrocarbon substituted C.sub.3 -C.sub.10 monocarboxylic or 
C.sub.4 -C.sub.10 dicarboxylic acid producing material; 
(b) long chain hydrocarbon substituted hydroxy aromatic material and an 
aldehyde; or 
(c) an aldehyde and reaction products formed by reacting long chain 
hydrocarbyl substituted mono or dicarboxylic acids or their anhydrides 
with an amine substituted hydroxy aromatic compound, e.g., aminophenol, 
which may be optionally hydrocarbyl substituted, to form a long chain 
hydrocarbyl substituted amide or imide-containing hydroxy aromatic 
compound. 
The intermediate adduct (i) is first preformed and this preformed 
intermediate adduct is subsequently reacted with (ii).

DETAILED DESCRIPTION OF THE INVENTION 
In accordance with the present invention there are provided oil soluble 
dispersant compositions. These dispersants exhibit a high temperature to 
low temperature viscosity balance or ratio which is more favorable than 
that of conventional dispersant materials. That is to say the instant 
dispersant materials possess inherent characteristics such that they 
contribute less to low temperature viscosity increase than conventional 
prior art dispersants while increasing the contribution to the high 
temperature viscosity increase. 
The dispersant materials of the instant invention comprise the reaction 
products of 
(i) at least one intermediate adduct comprised of the reaction products of 
(a) at least one polyanhydride, and 
(b) at least one member selected from the group consisting of polyamines, 
polyols, and amino alcohols; and 
(ii) at least one member selected from the group consisting of 
(a) long chain hydrocarbon substituted C.sub.3 -C.sub.10 monocarboxylic or 
C.sub.4 -C.sub.10 dicarboxylic acid producing material; 
(b) long chain hydrocarbon substituted hydroxy aromatic material and an 
aldehyde; or 
(c) an aldehyde such as formaldehyde and reaction products formed by 
reacting long chain hydrocarbyl substituted mono or dicarboxylic acids or 
their anhydrides with an amine substituted hydroxy aromatic compound, 
e.g., aminophenol, which may be optionally hyrocarbyl substituted, to form 
a long chain hydrocarbyl substituted amide or imide-containing hydroxy 
aromatic compound. 
The reaction product (i), also referred to in the specification and 
appended claims as the intermediate adduct, is then reacted with either 
(ii)(a), (ii)(b), or (ii)(c) to form the adduct or dispersant of the 
present invention. If (i)(b) is a polyamine then it contains at least two 
reactive amino groups, one of said amino groups being a primary amino 
group and the other reactive amino group being a primary amino group or a 
secondary amino group. 
In a preferred embodiment of the instant invention (i)(b) is a polyamine, 
and in the following discussion concerning the reaction between (i)(a) and 
(i)(b) to form the intermediate adduct, (i)(b) will be assumed to be such 
a polyamine. 
For purposes of illustration and exemplification only the reaction between 
one mole of a polyanhydride, e.g., a dianhydride, and two moles of a 
polyamine such as tetraethylene pentamine (TEPA) to form the intermediate 
adduct is believed to be represented by the following reaction scheme: 
##STR1## 
This intermediate adduct is then reacted with (ii)(a), (ii)(b), or (ii)(c) 
to form the dispersant of this invention. For purposes of illustration and 
exemplification only if this intermediate adduct is reacted with (ii)(a), 
such as polyisobutenyl succinic anhydride, i.e., 2 moles of 
##STR2## 
where PIB represents polyisobutylene having a number average molecular 
weight of from about 500 to about 6,000, the product is a mixture of 
amides, imides and esters, e.g., 
##STR3## 
Product A is an imide formed by the reaction of both moles of 
polyisobutenyl succinic anhydride (ii)(a) with the primary amino groups of 
the intermediate adduct. Product B is an imide-amide formed by the 
reaction of one mole of polyisobutenyl succinic anhydride (ii)(a) with a 
primary amino group of the intermediate adduct and the reaction of the 
second mole of (ii)(a) with a secondary amino group of the intermediate 
adduct. Product C is formed by the reaction of both moles of (ii)(a) with 
secondary amino groups of the intermediate adduct (i). 
If the intermediate adduct is reacted with (ii)(b) the reaction may be 
represented as follows: 
##STR4## 
ACID PRODUCING MATERIAL 
The long chain hydrocarbon substituted acid producing materials or 
acylating agents which may be reacted with the polyanhydride-polyamine, 
polyanhydride-polyol, and/or polyanhydride-amino alcohol intermediate 
adducts to form the dispersant additives of the instant invention include 
the reaction product of a long chain hydrocarbon polymer, generally a 
polyolefin, with a monounsaturated carboxylic reactant comprising at least 
one member selected from the group consisting of (i) monounsaturated 
C.sub.4 to C.sub.10 dicarboxylic acid wherein (a) the carboxyl groups are 
vicinyl, (i.e. located on adjacent carbon atoms) and (b) at least one, 
preferably both, of said adjacent carbon atoms are part of said mono 
unsaturation; (i) derivatives of (i) such as anhydrides or C.sub.1 to 
C.sub.5 alcohol derived mono- or diesters of (i); (iii) monounsaturated 
C.sub.3 to C.sub.10 monocarboxylic acid wherein the carbon-carbon double 
bond is conjugated to the carboxyl group, i.e., of the structure 
##STR5## 
and (iv) derivatives of (iii) such as C.sub.1 to C.sub.5 alcohol derived 
monoesters of (iii). Upon reaction with the polymer, the monounsaturation 
of the monounsaturated carboxylic reactant becomes saturated. Thus, for 
example, maleic anhydride becomes a polymer substituted succinic 
anhydride, and acrylic acid becomes a polymer substituted propionic acid. 
Typically, from about 0.7 to about 4.0 (e.g., 0.8 to 2.6), preferably from 
about 1.0 to about 2.0, and most preferably from about 1.1 to about 1.7 
moles of said monounsaturated carboxylic reactant are charged to the 
reactor per mole of polymer charged. 
Normally, not all of the polymer reacts with the monounsaturated carboxylic 
reactant and the reaction mixture will contain unreacted polymer. The 
unreacted polymer is typically not removed from the reaction mixture 
(because such removal is difficult and would be commercially infeasible) 
and the product mixture, stripped of any monounsaturated carboxylic 
reactant is employed for further reaction with the amine or alcohol as 
described hereinafter to make the dispersant. 
Characterization of the average number of moles of monounsaturated 
carboxylic reactant (whether it has undergone reaction or not) is defined 
herein as functionality. Said functionality is based upon (i) 
determination of the saponification number of the resulting product 
mixture using potassium hydroxide; and (ii) the number average molecular 
weight of the polymer charged, using techniques well known in the art. 
Functionality is defined solely with reference to the resulting product 
mixture. Although the amount of said reacted polymer contained in the 
resulting product mixture can be subsequently modified, i.e., increased or 
decreased by techniques known in the art, such modifications do not alter 
functionality as defined above. The terms "polymer substituted 
monocarboxylic acid material" as used herein are intended to refer to the 
product mixture whether it has undergone such modifications or not. 
Accordingly, the functionality of the polymer substituted mono- and 
dicarboxylic acid material will be typically at least about 0.5, 
preferably at least about 0.8, and most preferably at least about 0.9 and 
will vary typically from about 0.5 to about 2.8 (e.g., 0.6 to 2), 
preferably from about 0.8 to about 1.4, and most preferably from about 0.9 
to about 1.3. 
Exemplary of such monounsaturated carboxylic reactants are fumaric acid, 
itaconic acid, maleic acid, maleic anhydride chloromaleic acid, 
chloromaleic anhydride, acrylic acid, methacrylic acid, crotonic acid, 
cinnamic acid, and the lower alkyl (e.g., C.sub.1 to C.sub.4 alkyl) acid 
esters of the foregoing, e.g., methyl maleate, ethyl fumarate, methyl 
fumarate, etc. 
The hydrocarbyl substituted mono- or dicarboxylic acid materials, as well 
as methods for their preparation, are well known in the art and are amply 
described in the patent literature. They may be obtained, for example, by 
the Ene reaction between a polyolefin and an alpha-beta unsaturated 
C.sub.4 to C.sub.10 dicarboxylic acid, anhydride or ester thereof, such as 
fumaric acid, itaconic acid, maleic acid, maleic anhydride, chloromaleic 
acid, dimethyl fumarate, etc. 
The hydrocarbyl substituted mono- or dicarboxylic acid materials function 
as acylating agents for the polyepoxide intermediate adduct. 
Preferred olefin polymers for reaction with the unsaturated mono- or 
dicarboxylic acid, anhydride, or ester are polymers comprising a major 
molar amount of C.sub.2 to C.sub.8, e.g. C.sub.2 to C.sub.5, monoolefin. 
Such olefins include ethylene, propylene, butylene, isobutylene, pentene, 
octene-1, styrene, etc. The polymers can be homopolymers such as 
polyisobutylene, as well as copolymers of two or more of such olefins such 
as copolymers of: ethylene and propylene; butylene and isobutylene; 
propylene and isobutylene; etc. Other copolymers include those in which a 
minor molar amount of the copolymer monomers, e.g., 1 to 10 mole %, is a 
C.sub.4 to C.sub.18 non-conjugated diolefin, e.g., a copolymer of 
isobutylene and butadiene; or a copolymer of ethylene, propylene and 
1,4-hexadiene; etc. 
In some cases the olefin polymer may be completely saturated, for example 
an ethylene-propylene copolymer made by a Ziegler-Natta synthesis using 
hydrogen as a moderator to control molecular weight. 
The olefin polymers will usually have number average molecular weights 
(M.sub.n) within the range of about 500 and about 6000, e.g. 700 to 3000, 
preferably between about 800 and about 2500. An especially useful starting 
material for a highly potent dispersant additive made in accordance with 
this invention is polyisobutylene. 
Processes for reacting the olefin polymer with the C.sub.3 -C.sub.10 
unsaturated mono- carboxylic or C.sub.4 -C.sub.10 unsaturated dicarboxylic 
acid, anhydride or ester are known in the art. For example, the olefin 
polymer and the dicarboxylic acid material may be simply heated together 
as disclosed in U.S. Pat. Nos. 3,361,673 and 3,401,118 to cause a thermal 
"ene" reaction to take place. Alternatively, the olefin polymer can be 
first halogenated, for example, chlorinated or brominated to about 1 to 8 
wt. preferably 3 to 7 wt. % chlorine or bromine, based on the weight of 
polymer, by passing the chlorine or bromine through the polyolefin at a 
temperature of 25.degree. to 160.degree. C., e.g., 120.degree. C., for 
about 0.5 to 10, preferably 1 to 7 hours. The halogenated polymer may then 
be reacted with sufficient unsaturated acid or anhydride at 100.degree. to 
250.degree. C., usually about 180.degree. to 220.degree. C., for about 0.5 
to 10 hours, e.g. 3 to 8 hours, so the product obtained will contain an 
average of about 1.0 to 2.0 moles, preferably 1.1 to 1.4 moles, e.g., 1.2 
moles, of the unsaturated acid per mole of the halogenated polymer. 
Processes of this general type are taught in U.S. Pat. Nos. 3,087,436; 
3,172,892; 3,272,746 and others. 
Alternatively, the olefin polymer and the unsaturated acid material are 
mixed and heated while adding chlorine to the hot material. Processes of 
this type are disclosed in U.S. Pat. Nos. 3,215,707; 3,231,587; 3,912,764; 
4,110,349; 4,234,435; and in U.K. No. 1,440,219. 
By the use of halogen, about 65 to 95 wt. % of the polyolefin, e.g. 
polyisobutylene, will normally react with the dicarboxylic acid material. 
Upon carrying out a thermal reaction without the use of halogen or a 
catalyst, then usually only about 50 to 85 wt. % of the polyisobutylene 
will react. Chlorination helps increase the reactivity. For convenience, 
all of the aforesaid functionality ratios of dicarboxylic acid producing 
units to polyolefin, e.g. 1.0 to 2.0, etc. are based upon the total amount 
of polyolefin, that is, the total of both the reacted and unreacted 
polyolefin, present in the resulting product formed in the aforesaid 
reactions. 
THE LONG CHAIN HYDROCARBON SUBSTITUTED HYDROXY AROMATIC MATERIAL 
The hydrocarbyl substituted hydroxy aromatic compounds used in the 
invention include those compounds having the formula 
##STR6## 
wherein a is 1 or 2, R.sup.11 is a long chain hydrocarbon radical, 
R.sup.10 is a hydrocarbon or substituted hydrocarbon radical having from 1 
to about 3 carbon atoms or a halogen radical such as the bromide or 
chloride radical, f is an integer from 1 to 2, c is an integer from 0 to 
2, and d is an integer from 1 to 2. 
Illustrative of such Ar groups are phenylene, biphenylene, naphthylene and 
the like. 
The preferred long chain hydrocarbon substituents of R.sup.11 are olefin 
polymers comprising a major molar amount of at least one C.sub.2 to 
C.sub.10, e.g. C.sub.2 to C.sub.5 monoolefin. Such olefins include 
ethylene, propylene, butylene, pentene, octene-1, styrene, etc. The 
polymers can be homopolymers such as polyisobutylene, as well as 
copolymers of two or more of such olefins such as copolymers of: ethylene 
and propylene; butylene and isobutylene; propylene and isobutylene; etc. 
Other copolymers include those in which a minor molar amount of the 
copolymer monomers, e.g., a copolymer of isobutylene and butadiene; or a 
copolymer of ethylene, propylene and 1,4-hexadiene; etc. 
In some cases, the olefin polymer may be completely saturated, for example 
an ethylene-propylene copolymer made by a Ziegler-Natta synthesis using 
hydrogen as a moderator to control molecular weight. 
The olefin polymers will usually have a number average molecular weight 
(M.sub.n) within the range of about 500 and about 7,000, more usually 
between about 700 and about 3,000. Particularly useful olefin polymers 
have a number average molecular weight within the range of about 800 to 
about 2500, and more preferably within the range of about 850 to about 
1,000 with approximately one terminal double bond per polymer chain. An 
especially useful starting material for a highly potent dispersant 
additive made in accordance with this invention is polyisobutylene. The 
number average molecular weight for such polymers can be determined by 
several known techniques. A convenient method for such determination is by 
gel permeation chromatography (GPC) which additionally provides molecular 
weight distribution information, see W. W. Yau, J. J. Kirkland and D. D. 
Bly, "Modern Size Exclusion Liquid Chromatography", John Wiley and Sons, 
New York, 1979. 
Processes for substituting the hydroxy aromatic compounds with the olefin 
polymer are known in the art and may be depicted as follows: 
##STR7## 
where R.sup.10, R.sup.11, f and c are as previously defined, and BF.sub.3 
is an alkylating catalyst. Processes of this type are described, for 
example, in U.S. Pat. Nos. 3,539,633 and 3,649,229, the disclosures of 
which are incorporated herein by reference. 
Representative hydrocarbyl substituted hydroxy aromatic compounds 
contemplated for use in the present invention include, but are not limited 
to, 2-polypropylene phenol, 3-polypropylene phenol, 4-polypropylene 
phenol, 2-polybutylene phenol, 3-polyisobutylene phenol, 4-polyisobutylene 
phenol, 4-polyisobutylene-2-chlorophenol, 
4-polyisobutylene-2-methylphenol, and the like. 
Suitable hydrocarbyl-substituted polyhydroxy aromatic compounds include the 
polyolefin catechols, the polyolefin resorcinols, and the polyolefin 
hydroquinones, e.g., 4-polyisobutylene-1,2-dihydroxybenzene, 
3-polypropylene-1,2-dihydroxy-benzene, 
5-polyisobutylene-1,3-dihydroxybenzene, 
4-polyamylene-1,3-dihydroxybenzene, and the like. 
Suitable hydrocarbyl-substituted naphthols include 
1-polyisobutylene-5-hydroxynaphthalene, 
1-polypropylene-3-hydroxynaphthalene and the like. 
The preferred long chain hydrocarbyl substituted hydroxy aromatic compounds 
to be used in this invention can be illustrated by the formula: 
##STR8## 
wherein R.sup.12 is hydrocarbyl of from 50 to 300 carbon atoms, and 
preferably is a polyolefin derived from a C.sub.2 to C.sub.10 (e.g., 
C.sub.2 to C.sub.5) mono-alpha-olefin. 
THE ALDEHYDE MATERIAL 
The aldehyde material which can be employed in this invention is 
represented by the formula: 
EQU R.sup.13 CHO 
in which R.sup.13 is a hydrogen or an aliphatic hydrocarbon radical having 
from 1 to 4 carbon atoms. Examples of suitable aldehydes include 
formaldehyde, paraformaldehyde, acetaldehyde and the like. 
POLYAMINES 
Amine compounds useful as reactants with the polyanhydride to form the 
polyanhydride-polyamine intermediate adduct are those containing at least 
two reactive amino groups, i.e., primary and secondary amino groups. They 
include polyalkylene polyamines, of about 2 to 60 (e.g. 2 to 30) , 
preferably 2 to 40, (e.g. 3 to 20) total carbon atoms and about 1 to 12 
(e.g., 2 to 9) , preferably 3 to 12, and most preferably 3 to 9 nitrogen 
atoms in the molecule. These amines may be hydrocarbyl amines or may be 
hydrocarbyl amines including other groups, e.g, hydroxy groups, alkoxy 
groups, amide groups, nitriles, imidazoline groups, and the like. Hydroxy 
amines with 1 to 6 hydroxy groups, preferably 1 to 3 hydroxy groups are 
particularly useful. Such amines should be capable of reacting with the 
acid or anhydride groups of the hydrocarbyl substituted dicarboxylic acid 
moiety and with the anhydride groups of the polyanhydride moiety through 
the amino functionality or a substituent group reactive functionality. 
Since tertiary amines are generally unreactive with anhydrides it is 
desirable to have at least two primary and/or secondary amino groups on 
the amine. It is preferred that the amine contain at least one primary 
amino group, for reaction with the polyanhydride, and at least one 
secondary amino group, for reaction with the acylating agent. Preferred 
amines are aliphatic saturated amines, including those of the general 
formulae: 
##STR9## 
wherein R.sup.IV, R', R'' and R''' are independently selected from the 
group consisting of hydrogen; C.sub.1 to C.sub.25 straight or branched 
chain alkyl radicals; C.sub.1 to C.sub.12 alkoxy C.sub.2 to C.sub.6 
alkylene radicals; C.sub.2 to C.sub.12 hydroxy amino alkylene radicals; 
and C.sub.1 to C.sub.12 alkylamino C.sub.2 to C.sub.6 alkylene radicals; 
and wherein R''' can additionally comprise a moiety of the formula 
##STR10## 
wherein R' is as defined above, and wherein each s and s, can be the same 
or a different number of from 2 to 6, preferably 2 to 4; and t and t' can 
be the same or different and are each numbers of typically from 0 to 10, 
preferably about 2 to 7, most preferably about 3 to 7, with the proviso 
that t+t' is not greater than 10. To assure a facile reaction it is 
preferred that R.sup.IV, R', R'', R''', (s), (s'), (t) and (t') be 
selected in a manner sufficient to provide the compounds of formula Ia 
with typically at least two primary and/or secondary amino groups. This 
can be achieved by selecting at least one of said R.sup.IV, R', R", or 
R''' groups to be hydrogen or by letting (t) in formula Ia be at least one 
when R''' is H or when the (Ib) moiety possesses a secondary amino group. 
The most preferred amines of the above formulas are represented by formula 
Ia and contain at least two primary amino groups and at least one, and 
preferably at least three, secondary amino groups. 
Non-limiting examples of suitable amine compounds include: 
1,2-diaminoethane; 1,3-diaminopropane; 1,4-diaminobutane; 
1,6-diaminohexane; polyethylene amines such as diethylene triamine; 
triethylene tetramine; tetraethylene pentamine; polypropylene amines such 
as 1,2-propylene diamine; di-(1,2-propylene) triamine; di-(1,3-propylene) 
triamine; N,N-dimethyl-1, 3-diaminopropane; N,N-di-(2-aminoethyl) ethylene 
diamine; N-dodecyl-1,3-propane diamine; diisopropanol amine; mono-, di-, 
and tri-tallow amines; amino morpholines such as N-(3-aminopropyl) 
morpholine; and mixtures thereof. 
Other useful amine compounds include: alicyclic diamines such as 
1,4-di(aminoethyl) cyclohexane, and N-aminoalkyl piperazines of the 
general formula: 
##STR11## 
wherein p.sub.1 and p.sub.2 are the same or different and are each 
integers of from 1 to 4, and n.sub.1, n.sub.2 and n.sub.3 are the same or 
different and are each integers of from 1 to 3. 
Commercial mixtures of amine compounds may advantageously be used. For 
example, one process for preparing alkylene amines involves the reaction 
of an alkylene dihalide (such as ethylene dichloride or propylene 
dichloride) with ammonia, which results in a complex mixture of alkylene 
amines wherein pairs of nitrogens are joined by alkylene groups, forming 
such compounds as diethylene triamine, triethylenetetramine, tetraethylene 
pentamine and corresponding piperazines. Low cost poly(ethyleneamine) 
compounds averaging about 5 to 7 nitrogen atoms per molecule are available 
commercially under trade names such as "Polyamine H", "Polyamine 400", 
"Dow Polyamine E-100", etc. 
Useful amines also include polyoxyalkylene polyamines such as those of the 
formulae: 
EQU NH.sub.2 --alkylene--O-alkylene.sub.m --NH.sub.2 (III) 
where m has a value of about 3 to 70 and preferably 10 to 35; and 
EQU R.sup.V --alkylene--O-alkylene.sub.n --NH.sub.2.sbsb.a (IV) 
where n has a value of about 1 to 40, with the provision that the sum of 
all the n's is from about 3 to about 70, and preferably from about 6 to 
about 35, and R.sup.V is a substituted saturated hydrocarbon radical of up 
to 10 carbon atoms, wherein the number of substituents on the R.sup.V 
group is from 3 to 6, and "a" is a number from 3 to 6 which represents the 
number of substituents on R.sup.V. The alkylene groups in either formula 
(III) or (IV) may be straight or branched chains containing about 2 to 7, 
and preferably about 2 to 4 carbon atoms. 
The polyoxyalkylene polyamines of formulas (III) or (IV) above, preferably 
polyoxyalkylene diamines and polyoxyalkylene triamines, may have number 
average molecular weights ranging from about 200 to about 4000 and 
preferably from about 400 to about 2000. The preferred polyoxyalkylene 
polyamines include the polyoxyethylene and polyoxypropylene diamines and 
the polyoxypropylene triamines having average molecular weights ranging 
from about 200 to 2000. The polyoxyalkylene polyamines are commercially 
available and may be obtained, for example, from the Jefferson Chemical 
Company, Inc. under the trade name "Jeffamines D-230, D-400, D-1000, 
D-2000, T-403", etc. 
The polyamine is readily reacted with the polyanhydride, with or without a 
catalyst, simply by heating a mixture of the polyanhydride and polyamine 
in a reaction vessel at a temperature of about 30.degree. C. to about 
200.degree. C., more preferably to a temperature of about 75.degree. C. to 
about 180.degree. C., and most preferably at about 90.degree. C. to about 
160.degree. C., for a sufficient period of time to effect reaction. A 
solvent for the polyanhydride, polyamine and/or intermediate adduct can be 
employed to control viscosity and/or reaction rates. 
Catalysts useful in the promotion of the above-identified 
polyanhydride-polyamine reactions are selected from the group consisting 
of stannous octanoate, stannous hexanoate, stannous oxalate, tetrabutyl 
titanate, a variety of metal organic based catalyst acid catalysts and 
amine catalysts, as described on page 266, and forward in a book chapter 
authorized by R. D. Lundberg and E. F. Cox entitled, "Kinetics and 
Mechanisms of Polymerization: Ring Opening Polymerization", edited by 
Frisch and Reegen, published by Marcel Dekker in 1969, wherein stannous 
octanoate is an especially preferred catalyst. The catalyst is added to 
the reaction mixture at a concentration level of about 50 to about 10,000 
parts of catalyst per one million parts by weight of the total reaction 
mixture. 
POLYOL 
In another aspect of the invention the polyanhydride intermediate adducts 
are prepared by reacting the polyanhydride with a polyol instead of with a 
polyamine. 
Suitable polyol compounds which can be used include aliphatic polyhydric 
alcohols containing up to about 100 carbon atoms and about 2 to about 10 
hydroxyl groups. These alcohols can be quite diverse in structure and 
chemical composition, for example, they can be substituted or 
unsubstituted, hindered or unhindered, branched chain or straight chain, 
etc. as desired. Typical alcohols are alkylene glycols such as ethylene 
glycol, propylene glycol, trimethylene glycol, butylene glycol, and 
polyglycol such as diethylene glycol, triethylene glycol, tetraethylene 
glycol, dipropylene glycol, tripropylene glycol, dibutylene glycol, 
tributylene glycol, and other alkylene glycols and polyalkylene glycols in 
which the alkylene radical contains from two to about eight carbon atoms. 
Other useful polyhydric alcohols include glycerol, monomethyl ether of 
glycerol, pentaerythritol, dipentaerythritol, tripentaerythritol, 
9,10-dihydroxystearic acid, the ethyl ester of 9,10-dihydroxystearic acid, 
3-chloro-1,2propanediol, 1,2-butanediol, 1,4-butanediol, 2,3-hexanediol, 
pinacol, tetrahydroxy pentane, erythritol, arabitol, sorbitol, mannitol, 
1,2-cyclohexanediol, 1,4-cyclohexanediol, 
1,4-(2-hydroxyethyl)-cyclohexane, 1,4-dihydroxy-2-nitrobutane, 
1,4-di-(2-hydroxyethyl)benzene, the carbohydrates such as glucose, 
mannose, glyceraldehyde, and galactose, and the like, copolymers of allyl 
alcohol and styrene, N,N'-di-(2-hydroxylethyl) glycine and esters thereof 
with lower mono-and polyhydric aliphatic alcohols, etc. 
Included within the group of aliphatic alcohols are those alkane polyols 
which contain ether groups such as polyethylene oxide repeating units, as 
well as those polyhydric alcohols containing at least three hydroxyl 
groups, at least one of which has been esterified with a mono-carboxylic 
acid having from eight to about 30 carbon atoms such as octanoic acid, 
oleic acid, stearic acid, linoleic acid, dodecanoic acid, or tall oil 
acid. Examples of such partially esterified polyhydric alcohols are the 
mono-oleate of sorbitol, the mono-oleate of glycerol, the monostearate of 
glycerol, the di-stearate of sorbitol, and the di-dodecanoate of 
erythritol. 
A preferred class of intermediates are those prepared from aliphatic 
alcohols containing up to 20 carbon atoms, and especially those containing 
three to 15 carbon atoms. This class of alcohols includes glycerol, 
erythritol, pentaerythritol, dipentaerythritol, tripentaerythritol, 
gluconic acid, glyceraldehyde, glucose, arabinose, 1,7-heptanediol, 
2,4-heptanediol, 1,2,3-hexanetriol, 1,2,4-hexanetriol, 1,2,5-hexanetriol, 
2,3,4-hexanetriol, 1,2,3-butanetriol, 1,2,4-butanetriol, quinic acid, 
2,2,6,6-tetrakis(hydroxymethyl)-cyclohexanol, 1,10-decanediol, digitalose, 
and the like. The adducts repared from aliphatic alcohols containing at 
least three hydroxyl groups and up to fifteen carbon atoms are 
particularly preferred. 
An especially preferred class of polyhydric alcohols for preparing the 
polyanhydride adducts used as intermediate materials or dispersant 
precursors in the present invention are the polyhydric alkanols containing 
three to 15, especially three to six carbon atoms and having at least 
three hydroxyl groups. Such alcohols are exemplified in the above 
specifically identified alcohols and are represented by glycerol, 
erythritol, pentaerythritol, mannitol, sorbitol, 1,2,4-hexanetriol, and 
tetrahydroxy pentane and the like. 
The polyol is readily reacted with the polyanhydride by heating a mixture 
of the polyol and polyanhydride in a reaction vessel at a temperature of 
about 50.degree. C. to about 200.degree. C., more preferably to a 
temperature of about 75.degree. C. to about 180.degree. C., and most 
preferable at about 90.degree. C. to about 160.degree. C., for a 
sufficient period of time to effect reaction. Optionally, a solvent for 
the polyanhydride, polyol and/or the resulting adduct may be employed to 
control viscosity and/or the reaction rates. 
Catalysts useful in the promotion of the polyanhydride-polyol reactions are 
the same as those which are useful in connection with the 
polyanhydride-polyamine reactions discussed above. The catalyst may be 
added to the reaction mixture at a concentration level of from about 50 to 
about 10,000 parts of catalyst per one million parts by weight of total 
reaction mixture. 
AMINO ALCOHOL 
In a manner analogous to that described for the polyanhydride-polyamine 
reaction and for the polyanhydride-polyol reaction, the polyanhydride can 
be reacted with an amino alcohol to form an intermediate adduct which can 
be further reacted with an acylating agent to form the dispersants of this 
invention. 
Suitable amino alcohol compounds which can be reacted with the 
polyanhydride include those containing up to about 50 total carbon atoms 
and preferably up to about 10 total carbon atoms, from 1 to about 5 
nitrogen atoms, preferably from 1 to 3 nitrogen atoms, and from 1 to about 
15 hydroxyl groups, preferably from about 1 to 5 hydroxyl groups. 
Preferred amino alcohols include the 2,2-disubstituted-2-amino-1-alkanols 
having from two to three hydroxy groups and containing a total of 4 to 8 
carbon atoms. These amino alcohols can be represented by the formula: 
##STR12## 
wherein Z is independently an alkyl or hydroxyalkyl group with the alkyl 
groups having from 1 to 3 carbon atoms wherein at least one, and 
preferably both, of the X substituents is a hydroxyalkyl group of the 
structure -(CH2).sub.n OH, n being 1 to 3. Examples of such amino alcohols 
include: tri-(3-hydroxypropyl) amine; 2-amino-2-methyl-1,3-propanediol; 
2-amino-2-ethyll,3-propanediol; and 
2-amino-2(hydroxymethyl)-1,3-propanediol; the latter also being known as 
THAM or tris(hydroxymethyl) amino methane. THAM is particularly preferred 
because of its effectiveness, availability and low cost. 
The amino alcohol is readily reacted with the polyanhydride by heating a 
mixture of the polyanhydride and amino alcohol in a reaction vessel at a 
temperature of about 50.degree. C. to about 200.degree. C., more 
preferably at temperature of about 75.degree. C. to about 180.degree. C., 
and most preferably at about 90.degree. C. to about 160.degree. C., for a 
sufficient period of time to effect reaction. Optionally, a solvent for 
the polyanhydride, amino alcohol and/or the reaction product may be used 
to control viscosity and/or the reaction rates. 
Catalysts useful in the promotion of the polyanhydride-amino alcohol 
reactions are the same as those which are useful in connection with the 
polyanhydride-polyamine and polyanhydride-polyol reactions, and 
corresponding amounts of catalysts may be employed. 
POLYANHYDRIDES 
The polyanhydrides which are reacted with the aforedescribed polyamines, 
polyols and/or amino alcohols to form the intermediate adducts or 
dispersant precursors of the instant invention are compounds containing at 
least two dicarboxylic acid anhydride moieties. These anhydride moieties 
are connected or joined by polyvalent hydrocarbon moieties or hydrocarbon 
moieties containing at least one hetero atom or group. The hydrocarbon 
moieties generally contain from 1 to about 1,000 carbon atoms, preferably 
from 2 to about 500 carbon atoms. These hydrocarbon moieties may be 
aliphatic, either saturated aliphatic or unsaturated aliphatic, 
cycloaliphatic, aromatic, or aliphatic aromatic. They may be monomeric or 
polymeric, e.g., polyisobutylene, in character. The aliphatic hydrocarbon 
moieties contain from 1 to about 1,000, preferably 2 to about 500, carbon 
atoms. The cycloaliphatic hydrocarbon moieties contain from 4 to about 16 
ring carbon atoms. The ring carbon atoms may contain substituent groups, 
e.g., alkyl groups such as C.sub.1 -C.sub.10 alkyl groups thereon. The 
aromatic hydrocarbon moieties contain from 6 to about 20 ring carbon 
atoms. The aliphatic-aromatic moieties contain from 7 to about 100, 
preferably 7 to about 50, carbon atoms. The hydrocarbon moieties joining 
the anhydride groups may contain substituent groups thereon. The 
substituent groups are those which are substantially inert or unreactive 
at ambient conditions with the anhydride groups. As used in the 
specification and appended claims the term "substantially inert and 
unreactive at ambient conditions" is intended to mean that the atom or 
group is substantially inert to chemical reactions at ambient temperature 
and pressure with the anhydride group so as not to materially interfere in 
an adverse manner with the preparation and/or functioning of the 
compositions, additives, compounds, etc. of this invention in the context 
of its intended use. For example, small amounts of these atoms or groups 
can undergo minimal reaction with the anhydride group without preventing 
the making and using of the invention as described herein. In other words, 
such reaction, while technically discernable, would not be sufficient to 
deter the practical worker of ordinary skill in the art from making and 
using the invention for its intended purposes. Suitable substituent groups 
include, but are not limited to, alkyl groups, hydroxyl groups, tertiary 
amino groups, halogens, and the like. When more than one substituent is 
present they may be the same or different. 
It is to be understood that while many substituent groups are substantially 
inert or unreactive at ambient conditions with the anhydride group they 
will react with the anhydride group under conditions effective to allow 
reaction of the anhydride group with the reactive amino groups of the 
polyamine. Whether these groups are suitable substituent groups which can 
be present on the polyanhydride depends, in part, upon their reactivity 
with the anhydride group. Generally, if they are substantially more 
reactive with the anhydride group than the anhydride group is with the 
reactive amino group, they will tend to materially interfere in an adverse 
manner with the preparation of the dispersants of the present invention 
and may be present on the polyanhydride. An example of such a reactive but 
suitable group is the hydroxyl group. An example of an unsuitable 
substituent group is a primary amino group. 
The hydrocarbon moieties containing at least one hetero atom or group are 
the hydrocarbon moieties described above which contain at least one hetero 
atom or group in the chain. The hetero atom or groups are those that are 
substantially unreactive at ambient conditions with the oxirane rings. 
When more then one hetero atom or group is present they may be the same or 
different. The hetero atoms or groups are preferably separated from the 
anhydride groups by at least one intervening carbon atom. These hetero 
atom or group containing hydrocarbon moieties may contain at least one 
substituent group on at least one carbon atom. These substituent groups 
are the same as those described above as being suitable for the 
hydrocarbon moieties. 
Some illustrative non-limiting examples of suitable hetero atoms or groups 
include: 
oxygen atoms (i.e., --O-- or ether linkages in the carbon chain); 
sulfur atoms (i.e. --S-- or thioether linkages in the carbon chain); 
carboxy groups 
##STR13## 
carbonyl group 
##STR14## 
sulfonyl group 
##STR15## 
sulfinyl group 
##STR16## 
and nitro groups. 
It is critical to the present invention that the polyanhydrides contain at 
least two dicarboxylic acid anhydride moieties on the same molecule. These 
polyanhydrides may be further characterized as polyanhydrides containing 
at least two dicarboxylic acid anhydride moieties joined or connected by a 
hydrocarbon moiety, a substituted hydrocarbon moiety, a hydrocarbon moiety 
containing at least one hetero atom or group, or a substituted hydrocarbon 
moiety containing at least one hetero atom or group. These polyanhydrides 
are well known in the art and are generally commercially available or may 
be readily prepared by conventional and well known methods. 
The polyanhydrides of the instant invention may be represented by the 
formula 
##STR17## 
wherein: b is 0 or 1; 
w is the number of 
##STR18## 
groups present on R, and is at least 2; X is a q valent aliphatic acyclic 
hydrocarbon or substituted hydrocarbon radical containing from 2 to about 
8 carbon atoms which together with the two carbonyl carbon atoms forms a 
cyclic structure, where q is 3 or 4; and 
R is a z valent hydrocarbon radical, substituted hydrocarbon radical, 
hydrocarbon radical containing at least one hetero atom or group, or 
substituted hydrocarbon radical containing at least one hetero atom or 
group, where z=(q-2)w with the proviso that if b=0 then q=4. 
In Formula V, X is independently selected from aliphatic, preferably 
saturated, acylic trivalent or tetravalent hydrocarbon radicals or 
substituted hydrocarbon radicals containing from 1 to about 8 carbon atoms 
which together with the two carbonyl carbon atoms forms a mono-or divalent 
cyclic structure. By trivalent or tetravalent hydrocarbon radicals is 
meant an aliphatic acyclic hydrocarbon, e.g., alkane, which has had 
removed from its carbon atoms three or four hydrogen atoms respectively. 
Some illustrative non-limiting examples of these tri- and tetravalent 
aliphatic acyclic hydrocarbon radicals include: 
##STR19## 
Since two of these valence bonds will be taken up by the two carbonyl 
carbon atoms there will be left one, in the case of x being trivalent, or 
two, in the case of x being tetravelent, valence bonds. Thus, if x is a 
trivalent radical the resulting cyclic structure formed between x and the 
two carbonyl carbon atoms will be monovalent while if x is a tetravalent 
radical the resulting cyclic structure will be divalent. 
When x is a substituted aliphatic, preferably saturated, acyclic tri- or 
tetravalent hydrocarbon radical it contains from 1 to about 4 substituent 
groups on one or more carbon atoms. If more than one substituent group is 
present they may be the same or different. These substituent groups are 
those that do not materially interfere in an adverse manner with the 
preparation and/or functioning of the composition, additives, compounds, 
etc. of this invention in the context of its intended use. Some 
illustrative non-limiting examples of suitable substituent groups include 
alkyl radicals, preferably C.sub.1 to C.sub.5 alkyl radicals; halogens, 
preferably chlorine and bromine, and hydroxyl radicals. However, x is 
preferably unsubstituted. 
When b is zero in Formula V the two carbonyl carbon atoms are bonded 
directly to the R moiety. An illustrative non-limiting example of such a 
case is cyclohexyl dianhydride; i.e., 
##STR20## 
In this cyclohexyl dianhydride R is a tetravalent cycloaliphatic 
hydrocarbon radical, i.e., z=4, with q=4 since b is zero, and w=2. 
In formula V w is an integer of at least 2. The upper limit of w is the 
number of replaceable hydrogen atoms present on R if p is one and x is a 
trivalent radical, or one half the number of replaceable hydrogen atoms 
present on R if p is one and x is a tetravalent radical or if p is zero. 
Generally, however, w has an upper value not greater than about 10, 
preferably about 6, and more preferably about 4. 
R in Formula V is selected from z valent hydrocarbon radicals, substituted 
z valent hydrocarbon radicals, z valent hydrocarbon radicals containing at 
least one hetero atom or group, and z valent substituted hydrocarbon 
radicals containing at least one hetero atom or group. The hydrocarbon 
radicals generally contain from 1 to about 1,000 carbon atoms, preferably 
from 2 to about 50 carbon atoms and may be aliphatic, either saturated or 
unsaturated, cycloaliphatic, aromatic, or aliphatic-aromatic. They may be 
saturated or unsaturated, e.g., contain one or more ethylenic unsaturation 
sites. They may be polymeric or monomeric. An example of a polymeric R is 
polyisobutylene containing from about 40 to about 500 carbon atoms. 
The aliphatic hydrocarbon radicals represented by R are generally those 
containing from 1 to about 1,000, preferably 2 to about 500, carbon atoms. 
They may be straight chain or branched. The cycloaliphatic radicals are 
preferably those containing from 4 to about 16 ring carbon atoms. They may 
contain substituent groups, e.g., lower alkyl groups, on one or more ring 
carbon atoms. These cycloaliphatic radicals include, for example, 
cycloalkylene, cycloalkylidine, cycloalkanetriyl, and cycloalkanetetrayl 
radicals. The aromatic radicals are typically those containing from 6 to 
12 ring carbon atoms. 
It is to be understood that the term "aromatic" as used in the 
specification and the appended claims is not intended to limit the 
polyvalent aromatic moiety represented by R to a benzene nucleus. 
Accordingly it is to be understood that the aromatic moiety can be a 
pyridine nucleus, a thiophene nucleus, a 1,2,3,4-tetrahydronaphthalene 
nucleus, etc., or a polynuclear aromatic moiety. Such polynuclear moieties 
can be of the fused type; that is, wherein at least one aromatic nucleus 
is fused at two points to another nucleus such as found in naphthalene, 
anthracene, the azanaphthalenes, etc. Alternatively, such polynuclear 
aromatic moieties can be of the linked type wherein at least two nuclei 
(either mono- or polynuclear) are linked through bridging linkages to each 
other. Such bridging linkages can be chosen from the group consisting of 
carbon-to-carbon single bonds, ether linkages, keto linkages, sulfide 
linkages, polysulfide linkages of 2 to 6 sulfur atoms, sulfinyl linkages, 
sulfonyl linkages, methylene linkages, alkylene linkages, di-(lower 
alkyl)-methylene linkages, lower alkylene ether linkages, alkylene keto 
linkages, lower alkylene sulfur linkages, lower alkylene polysulfide 
linkages of 2 to 6 carbon atoms, amino linkages, polyamino linkages and 
mixtures of such divalent bridging linkages. 
When the aromatic moiety, Ar, is, for example, a divalent linked 
polynuclear aromatic moiety it can be represented by the general formula 
EQU --Ar--(Lng--Ar)--.sub.w 
wherein w is an integer of 1 to about 10, preferably 1 to about 8, more 
preferably 1, 2 or 3; Ar is a divalent aromatic moiety as described above, 
and each Lng is a bridging linkage individually chosen from the group 
consisting of carbon-to-carbon single bonds, ether linkages (e.g. --O--), 
keto linkages (e.g., 
##STR21## 
sulfide linkages (e.g., --S--), polysulfide linkages of 2 to 6 sulfur 
atoms (e.g., --S.sub.2 --6--), sulfinyl linkages (e.g., --S(O)--), 
sulfonyl linkages (e.g., --S(O)2--), lower alkylene linkages 
##STR22## 
di(lower alkyl) -methylene linkages (e.g., --CR.sup.*.sub.2 --), lower 
alkylene ether linkages (e.g., -- CH.sub.2 -- O--, -- CH.sub.2 -- O -- 
CH.sub.2 --, -- CH.sub.2 -- CH.sub.2 -- O--, 
##STR23## 
etc.) lower alkylene sulfide linkages (e.g., wherein one or more --O--'s 
in the lower alkylene ether linkages is replaced with an --S-- atom), 
lower alkylene polysulfide linkages (e.g., wherein one or more --O--'s is 
replaced with a --S.sub.2 -group). with R* being a lower alkyl group. 
Illustrative of such divalent linked polynuclear aromatic moieties are 
those represented by the formula 
##STR24## 
wherein R.sup.12 and R.sup.13 are independently selected from hydrogen and 
alkyl radicals, preferably alkyl radicals containing from 1 to about 20 
carbon atoms; R.sup.11 is selected from alkylene, alkylidene, 
cycloalkylene, and cycloalkylidene radicals; and u and u.sub.1 are 
independently selected from integers having a value of from 1 to 4. 
The aliphatic-aromatic radicals are those containing from 7 to about 50 
carbon atoms. 
Some illustrative non-limiting examples of polyanhydrides include 
##STR25## 
Included within the scope of the polyanhydrides of the instant invention 
are the dianhydrides. The dianhydrides include those represented by the 
formula 
##STR26## 
wherein: b.sup.2 is 0 or 1; 
b.sup.1 is 0 or 1; 
X.sup.2 is a q.sup.2 valent aliphatic acyclic hydrocarbon radical or 
substituted hydrocarbon radical containing from 1 to about 8 carbon atoms 
which together with the two carbonyl carbon atoms forms a cyclic 
structure, where q.sup.2 is 3 or 4; 
X.sup.1 is a q.sup.1 valent aliphatic acyclic hydrocarbon radical or 
substituted hydrocarbon radical containing from 1 to about 8 carbon atoms 
which together with the two carbonyl carbon atoms form a cyclic structure, 
where q.sup.1 is 3 or 4; 
R.sup.1 is a z.sup.1 valent hydrocarbon radical, substituted hydrocarbon 
radical, hydrocarbon radical containing at least one hetero atom or group, 
or substituted hydrocarbon radical containing at least one hetero atom or 
group, where z.sup.1 =(q.sup.2 +q.sup.1)-4, with the proviso that if 
b.sup.1 is zero than q.sup.2 is 4 and if b.sup.1 is zero than q.sup.1 is 
4. 
X.sup.2 and X.sup.1 are preferably alkanetriyls or alkanetetrayls 
containing from 1 to about 8 carbon atoms. 
R.sup.1 generally contains from 1 to about 100, preferably 2 to about 50, 
carbon atoms and may be a divalent, trivalent, or tetravalent, i.e., 
z.sup.1 is an integer having a value of from 2 to 4 inclusive, hydrocarbon 
radical, substituted hydrocarbon radical, hydrocarbon radical containing 
at least one hetero atom or group, or substituted hydrocarbon radical 
containing at least one hetero atom or group. The hydrocarbon radicals 
represented by R.sup.1 may be aliphatic, either saturated or unsaturated, 
cycloalphatic, aromatic, or aliphatic-aromatic. 
The dianhydrides of Formula VI wherein R is a divalent radical may be 
represented by the Formula 
##STR27## 
wherein: R.sup.2 is a divalent hydrocarbon radical, a substituted divalent 
hydrocarbon radical, a divalent hydrocarbon radical containing at least 
one hetero atom or group, or a substituted divalent hydrocarbon radical 
containing at least one hetero atom or group. 
X.sup.3 is a trivalent aliphatic acyclic hydrocarbon or substituted 
hydrocarbon radical containing from 1 to about 8 carbon atoms which 
together with the two carbonyl carbon atoms forms a cyclic structure; and 
X.sup.4 is a trivalent aliphatic acyclic hydrocarbon or substituted 
hydrocarbon radical containing from 1 to about 8 carbon atoms which 
together with the two carbonyl carbon atoms forms a cyclic structure. 
The divalent hydrocarbon radicals represented by R.sup.2 contain from 1 to 
about 100, preferably 2 to about 50, carbon atoms and include the 
alkylene, alkenylene, cycloalkylene, cycloalkylidene, arylene, alkarylene 
and arylalkenylene radicals. The alkylene radicals contain from 1 to about 
100 carbon, and preferably 2 to about 50, may be straight chain or 
branched. Typical cycloalkylene and cycloalkylidene radicals are there 
containing from 4 to about 16 ring carbon atoms. The cycloalkylene and 
cyclo-alkylidene radicals may contain substituent groups, e.g., lower 
alkyl groups, on one or more ring carbon atoms. When more than one 
substituent group is present they may be the same or different. Typical 
arylene radicals are those containing from 6 to 12 ring carbons, e.g., 
phenylene, naphthylene and biphenylene. Typical alkarylene and aralkylene 
radicals are those containing form 7 to about 50 carbon atoms. 
The substituted divalent hydrocarbon radicals represented by R.sup.2 are 
those divalent hydrocarbon radicals defined above which contain at least 
one substituent group, typically from 1 to about 5 substituent groups, of 
the type described hereinafore. 
The divalent hydrocarbon radicals containing at least one hetero atom or 
group represented by R.sup.1 are those divalent hydrocarbon radicals 
defined above which contain at least one hetero atom or group of the type 
defined hereinafore in the carbon chain. 
Some illustrative non-limiting examples of dianhydrides of Formula VIa 
include 
##STR28## 
The dianhydrides of Formula VI wherein R.sup.1 is a trivalent radical may 
be represented by the formulae 
##STR29## 
wherein: R.sup.3 is a trivalent hydrocarbon radical or a trivalent 
substituted hydrocarbon radical; 
X.sup.5 is a tetravelent aliphatic acyclic hydrocarbon or substituted 
hydrocarbon radical containing form 1 to about 8 carbon atoms which 
together with the carbonyl carbon atoms forms acyclic structure; and 
X.sup.3 is as defined hereinafore. 
The trivalent hydrocarbon radicals represented by R.sup.3 in Formulae Vb 
and Vb.sup.1 are trivalent cycloaliphatic or aromatic hydrocarbon 
radicals. The trivalent cycloaliphatic hydrocarbon radicals represented by 
R.sup.3 preferably contain from 3 to about 16 ring carbon atoms. The 
trivalent aromatic hydrocarbon radicals represented by R.sup.3 are those 
trivalent hydrocarbon radicals described hereinafore which contain at 
least 1, preferably from 1 to about 4, substituent groups of the type 
described hereinafore on the ring carbon atoms. 
The tetravalent aliphatic acyclic hydrocarbon radicals represented by 
X.sup.5 Formula Vb are those containing from 1 to about 8 carbon atoms 
that together with the two carbonyl carbon atoms form a cyclic structure. 
These radicals include the alkanetetrayl radicals. The tetravalent 
substituted aliphatic acylic hydrocarbon radicals represented by X.sup.5 
in Formula VIb are those tetravalent aliphatic acyclic hydrocarbon 
radicals described hereinafore which contain at least one substituent 
group of the type described hereinafore. 
Some illustrative non-limiting examples of the dianhydrides of Formulae VIb 
and VIb.sup.1 include 
##STR30## 
The dianhydrides of Formula VI wherein R' is a tetravalent radical may be 
represented by the formulae 
##STR31## 
wherein: R.sup.4 is a tetravalent hydrocarbon radical or a tetravalent 
substituted hydrocarbon radical; 
X.sup.5 is a tetravalent aliphatic acyclic hydrocarbon or substituted 
hydrocarbon radical containing from 1 to about 8 carbon atoms which 
together with the carbonyl carbon atoms forms a cyclic structure; and 
X.sup.5, is a tetravalent aliphatic acyclic hydrocarbon or substituted 
hydrocarbon radical containing from 1 to about 8 carbon atoms which 
together with the carbonyl carbon atoms forms a cyclic structure. 
The tetravalent hydrocarbon radicals represented by R.sup.4 in Formulae 
VIc-VIc" are tetravalent cycloaliphatic or aromatic hydrocarbon radicals. 
The tetravalent cycloaliphatic or aromatic hydrocarbon radicals preferably 
contain from 4 to about 16 ring carbon atoms. The tetravalent aromatic 
hydrocarbon radicals preferably contain from 6 to 12 ring carbon atoms. 
The tetravalent substituted hydrocarbon radicals represented by R.sup.4 
are these tetravalent hydrocarbon radicals described alone which contain 
at least one substituent group of the type described hereinafore on at 
least one carbon atom. 
Some illustrative non-limiting examples of the dianhydrides of Formulae 
VIc-VIc" include 
##STR32## 
These polyanhydrides are reacted with the polyamines, polyols or amino 
alcohols described hereinafore to produce the intermediate adducts which 
are then reacted with the aforedescribed hydrocarbyl substituted 
dicarboxylic acid producing material or hydrocarbyl substituted hydroxy 
aromatic material and aldehyde to yield the dispersants of the present 
invention. 
The reaction between a polyamine and a polyanhydride to form the 
intermediate polyanhydride-polyamine adduct is described, for the case of 
a dianhydride, in Equation 1 above. In this reaction the different 
anhydride moieties in the same polyanhydride molecule react with the 
primary amino groups on different polyamine molecules to join or link 
together different polyamine molecules via the polyanhydride molecule. 
If a polyanhydride containing more than two dicarboxylic anhydride groups 
per molecule, such as a anhydride, is reacted with a polyamine such as 
TEPA then three molecules of polyamine will be joined or connected 
together by the polyanhydride. This is illustrated by the following 
reaction scheme: 
##STR33## 
If a polyamine containing more than two, e.g., three, primary amino groups, 
per molecule is used then one such polyamine molecule may be linked or 
connected to two other polyamine molecules by three dianhydride molecules. 
In such case the three primary amino groups on each polyamine molecule 
react with anhydride groups on different polyanhydride molecules. 
The chemistry of the polyanhydride-polyamine reaction is such that the 
primary amino functionality in the polyamine is more reactive than the 
secondary amino functionality with the anhydride group of the 
polyanhydride and therefore the product structure A, i.e., imide, 
illustrated in Equations 1 and 2 will be the favored product. It is also 
possible, however, that the secondary amino functionality or the hydroxyl 
functionality of the resulting adduct can react with further molecules of 
the polyanhydride to form a diversity of structures, including structures 
B and C in Equation 1. 
In general the polyanhydride-polyamine intermediate adducts of the present 
invention comprise molecules of polyamines linked to each other by 
polyanhydride molecules. For purposes of illustration and exemplification 
only, and assuming that the polyamine is a polyamine of Formula I and the 
polyanhydride is a dianhydride of Formula V, the polyepoxide-polyamine 
intermediate adduct contains at least one of the following recurring 
structural units 
##STR34## 
wherein R, R''', s and t are as defined hereinafore. 
The stoichiometry of the polyanhydride and polyamine is one of the factors 
that determines the length of the polyanhydride-polyamine adduct, e.g., 
number of recurring structural units of Formula X. Generally, increasing 
the concentration in the reaction mixture of the polyanhydride, up to a 
point where there is present an equivalent amount of anhydride moieties 
per primary amino moieties, results in an increase in the length and 
molecular weight of the intermediate adduct. 
Other factors which influence the length and molecular weight of the adduct 
are reaction times and reaction temperatures. Generally, assuming a fixed 
amount of polyanhydride in the polyanhydride-polyamine reaction mixture, a 
higher reaction temperature and/or a longer reaction time results in 
longer or higher molecular weight intermediate adduct product. 
Reaction between the polyanhydride and polyamine is carried out by adding 
an amount of polyanhydride to the polyamine which is effective to couple 
or link at least some of the polyamine molecules. It is readily apparent 
to those skilled in the art that the amount of polyanhydride utilized 
depends upon a number of factors including (1) the number of reactive, 
e.g., primary, amino groups present in the polyamine, (2) the number of 
anhydride groups present in the polyanhydride, (3) and the number of 
polyamine molecules that it is desired to react, i.e., the degree of 
coupling or chain length of the polyanhydride-polyamine adduct it is 
desired to achieve. 
Generally, however, it is preferred to utilize an amount of polyanhydride 
such that there are present from about 0.01 to 5 equivalents of anhydride 
groups per equivalent of reactive, e.g., primary, amino groups, preferably 
from about 0.1 to 2 equivalents of anhydride groups per equivalent of 
primary amino group. It is preferred, however, that the polyamine be 
present in excess in the polyanhydride-polyamine reaction mixture. 
With appropriate variations to provide for the presence of hydroxyl groups 
the aforedescribed method and discussion for the preparation of the 
polyanhydride-polyamine intermediate adducts is also applicable to the 
polyanhydride-polyol and polyanhydride-amino alcohol adducts. 
REACTION PRODUCTS FORMED BY REACTING LONG CHAIN HYDROCARBON SUBSTITUTED 
MONO OR DICARBOXYLIC ACIDS WITH AMINE SUBSTITUTED HYDROXY AROMATIC 
COMPOUND 
In yet another embodiment of the present invention the dispersants are 
comprised of the reaction products of the intermediate adduct (i), 
preferably one comprised of the reaction products of at least one 
polyanhydride and at least one polyamine, and (ii)(c), i.e., an aldehyde 
such as formaldehyde and reaction products formed by reacting long chain 
hydrocarbyl substituted mono or dicarboxylic acids or their anhydrides of 
the type described hereinafore for (ii)(a) with an amine substituted 
hydroxy aromatic compound, e.g., aminophenol, which may be optionally 
hydrocarbyl substituted, to form a long chain hydrocarbyl substituted 
amide or imide-containing hydroxy aromatic compound. 
Such reaction products of (ii)(c) generally are prepared by reacting about 
1 mole of long chain hydrocarbon substituted mono and dicarboxylic acids 
or their anhydrides with about 1 mole of amine-substituted hydroxy 
aromatic compound (e.g., aminophenol), which aromatic compound can also 
optionally be halogen- or hydrocarbyl-substituted, to form a long chain 
hydrocarbon substituted amide or imidecontaining phenol intermediate (the 
hydrocarbon substituent generally having a number average molecular weight 
of 700 or greater). This hydrocarbyl-substituted amide or imidecontaining 
phenol intermediate is then condensed with the aldehyde and intermediate 
adduct (i) such as polyaminepolyepoxide to form the instant dispersants. 
The amine-substituted hydroxy aromatic compounds can be represented by the 
general formula 
##STR35## 
wherein Ar, R.sup.10, c and d are as defined hereinafore. Preferred amine 
substituted hydroxy aromatic compounds are those wherein d is one. 
The optionally-hydrocarbyl substituted, amine substituted hydroxy aromatic 
compounds used in the preparation of the hydrocarbyl substituted amide or 
imide-containing hydroxy substituted aromatic compound intermediate of 
(ii)(c) include those compounds having the formula: 
##STR36## 
wherein Ar, R.sup.11, R.sup.10, c and d are as defined above. Preferred 
compounds are those wherein d is one. 
Preferred N (hydroxyaryl) amine reactants to be used in forming products 
(ii)(c) for use in this invention are amino phenols of the formula: 
##STR37## 
in which T' is independently hydrogen, an alkyl radical having from 1 to 3 
carbon atoms, or a halogen radical such as the chloride or bromide 
radical. Preferred amino phenols are those wherein T' is hydrogen and/or d 
is one. 
Suitable aminophenols include 2-aminophenol, 3-aminophenol, 4-aminophenol, 
4-amino-3-methylphenol, 4-amino-3-chlorophenol, 4-amino-2-bromophenol and 
4-amino-3-ethylphenol. 
Suitable amino-substituted polyhydroxyaryls are the aminocatechols, the 
amino resorcinols, and the aminohydroquinones, e. g., 4-amino-1,2- 
dihydroxybenzene, 3-amino-1,2-dihydroxybenzene, 
5-amino-1,3-dihydroxybenzene, 4-amino-1,3-dihydroxybenzene, 
2-amino-1,4-dihydroxybenzene, 3-amino-1,4-dihydroxybenzene and the like. 
Suitable aminonaphthols include 1-amino-5-hydroxynaphthalene, 
1-amino-3-hydroxynaphthalene and the like. 
The long chain hydrocarbyl substituted mono- or dicarboxylic acid or 
anhydride materials useful for reaction with the amine-substituted hydroxy 
aromatic compound to prepare the amide or imide intermediates of (ii)(c) 
can comprise any of those described above which are useful in preparing 
the reactant (ii)(a). 
In one preferred aspect of this invention, the intermediates of (ii)(c) are 
prepared by reacting the olefin polymer substituted mono- or dicarboxylic 
acid material with the N-hydroxyaryl amine material to form a 
carbonyl-amino material containing at least one group having a carbonyl 
group bonded to a secondary or a tertiary nitrogen atom. In the amide 
form, the carbonyl-amino material contains --C(O)--NH-- group, and in the 
imide form the carbonyl-amino material will contain --C(O)--N--C(O)-- 
groups. The carbonyl-amino material can therefore comprise N-(hydroxyaryl) 
polymer-substituted dicarboxylic acid diamide, N-(hydroxyaryl) 
polymer-substituted dicarboxylic acid imide, N-(hydroxyaryl) polymer 
substituted-Monocarboxylic acid monoamide, N-(hydroxyaryl) 
polymer-substituted dicarboxylic acid monoamide or a mixture thereof. 
In general, amounts of the olefin polymer substituted mono- or dicarboxylic 
acid material, such as olefin polymer substituted succinic anhydride, and 
of the N-hydroxyaryl amine, such as p-aminophenol which are sufficient to 
provide about one equivalent of acid moiety, i.e., dicarboxylic acid 
moiety, anhydride moiety, or monocarboxylic acid moiety, per equivalent of 
amine moiety, are dissolved in an inert solvent (i.e. a hydrocarbon 
solvent such as toluene, xylene, or isooctane) and reacted at a moderately 
elevated temperature up to the reflux temperature of the solvent used, for 
sufficient time to complete the formation of the intermediate 
N-(hydroxyaryl) hydrocarbyl amide or imide. When an olefin polymer 
substituted monocarboxylic acid material is used, the resulting 
intermediate which is generally formed comprises amide groups. Similarly, 
when an olefin polymer substituted dicarboxylic acid material is used, the 
resulting intermediate generally comprises imide groups, although amide 
groups can also be present in a portion of the carbonyl-amino material 
thus formed. Thereafter, the solvent is removed under vacuum at an 
elevated temperature, generally, at approximately 160.degree. C. 
Alternatively, the intermediate is prepared by combining amounts of the 
olefin polymer substituted mono- or dicarboxylic acid material sufficient 
to provide about one equivalent of dicarboxylic acid moiety, dicarboxylic 
acid anhydride moiety, or monocarboxylic acid moiety per equivalent of 
amine moiety (of the N-(hydroxyaryl) amine) and the N-(hydroxyaryl) amine 
and heating the resulting mixture at elevated temperature under a nitrogen 
purge in the absence of solvent. 
The resulting N-(hydroxyaryl) polymer substituted imides can be illustrated 
by the succinimides of the formula: 
##STR38## 
wherein T' is as defined above, and wherein R.sup.21 is the same as R, as 
defined above e.g., PIB. Similarly, when the olefin polymer substituted 
monocarboxylic acid material is used, the resulting N-(hydroxyaryl) 
polymer substituted amides can be represented by the propionamides of the 
formula: 
##STR39## 
wherein T' and R.sup.21 are as defined above. 
In a second step, the carbonyl-amino intermediate is reacted with an 
aldehyde (e.g., formaldehyde) and the preformed adduct (i), preferably the 
polyamine-polyanhydride adduct, to form the dispersants of the instant 
invention. In general, the reactants are admixed and reacted at an 
elevated temperature until the reaction is complete. This reaction may be 
conducted in the presence of a solvent and in the presence of a quantity 
of mineral oil which is an effective solvent for the finished Mannich base 
dispersant material. This second step can be illustrated by the reaction 
between the above N-(hydroxyphenyl) polymer succinimide intermediate, 
paraformaldehyde and polyamine-polyanhydride adduct, such as that obtained 
by the reaction between 
##STR40## 
in accordance with the following Equation E: 
##STR41## 
wherein a' is an integer of 1 or 2, R.sup.21 and T' are as defined above, 
and D.sup.1 is H or the moiety 
##STR42## 
Similarly, this second step can be illustrated by the Mannich base reaction 
between the above N-(hydroxyphenyl) polymer acrylamide intermediate, 
paraformaldehyde and ethylene-diamine-dianhydride adduct in accordance 
with the following equation F: 
##STR43## 
wherein a' is an integer of 1 or 2, R.sup.21 and T' are as defined above, 
and D.sup.2 is H or the moiety 
##STR44## 
In the reaction of the N-(hydroxyaryl)hydrocarbyl amide or imide 
intermediate with the aldehyde and polyamine-polyanhydride adduct to form 
the dispersants of the instant invention generally an amount of said 
N-(hydroxyaryl)hydrocarbyl amide or imide intermediate sufficient to 
provide one equivalent of hydroxyl moiety is reacted with about 1 to 2.5 
equivalents of aldehyde and an amount of the polyamine-polyanhydride 
adduct (i) sufficient to provide from about 1 to about 30 equivalents of 
reactive amino groups, i.e., primary and secondary amino groups. 
Generally, the reaction of one mole of the carbonyl-amino material, e.g. a 
N-(hydroxyaryl) polymer succinimide or amide intermediate, with two moles 
of aldehyde and one mole of polyamine-polyanhydride adduct will favor 
formation of the products comprising two moieties of amide or imide 
bridged by an -alk-amine-anhydride adduct-alk-group wherein the "alk" 
moieties are derived from the aldehyde (e.g., --CH.sub.2 -- from CH.sub.2 
O) and the "amine-anhydride adduct" moiety is a bivalent bis-N-terminated 
group derived from the reaction of the polyamine and polyanhydride. Such 
products are illustrated by the Equations E and F above wherein a' is one, 
D.sup.1 is the moiety. 
##STR45## 
D.sup.2 is the moiety 
##STR46## 
and wherein T' and R.sup.21 are as defined above. 
In a similar manner, the reaction of substantially equimolar amounts of the 
carbonyl-amino material, aldehyde and polyamine-polyanhydride adduct 
favors the formation of products illustrated by the above Equations E and 
F wherein "a'" is one and D.sup.1 and D.sup.2 are each H, and the reaction 
of one mole of carbonyl-amino material with two moles of aldehyde and two 
moles of the polyamine-polyanhydride adduct permits the formation of 
increased amounts of the products illustrated by Equations E and F wherein 
"a'" is 2 and D.sup.1 and D.sup.2 are each H. 
In order to form the dispersants of the present invention the long chain 
hydrocarbyl substituted mono- or dicarboxylic acid material (ii)(a), the 
long chain hydrocarbon substituted phenol and an aldehyde (ii)(b), or 
aldehyde and reaction product of long chain hydrocarbyl substituted mono- 
or dicarboxylic acid or anhydride and amine-substituted hydroxy aromatic 
compound (ii)(c) is reacted with a polyanhydride-polyamine adduct, a 
polyanhydride-polyol adduct, a polyanhydride-amino alcohol adduct, or a 
mixture thereof. The amounts of polyanhydride adduct and hydrocarbyl 
substituted mono- or dicarboxylic acid material (ii)(a), aldehyde and 
hydrocarbyl substituted hydroxy aromatic compound (ii)(b) or aldehyde and 
reaction product of long chain hydrocarbyl substituted mono- or 
dicarboxylic acid or anhydride and amine-substituted hydroxy aromatic 
compound (ii)(c) utilized in this reaction are amounts which are effective 
to form the dispersants of the instant invention, i.e., dispersant forming 
effective amounts. It will be apparent to those skilled in the art that 
the amount of polyanhydride adduct utilized will depend, in part, upon the 
number of reactive groups (reactive primary amino groups in the 
polyanhydride-polyamine adduct, reactive hydroxyl groups in the 
polyanhydride-polyol adduct, etc.) present in said polyanhydride adduct 
which are available for reaction with, for example, carboxylic acid or 
anhydride groups of the hydrocarbyl substituted dicarboxylic acid 
material. Generally, however, the amount of the polyanhydride adduct is 
such that sufficient polyanhydride adduct is present to provide from about 
0.5 to 15, preferably from about 1 to 10, and more preferably from about 2 
to 4 reactive groups or equivalents, e.g., primary amino groups, for each 
carboxylic acid or anhydride group or equivalent present in the 
hydrocarbyl substituted dicarboxylic acid material (ii)(a) or (ii)(c). 
The reaction conditions under which the reaction between the polyanhydride 
adduct reactant and the hydrocarbyl substituted dicarboxylic acid material 
reactant (ii)(a), aldehyde and hydrocarbyl substituted hydroxy aromatic 
compound reactants (ii)(b) or aldehyde and reaction products of long chain 
hydrocarbyl substituted C.sub.3 -C.sub.10 monocarboxylic or C.sub.4 
-C.sub.10 dicarboxylic acid or anhydride and amine-substituted hydroxy 
aromatic compound and (ii)(c) is carried out are those that are effective 
for coreaction between said reactants to occur. Generally, the reaction 
will proceed at from about 50.degree. to 250.degree. C., preferably 
100.degree. to 210.degree. C. While super-atmospheric pressures are not 
precluded, the reaction generally proceeds satisfactorily at atmospheric 
pressure. The reaction may be conducted using a mineral oil, e.g., 100 
neutral oil, as a solvent. An inert organic co-solvent, e.g., xylene or 
toluene, may also be used. The reaction time generally ranges from about 
0.25 to 24 hours. 
The reaction between the polyanhydride-polyamine adduct and the hydrocarbyl 
substituted dicarboxylic acid material may be exemplified by the following 
reaction scheme which represents the reaction of polyisobutenyl succinic 
anhydride with an alkylene dianhydride/tetraethylene pentamine adduct: 
##STR47## 
The imide reaction product of this reaction may be represented by structure 
A above, while the imide-amide product is represented by structure B and C 
above. 
Alternately, all of the above polyanhydride adducts may be reacted with 
long chain hydrocarbon substituted hydroxy aromatic material and an 
aldehyde (ii)(b). In this embodiment the long chain hydrocarbon 
substituted hydroxy aromatic material and an aldehyde may first be 
prereacted and this reaction product may then be reacted with the 
polyanhydride intermediate adduct. Alternately the polyanhydride 
intermediate adduct, long chain hydrocarbon substituted hydroxy aromatic 
material, and an aldehyde may be reacted substantially simultaneously. In 
general, the amounts of reactants utilized in these reactions are amounts 
which are effective to yield the improved dispersants of the instant 
invention. Generally these amounts are about a molar proportion of long 
chain hydrocarbon substituted hydroxy aromatic material such as long chain 
hydrocarbon substituted hydroxy aromatic material such as long chain 
hydrocarbon substituted phenol, about 1 to about 2.5 moles of aldehyde 
such as formaldehyde, and about 0.5 to 2 moles of polyanhydride adduct. In 
general, the reactants are admixed and reacted at an elevated temperature 
until the reaction is complete. The reaction may be conducted in the 
presence of a solvent and in the presence of a quantity of mineral oil. 
Further aspects of the present invention reside in the formation of metal 
complexes and other post-treatment derivatives, e.g., borated derivatives, 
of the novel additives prepared in accordance with this invention. 
Suitable metal complexes may be formed in accordance with known techniques 
of employing a reactive metal ion species during or after the formation of 
the present C.sub.5 -C.sub.9 lactone derived dispersant materials. 
Complex-forming metal reactants include the nitrates, thiocyanates, 
halides, carboxylates, phosphates, thio-phosphates, sulfates, and borates 
of transition metals such as iron, cobalt, nickel, copper, chromium, 
manganese, molybdenum, tungsten, ruthenium, palladium, platinum, cadmium, 
lead, silver, mercury, antimony and the like. Prior art disclosures of 
these complexing reactions may be found in U.S. Pat. Nos. 3,306,908 and 
Re. No. 26,443. 
Post-treatment compositions include those formed by reacting the novel 
additives of the present invention with one or more post-treating 
reagents, usually selected from the group consisting of boron oxide, boron 
oxide hydrate, boron halides, boron acids, sulfur, sulfur chlorides, 
phosphorous sulfides and oxides, carboxylic acid or anhydride acylating 
agents, anhydrides and episulfides and acrylonitriles. The reaction of 
such post-treating agents with the novel additives of this invention is 
carried out using procedures known in the art. For example, boration may 
be accomplished in accordance with the teachings of U.S. Pat. No. 
3,254,025 by treating the additive compound of the present invention with 
a boron oxide, halide, ester or acid. Treatment may be carried out by 
adding about 1-3 wt. % of the boron compound, preferably boric acid, and 
heating and stirring the reaction mixture at about 135.degree. C. to 
165.degree. C. for 1 to 5 hours followed by nitrogen stripping and 
filtration, if desired. Mineral oil or inert organic solvents facilitate 
the process. 
The compositions produced in accordance with the present invention have 
been found to be particularly useful as fuel and lubricating oil 
additives. 
When the compositions of this invention are used in normally liquid 
petroleum fuels, such as middle distillates boiling from about 150.degree. 
to 800.degree. F. including kerosene, diesel fuels, home heating fuel oil, 
jet fuels, etc., a concentration of the additive in the fuel in the range 
of typically from 0.001 wt. % to 0.5 wt. %, preferably 0.005 wt. % to 0.2 
wt. %, based on the total weight of the composition, will usually be 
employed. These additives can contribute fuel stability as well as 
dispersant activity and/or varnish control behavior to the fuel. 
The compounds of this invention find their primary utility, however, in 
lubricating oil compositions, which employ a base oil in which the 
additives are dissolved or dispersed. Such base oils may be natural or 
synthetic. 
Thus, base oils suitable for use in preparing the lubricating compositions 
of the present invention include those conventionally employed as 
crankcase lubricating oils for spark-ignited and compression-ignited 
internal combustion engines, such as automobile and truck engines, marine 
and railroad diesel engines, and the like. Advantageous results are also 
achieved by employing the additives of the present invention in base oils 
conventionally employed in and/or adapted for use as power transmitting 
fluids such as automatic transmission fluids, tractor fluids, universal 
tractor fluids and hydraulic fluids, heavy duty hydraulic fluids, power 
steering fluids and the like. Gear lubricants, industrial oils, pump oils 
and other lubricating oil compositions can also benefit from the 
incorporation therein of the additives of the present invention. 
Thus, the additives of the present invention may be suitably incorporated 
into synthetic base oils such as alkyl esters of dicarboxylic acids, 
polyglycols and alcohols; polyalpha-olefins, polybutenes, alkyl benzenes, 
organic esters of phosphoric acids, polysilicone oils, etc. selected type 
of lubricating oil composition can be included as desired. 
The additives of this invention are oil-soluble, dissolvable in oil with 
the aid of a suitable solvent, or are stably dispersible materials. 
Oil-soluble, dissolvable, or stably dispersible as that terminology is 
used herein does not necessarily indicate that the materials are soluble, 
dissolvable, miscible, or capable of being suspended in oil in all 
proportions. It does mean, however, that the additives, for instance, are 
soluble or stably dispersible in oil to an extent sufficient to exert 
their intended effect in the environment in which the oil is employed. 
Moreover, the additional incorporation of other additives may also permit 
incorporation of higher levels of a particular polymer adduct hereof, if 
desired. 
Accordingly, while any effective amount of these additives can be 
incorporated into the fully formulated lubricating oil composition, it is 
contemplated that such effective amount be sufficient to provide said lube 
oil composition with an amount of the additive of typically from 0.01 to 
about 10, e.g., 0.1 to 6.0, and preferably from 0.25 to 3.0 wt. %, based 
on the weight of said composition. 
The additives of the present invention can be incorporated into the 
lubricating oil in any convenient way. Thus, they can be added directly to 
the oil by dispersing, or dissolving the same in the oil at the desired 
level of concentration, typically with the aid of a suitable solvent such 
as toluene, cyclohexane, or tetrahydrofuran. Such blending can occur at 
room temperature or elevated. 
Natural base oils include mineral lubricating oils which may vary widely as 
to their crude source, e.g., whether paraffinic, naphthenic, mixed, 
paraffinicnaphthenic, and the like; as well as to their formation, e.g., 
distillation range, straight run or cracked, hydrofined, solvent extracted 
and the like. 
More specifically, the natural lubricating oil base stocks which can be 
used in the compositions of this invention may be straight mineral 
lubricating oil or distillates derived from paraffinic, naphthenic, 
asphaltic, or mixed base crudes, or, if desired, various blends oils may 
be employed as well as residuals, particularly those from which asphaltic 
constituents have been removed. The oils may be refined by conventional 
methods using acid, alkali, and/or clay or other agents such as aluminum 
chloride, or they may be extracted oils produced, for example, by solvent 
extraction with solvents of the type of phenol, sulfur dioxide, furfural, 
dichlorodiethyl ether, nitrobenzene, crotonaldehyde, etc. 
The lubricating oil base stock conveniently has a viscosity of typically 
about 2.5 to about 12, and preferably about 2.5 to about 9 cSt. at 
100.degree. C. 
Thus, the additives of the present invention can be employed in a 
lubricating oil composition which comprises lubricating oil, typically in 
a major amount, and the additive, typically in a minor amount, which is 
effective to impart enhanced dispersancy relative to the absence of the 
additive. Additional conventional additives selected to meet the 
particular requirements of a temperatures. In this form the additive per 
se is thus being utilized as a 100% active ingredient form which can 1 
added to the oil or fuel formulation by the purchase: Alternatively, these 
additives may be blended with suitable oil-soluble solvent and base oil to 
form concentrate, which may then be blended with a lubricating oil base 
stock to obtain the final formulation Concentrates will typically contain 
from about 2 to 80 wt. %, by weight of the additive, and preferably from 
about 5 to 40% by weight of the additive. 
The lubricating oil base stock for the additive of the present invention 
typically is adapted to perform selected function by the incorporation of 
additives therein to form lubricating oil compositions (i.e., 
formulations). 
Representative additives typically present in such formulations include 
viscosity modifiers, corrosion inhibitors, oxidation inhibitors, friction 
modifiers, other dispersants, anti-foaming agents, anti-wear agents, pour 
point depressants, detergents, rust inhibitors and the like. 
Viscosity modifiers impart high and low temperature operability to the 
lubricating oil and permit it to remain shear stable at elevated 
temperatures and also exhibit acceptable viscosity or fluidity at low 
temperatures. These viscosity modifiers are generally high molecular 
weight hydrocarbon polymers including polyesters. The viscosity modifiers 
may also be derivatized to include other properties or functions, such as 
the addition of dispersancy properties. 
These oil soluble viscosity modifying polymers will generally have weight 
average molecular weights of from about 10,000 to 1,000,000, preferably 
20,000 to 500,000, as determined by gel permeation chromatography or light 
scattering methods. 
Representative examples of suitable viscosity modifiers are any of the 
types known to the art including polyisobutylene, copolymers of ethylene 
and propylene, polymethacrylates, methacrylate copolymers, copolymers of 
an unsaturated dicarboxylic acid and vinyl compound, interpolymers of 
styrene and acrylic esters, and partially hydrogenated copolymers of 
styrene/isoprene, styrene/butadiene, and isoprene/butadiene, as well as 
the partially hydrogenated homopolymers of butadiene and isoprene. 
Corrosion inhibitors, also known as anti-corrosive agents, reduce the 
degradation of the metallic parts contacted by the lubricating oil 
composition. Illustrative of corrosion inhibitors are phosphosulfurized 
hydrocarbons and the products obtained by reaction of a phospho-sulfurized 
hydrocarbon with an alkaline earth metal oxide or hydroxide, preferably in 
the presence of an alkylated phenol or of an alkylphenol thioester, and 
also preferably in the presence of an alkylated phenol or of an 
alkylphenol thioester, and also preferably in the presence of carbon 
dioxide. Phosphosulfurized hydrocarbons are prepared by reacting a 
suitable hydrocarbon such as a terpene, a heavy petroleum fraction of a 
C.sub.2 to C.sub.6 olefin polymer such as polyisobutylene, with from 5 to 
30 wt. % of a sulfide of phosphorus for 1/2 to 15 hours, at temperature in 
the range of about 66.degree. to about 316.degree. C. Neutralization of 
the phosphosulfurized hydrocarbon may be effected in the manner taught in 
U.S. Pat. No. 1,969,324. 
Oxidation inhibitors, or antioxidants, reduce the tendency of mineral oils 
to deteriorate in service which deterioration can be evidenced by the 
products of oxidation such as sludge and varnish-like deposits on the 
metal surfaces, and by viscosity growth. Such oxidation inhibitors include 
alkaline earth metal salts of alkyl 
phenolthioesters having preferably C.sub.5 to C.sub.12 alkyl side chains, 
e.g., calcium nonylphenol sulfide, barium toctylphenyl sulfide, 
dioctylphenylamine, phenylalphanaphthylamine, phospho-sulfurized or 
sulfurized hydrocarbons, etc. 
Other oxidation inhibitors or antioxidants useful in this invention 
comprise oil-soluble copper compounds. The copper may be blended into the 
oil as any suitable oilsoluble copper compound. By oil soluble it is meant 
that the compound is oil soluble under normal blending conditions in the 
oil or additive package. The copper compound may be in the cuprous or 
cupric form. The copper may be in the form of the copper dihydrocarbyl 
thio- or dithio-phosphates. Alternatively, the copper may be added as the 
copper salt of a synthetic or natural carboxylic acid. Examples of same 
thus include C.sub.10 to C.sub.18 fatty acids, such as stearic or palmitic 
acid, but unsaturated acids such as oleic or branched carboxylic acids 
such as napthenic acids of molecular weights of from about 200 to 500, or 
synthetic carboxylic acids, are preferred, because of the improved 
handling and solubility properties of the resulting copper carboxylates. 
Also useful are oil-soluble copper dithiocarbamates of the general formula 
(R.sup.20 R.sup.21,NCSS)zCu (where z is 1 or 2, and R.sup.20 and R.sup.21, 
are the same or different hydrocarbyl radicals containing from 1 to 18, 
and preferably 2 to 12, carbon atoms, and including radicals such as 
alkyl, alkenyl, aryl, aralkyl, alkaryl and cycloaliphatic radicals. 
Particularly preferred as R.sup.20 and R.sup.21, groups are alkyl groups 
of from 2 to 8 carbon atoms. Thus, the radicals may, for example, be 
ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, amyl, n-hexyl, 
i-hexyl, n-heptyl, n-octyl, decyl, dodecyl, octadecyl, 2-ethylhexyl, 
phenyl, butylphenyl, cyclohexyl, methylcyclopentyl, propenyl, butenyl, 
etc. In order to obtain oil solubility, the total number of carbon atoms 
(i.e., R.sup.20 and R.sup.21,) will generally be about 5 or greater. 
Copper sulphonates, phenates, and acetylacetonates may also be used. 
Exemplary of useful copper compounds are copper Cu.sup.I and/or Cu.sup.II 
salts of alkenyl succinic acids or anhydrides. The salts themselves may be 
basic, neutral or acidic. They may be formed by reacting (a) polyalkylene 
succinimides (having polymer groups of M.sub.n of 700 to 5,000) derived 
from polyalkylene-polyamines, which have at least one free carboxylic acid 
group, with (b) a reactive metal compound. Suitable rective metal 
compounds include those such as cupric or cuprous hydroxides, oxides, 
acetates, borates, and carbonates or basic copper carbonate. 
Examples of these metal salts are Cu salts of polyisobutenyl succinic 
anhydride, and Cu salts of polyisobutenyl succinic acid. Preferably, the 
selected metal employed is its divalent form, e.g., Cu+2. The preferred 
substrates are polyalkenyl succinic acids in which the alkenyl group has a 
molecular weight greater than about 700. The alkenyl group desirably has a 
M.sub.n from about 900 to 1,400, and up to 2,500, with a M.sub.n of about 
950 being most preferred. Especially preferred is polyisobutylene succinic 
anhydride or acid. These materials may desirably be dissolved in a 
solvent, such as a mineral oil, and heated in the presence of a water 
solution (or slurry) of the metal bearing material. Heating may take place 
between 70.degree. C. and about 200.degree. C. Temperatures of 100.degree. 
C. to 140.degree. C. are entirely adequate. It may be necessary, depending 
upon the salt produced, not to allow the reaction to remain at a 
temperature above about 140.degree. C. for an extended period of time, 
e.g., longer than 5 hours, or decomposition of the salt may occur. 
The copper antioxidants (e.g., Cu-polyisobutenyl succinic anhydride, 
Cu-oleate, or mixtures thereof) will be generally employed in an amount of 
from about 50 to 500 ppm by weight of the metal, in the final lubricating 
or fuel composition. 
Friction modifiers serve to impart the proper friction characteristics to 
lubricating oil compositions such as automatic transmission fluids. 
Representative examples of suitable friction modifiers are found in U.S. 
Pat. No. 3,933,659 which discloses fatty acid esters and amides; U.S. Pat. 
No. 4,176,074 which describes molybdenum complexes of polyisobutyenyl 
succinic anhydride-amino alkanols; U.S. Pat. No. 4,105,571 which discloses 
glycerol esters of dimerized fatty acids; U.S. Pat. No. 3,779,928 which 
discloses alkane phosphonic acid salts; U.S. Pat. No. 3,778,375 which 
discloses reaction products of a phosphonate with an oleamide; U.S. Pat. 
No. 3,852,205 which discloses S-carboxyalkylene hydrocarbyl succinimide, 
S-carboxyalkylene hydrocarbyl succinamic acid and mixtures thereof; U.S. 
Pat. No. 3,879,306 which discloses N(hydroxyalkyl)alkenylsuccinamic acids 
or succinimides: U.S. Pat. No. 3,932,290 which discloses reaction products 
of di- (lower alkyl) phosphites and anhydrides; and U.S. Pat. No. 
4,028,258 which discloses the alkylene oxide adduct of phosphosulfurized 
N-(hydroxyalkyl) alkenyl succinimides. The disclosures of the above 
references are herein incorporated by reference. The most preferred 
friction modifiers are succinate esters, or metal salts thereof, of 
hydrocarbyl substituted succinic acids or anhydrides and thiobis-alkanols 
such as described in U.S. Pat. No. 4,344,853. 
Dispersants maintain oil insolubles, resulting from oxidation during use, 
in suspension in the fluid thus preventing sludge flocculation and 
precipitation or deposition on metal parts. Suitable dispersants include 
high molecular weight alkyl succinimides, the reaction product of 
oil-soluble polyisobutylene succinic anhydride with ethylene amines such 
as tetraethylene pentamine and borated salts thereof. 
Pour point depressants, otherwise known as lube oil flow improvers, lower 
the temperature at which the fluid will flow or can be poured. Such 
additives are well known. Typically of those additives which usefully 
optimize the low temperature fluidity of the fluid are C8-C18 
dialkylfumarate vinyl acetate copolymers, polymethacrylates, and wax 
naphthalene. Foam control can be provided by an antifoamant of the 
polysiloxane type, e.g., silicone oil and polydimethyl siloxane. 
Anti-wear agents, as their name implies, reduce wear of metal parts. 
Representatives of conventional antiwear agents are zinc 
dialkyldithiophosphate and zinc diaryldithiosphate. 
Detergents and metal rust inhibitors include the metal salts of sulphonic 
acids, alkyl phenols, sulfurized alkyl phenols, alkyl salicylates, 
naphthenates and other oil soluble mono- and di-carboxylic acids. Highly 
basic (viz. overbased) metal sales, such as highly basic alkaline earth 
metal sulfonates (especially Ca and Mg salts) are frequently used as 
detergents. Representative examples of such materials, and their methods 
of preparation, are found in co-pending Ser. No. 754,001, filed July 11, 
1985, the disclosure of which is hereby incorporated by reference. 
Some of these numerous additives can provide a multiplicity of effects, 
e.g., a dispersant-oxidation inhibitor. This approach is well known and 
need not be further elaborated herein. 
Compositions when containing these conventional additives are typically 
blended into the base oil in amounts which are effective to provide their 
normal attendant function. Representative effective amounts of such 
additives are illustrated as follows: 
______________________________________ 
Wt. % a.i. Wt. % a.i. 
Additive (Broad) (Preferred) 
______________________________________ 
Viscosity Modifier 
.01-12 .01-4 
Corrosion Inhibitor 
.01-5 .01-1.5 
Oxidation Inhibitor 
.01-5 .01-1.5 
Dispersant .1-20 .1-8 
Pour Point Depressant 
.01-5 .01-1.5 
Anti-Foaming Agents 
.001-3 .001-0.15 
Anti-Wear Agents .001-5 .001-1.5 
Friction Modifiers 
.01-5 .01-1.5 
Detergents/Rust Inhibitors 
.01-10 .01-3 
Mineral Oil Base Balance Balance 
______________________________________ 
When other additives are employed it may be desirable, although not 
necessary, to prepare additive concentrates comprising concentrated 
solutions or dispersions of the dispersant (in concentrate amounts 
hereinabove described), together with one or more of said other additives 
(said concentrate when constituting an additive mixture being referred to 
herein as an additive package) whereby several additives can be added 
simultaneously to the base oil to form the lubricating oil composition. 
Dissolution of the additive concentrate into the lubricating oil may be 
facilitated by solvents and by mixing accompanied with mild heating, but 
this is not essential. The concentrate or additive-package will typically 
be formulated to contain the dispersant additive and optional additional 
additives in proper amounts to provide the desired concentration in the 
final formulation when the additive-package is combined with a 
predetermined amount of base lubricant. Thus, the products of the present 
invention can be added to small amounts of base oil or other compatible 
solvents along with other desirable additives to form additive-packages 
containing active ingredients in collective amounts of typically from 
about 2.5 to about 90%, and preferably from about 5 to about 75%, and most 
preferably from about 8 to about 50% by weight additives in the 
appropriate proportions with the remainder being base oil. 
The final formulations may employ typically about 10 wt. % of the 
additive-package with the remainder being base oil. 
All of said weight percents expressed herein are based on active ingredient 
(a.i.) content of the additive, and/or upon the total weight of any 
additive-package, or formulation which will be the sum of the a.i. weight 
of each additive plus the weight of total oil or diluent. 
This invention will be further understood by reference to the following 
examples, wherein all parts are parts by weight and all molecular weights 
are number weight average molecular weights as noted, and which include 
preferred embodiments of the invention. 
The following example illustrates a dispersant falling outside the scope of 
the instant invention in that no polyanhydride is utilized in the 
preparation of this dispersant. This example is presented for comparative 
purposes only. 
COMATIVE EXAMPLE 1 
Into a reactor vessel are charged, under a nitrogen blanket, 134 grams of 
S150N mineral oil, 4.7 grams (0.05 mole) of tetraethylene pentamine and 
197.84 grams (0.1 mole) of polyisobutylene succinic anhydride (reaction 
product of maleic anhydride and polyisobutylene having a M.sub.n of about 
2,225, said reaction product having a polyisobutylene to succinic 
anhydride ratio of about 1:1.1). The resultant reaction mixture is heated 
at 150.degree. C. and sparged with nitrogen for 3 hours. The oil solution 
containing the product is filtered and the resultant filtered solution of 
the product has a viscosity at 100.degree. C. of 408 centistokes. 
The following example illustrate a dispersant of the instant invention. 
EXAMPLE 
Into a reactor vessel are, charged under a nitrogen blanket, 140 grams of 
S150N mineral oil, 100 cc of toluene, 20 cc of isopropanol 5.4 grams 
(0.025 mole) of paramellitic dianhydride, and 4.7 grams (0.05 mole) of 
tetraethylene pentamine. This reaction mixture is heated at 120.degree. C. 
for one hour. At the end of this one-hour period 197.8 grams (0.1 mole) of 
polyisobutylene succinic anhydride of the type used in Comparative Example 
1 are introduced into the reactor vessel and the resultant reaction 
mixture is heated at 150.degree. C. for 3 hours while sparging with 
nitrogen. The solution containing the product is filtered and the 
resultant filtered solution of the product has a viscosity at 100.degree. 
C. of 750 centistokes. 
As can be seen the viscosity of the oil solution of the dispersant of the 
instant invention (Example 2) is higher than that of the oil solution of 
conventional dispersant of Comparative Example 1.