Treatment of organic compounds to reduce chlorine level

The present invention relates to a process for reducing the chlorine content of an organochlorine compound comprising: introducing into the organochlorine compound, at least one acid selected from the group consisting of Lewis acids, mineral acids other than hydriodic acid and hydrobromic acid, and organic acids having a pKa of less than about 2 to form a mixture, and contacting the organochlorine compound with the at least one acid in the mixture for a sufficient amount of time to reduce the chlorine content of the organochlorine compound. In another embodiment, a process is described for reducing the chlorine content of an organochlorine compound comprising contacting the organochlorine compound with (a) at least one acid selected from the group consisting of Lewis acids, mineral acids other than hydriodic acid and hydrobromic acid, and organic acids having a pKa of less than about 2, and (b) a source of iodine or bromine for a sufficient amount of time to reduce the chlorine content of the organochlorine compound. In other embodiments, the organochlorine compounds may comprise a chlorine-containing polyalkenyl succinic anhydride, and a chlorine-containing reaction product of a polyisobutylene and maleic anhydride prepared in the presence of chlorine. Polyalkenylsuccinic anhydrides treated in accordance with the method of the present invention to reduce the chlorine content thereof may be further reacted with a polyamine or a polyol, or a mixture of a polyamine and a polyol to form the compounds which are useful as dispersants in lubricating oil compositions. Such dispersants and lubricating oil compositions also are described herein.

FIELD OF THE INVENTION 
This invention relates to the treatment of various chlorine-containing 
organic compounds to reduce the level of chlorine in the organic compound. 
The invention has particular utility in preparing compounds for the 
lubricant industry. 
BACKGROUND OF THE INVENTION 
For many years chlorine has been used to facilitate the processing of 
various organic compounds to obtain a variety of useful products. Organic 
compounds whether intentionally incorporating chlorine or by carrying a 
chlorine containing by-product may generate hydrochloric acid upon 
burning. 
Among various halogenated products which are now restricted for production 
or which are being eliminated include materials such as chlorinated 
biphenyl, dioxin, and various ozone depleting materials such as 
chlorofluorocarbons propellants. More innocuous sources of organochlorine 
include products utilized as dispersants in motor oils. A dispersant is a 
compound which aids in keeping sludge from accumulating on engine parts. 
Due to environmental concerns, particularly in Europe, it has become 
desirable to eliminate or reduce the level of chlorine in products no 
matter how small the amount of the chlorine initially. 
One potential solution to eliminating chlorine containing compounds is 
simply not to prepare any compounds in which the chlorine is an ingredient 
or which form a chlorinated by-product. The impracticalities of 
eliminating the production of all chlorine containing compounds worldwide 
should be readily apparent given the large amount of chemical production 
dependent upon the use of chlorine. Products which contain only small 
amounts of organochlorine and in which the chlorine does not impart a 
desired property to the composition may be treated to remove the chlorine. 
Such a process would have to be one which did not cause damage to the 
desired end product. Chlorine is in any event a desirable reactant in the 
chemical industry and is often utilized to promote or cause a faster 
reaction to give the desired end product. 
Thus the present invention deals with methods of treating the organic 
chlorine containing compounds to reduce the chlorine content to acceptably 
low levels. The process may be modified such that the desired composition 
only contains a minor amount of organic chlorine and that the overall 
product's essential characteristics are not changed. In those products 
where the chlorine content is relatively high, the process is conducted to 
convert the underlying organic substrate to a relatively low chlorine 
content by-product. 
The Finkelstein substitution was first described in Ber. 43, 1528 (1910). 
Organic iodide compounds were obtained from the chlorides or bromides by 
treatment with sodium or potassium iodide in acetone solution. It was 
noted by Finkelstein that primary alkyl halides were the most reactive 
compounds and the tertiary were the least reactive. It was further 
observed that the treatment of 1,2-dihalides yields ethylenic derivatives. 
For further information on the Finkelstein substitution see The Merck 
Index An Encyclopedia of Chemicals and Drugs, 8th Edition, 1968. 
U.S. Pat. No. 3,975,271 issued Aug. 17, 1976 to Saunier et al teaches water 
disinfection or sterilization is stated to be typically conducted with 
sodium hypochlorite. A difficulty noted by Saunier et al is that chlorine 
treatment alone often is ineffective due to the chlorine being tied up in 
the form of chloramines. Saunier, et al suggest that bromine and/or iodine 
may be helpful in treating water supplies. 
Ross et al, in U.S. Pat. No. 4,049,382, issued Sep. 20, 1977 discuss a 
method for monitoring total residual chlorine in solution. The process of 
Ross is described as mixing a sample stream with a reagent stream 
containing a disassociated complex of alkali metal ion and iodide ion as 
well as an excess amount of iodide ion. The process is stated to take 
place such that iodide ion reacts with all residual chlorine in the sample 
stream and is converted to iodine. The activity of the iodine is then 
measured in the resultant stream by potentiometric titration. 
The manufacture of various lubricating oil components is discussed in U.S. 
Pat. No. 3,231,587 issued Jan. 25, 1966 to Rense. Similar disclosures are 
found in U.S. Pat. No. 3,215,707 to Rense which issued on Nov. 2, 1965. 
The Rense patents generally discuss a process utilizing chlorine to obtain 
the reaction between a long chain hydrocarbon and maleic anhydride or 
maleic acid. 
More recently, disclosures concerning the production of organo substituted 
maleic anhydride are found in U.S. Pat. No. 4,234,435 issued Nov. 18, 1980 
to Meinhardt et al. 
SUMMARY OF THE INVENTION 
A process for reducing the chlorine content of an organochlorine compound 
is described, and the process comprises: introducing into the 
organochlorine compound, at least one acid selected from the group 
consisting of Lewis acids, mineral acids other than hydriodic acid and 
hydrobromic acid, and organic acids having a pKa of less than about 2 to 
form a mixture, and contacting the organochlorine compound with the at 
least one acid in the mixture for a sufficient amount of time to reduce 
the chlorine content of the organochlorine compound. 
In another embodiment, a process for reducing the chlorine content of an 
organochlorine compound is described which comprises contacting the 
organochlorine compound with (a) at least one acid selected from the group 
consisting of Lewis acids, mineral acids other than hydriodic acid and 
hydrobromic acid, and organic acids having a pKa of less than about 2, and 
(b) a source of iodine or bromine for a sufficient amount of time to 
reduce the chlorine content of the organochlorine compound. 
In other embodiments, the organochlorine compounds may comprise a 
chlorine-containing polyalkenyl succinic anhydride, and a 
chlorine-containing reaction product of a polyisobutylene and maleic 
anhydride prepared in the presence of chlorine. Polyalkenylsuccinic 
anhydrides treated in accordance with the method of the present invention 
to reduce the chlorine content thereof may be further reacted with a 
polyamine or a polyol, or a mixture of a polyamine and a polyol to form 
the compounds which are useful as dispersants in lubricating oil 
compositions. Such dispersants and lubricating oil compositions also are 
described herein. 
DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The term "hydrocarbyl" includes hydrocarbon, as well as substantially 
hydrocarbon, groups. Substantially hydrocarbon describes groups which 
contain non-hydrocarbon substituents which do not alter the predominately 
hydrocarbon nature of the group. 
Examples of hydrocarbyl groups include the following: 
(1) hydrocarbon substituents, that is, aliphatic (e.g., alkyl, alkenyl or 
alkynyl), alicyclic (e.g., cycloalkyl, cycloalkenyl) substituents, 
aromatic-, aliphatic- and alicyclic-substituted aromatic substituents and 
the like as well as cyclic substituents wherein the ring is completed 
through another portion of the molecule (that is, for example, any two 
indicated substituents may together form an alicyclic radical); 
(2) substituted hydrocarbon substituents, that is, those substituents 
containing non-hydrocarbon groups which, in the context of this invention, 
do not alter the predominantly hydrocarbon substituent; those skilled in 
the art will be aware of such groups (e.g., halo (especially chloro and 
fluoro), hydroxy, alkoxy, keto, mercapto, alkylmercapto, nitro, nitroso, 
sulfoxy, etc.); 
(3) hetero substituents, that is, substituents which will, while having a 
predominantly hydrocarbon character within the context of this invention, 
contain other than carbon present in a ring or chain otherwise composed of 
carbon atoms. Suitable heteroatoms will be apparent to those of ordinary 
skill in the art and include, for example, sulfur, oxygen, nitrogen and 
such substituents as, e.g., pyridyl, furyl, thienyl, imidazolyl, etc. In 
general, no more than about 2, preferably no more than one, 
non-hydrocarbon substituent will be present for every 10 carbon atoms in 
the hydrocarbyl group. Often, there will be no such non-hydrocarbon 
substituents in the hydrocarbyl group, and the hydrocarbyl group is purely 
a hydrocarbon group. 
Measurements herein are understood to be approximate. Thus the word "about" 
may be introduced prior to any such measurement in the specification and 
claims. Ranges and ratios may be combined to further describe the 
invention. Temperatures given herein are in degrees Celsius, parts and 
percentages are by weight, and pressures are in kPa gauge unless otherwise 
indicated. Where a ratio of bromine or iodine is expressed to chlorine 
herein, the ratio is in equivalents, e.g. I to Cl. 
It is understood that at least some of the chlorine is chemically 
incorporated in an organic compound (hereafter organochlorine compound or 
chlorine-containing organic compound), and other chlorine may be present 
as a solubilized or otherwise suspended salt. The bromine or iodine used 
herein is in any form capable of generating elemental iodine, hydrogen 
iodide, bromine or hydrogen bromide. 
The invention is particularly useful for lowering the chlorine content of 
chlorinated polymers. Without wishing to be bound by any theory, the 
invention is useful in treating chlorinated compounds such as 
polyisobutylene where the potential exists for the chlorine to be located 
on hindered secondary carbons or on neo primary carbons (a primary carbon 
bonded to a quaternary carbon). It is understood that when referring to 
polyisobutylene that the "pure" hydrocarbon and chlorinated 
polyisobutylene are used interchangeably and when only the chlorinated 
form is meant that the term polyisobutenylchloride is used. Similarly, 
when referring to polyisobutenylsuccinic anhydride, the "pure" anhydride 
and chlorinated polyisobutenylsuccinic anhydride are included, and when 
only the chlorinated form is intended, the term chlorinated 
polyisobutenylsuccinic anhydride is used. 
The present invention, as previously noted, relates to a process for 
treating organochlorine compounds (or chlorine-containing compounds) to 
reduce the chlorine content. A wide variety of organochlorine compounds 
may be treated in accordance with the process of the present invention. 
Simple experimentation under appropriate usage conditions is described 
herein will allow the technician to routinely practice the invention and 
to determine if the process is applicable to particular 
chlorine-containing compounds. 
The organochlorine compounds which may be treated according to the present 
invention in order to reduce the chlorine content thereof may be 
chlorine-containing organic polymeric compounds and mixtures comprising 
chlorine containing organic polymeric compositions. In one embodiment the 
organochlorine compounds treated in accordance with the invention may be 
mixtures comprising a polyalkene-substituted succinic anhydride and 
chlorine which may be free (e.g., Cl.sub.2 or HCl) and/or bonded chlorine 
such as polyalkenyl chloride, chlorinated polyalkenylsuccinic anhydride, 
chlorinated succinic anhydride, etc. In one preferred embodiment the 
organochlorine compounds are polyalkylene succinic anhydrides and in 
particular polyisobutenylsuccinic anhydride mixtures containing up to 
about 20% by weight of polyisobutene and small amounts of free and/or 
bonded chlorine. The polyalkylene succinic anhydrides are often referred 
to as substituted carboxylic or succinic acylating agents. 
The substituted succinic acylating agents can be characterized by the 
presence within their structures of two groups or moieties. The first 
group is referred to hereinafter, for convenience, as the "substituent 
group" and is derived from a polyalkene. The polyalkenes from which the 
substituent groups are derived may be characterized by an Mn (number 
average molecular weight) value of at least about 300. More often the Mn 
value is at least about 900, preferably at least about 1300 up to about 
5000 or even 10,000. In other embodiments, the polyalkenes also can be 
characterized as having Mw/Mn values of from about 1.3 to about 4 or 
higher. 
The second group or moiety of the acylating agent is referred to herein as 
the "succinic group(s)." The succinic group(s) should contain groups which 
can react with alcohols to form esters, ammonia or amines to form imides, 
amides or amine salts, or reactive metals or basically reactive metal 
compounds to form metal salts. 
A preferred chlorine-containing compound which may be treated according to 
the present invention in order to reduce the chlorine content thereof is a 
polyalkylenesuccinic anhydride and in particular a polyisobutenylsuccinic 
anhydride. The preferred compounds have a Mn value of about 1,300 to about 
5,000 and an Mw/Mn value of about 1.5 to about 4. The acylating agent is 
further characterized by having within its structure, at least 1.3 groups 
derived from the dibasic, carboxylic reactant for each equivalent weight 
of the groups derived from the polyalkylene (polyisobutylene). For the 
purpose of convenience, the disclosure of preferred organochlorine 
compounds which may be treated according to the present invention are 
found in U.S. Pat. No. 4,234,435 issued Nov. 18, 1980 to Meinhardt and 
Davis. The entire text of U.S. Pat. No. 4,234,435 is incorporated by 
reference. 
The carboxylic acylating agents containing chlorine which can be treated in 
accordance with the process of the present invention include such agents 
prepared by known processes wherein a polyalkene is reacted with an 
unsaturated dicarboxylic acid or anhydride such as maleic acid or maleic 
anhydride. One method of preparing a succinic acylating agent is 
conveniently designated as the "two-step procedure" and is described in, 
for example, U.S. Pat. No. 3,219,666. It involves first chlorinating the 
polyalkene until there is an average of at least about one chloro group 
for each molecular weight of polyalkene. (For purposes of this invention, 
the molecular weight of the alkene is the weight corresponding to the Mn 
value.) Chlorination involves merely contacting the polyalkene with 
chlorine gas until the desired amount of chlorine is incorporated into the 
chlorinated polyalkene. Chlorination is generally carried out at 
temperatures of about 75.degree. C. to about 125.degree. C. If a diluent 
is used in the chlorination procedure, it should be one which is not 
itself readily subject to further chlorination. Poly- and perchlorinated 
and/or fluorinated alkyl benzenes are examples of suitable diluents. 
The second step in the two-step chlorination procedure is to react the 
chlorinated polyalkene with the maleic reactant at a temperature usually 
within the range of about 100.degree. C. to about 200.degree. C. The mole 
ratio of chlorinated polyalkene to maleic reactant is usually about 1:1. 
(For purposes of making the two-step chlorinated product, a mole of 
chlorinated polyalkene is that weight of chlorinated polyalkene 
corresponding to the Mn value of the unchlorinated polyalkene.) However, a 
stoichiometric excess of maleic reactant can be used, for example, a mole 
ratio of 1:2. 
If an average of more than about one chloro group per molecule of 
polyalkene is introduced during the chlorination step, then more than one 
mole of maleic reactant can react per molecule of chlorinated polyalkene. 
Because of such situations, it is better to describe the ratio of 
chlorinated polyalkene to maleic reactant in terms of equivalents. (An 
equivalent weight of chlorinated polyalkene, for the preparation of a 
two-step chlorinated product, is the weight corresponding to the Mn value 
divided by the average number of chloro groups per molecule of chlorinated 
polyalkene while the equivalent weight of the maleic reactant is its 
molecular weight.) Thus, the ratio of chlorinated polyalkene to maleic 
reactant will normally be such as to provide about one equivalent of 
maleic reactant for each mole of chlorinated polyalkene up to about one 
equivalent of maleic reactant for each equivalent of chlorinated 
polyalkene with the understanding that it is normally desirable to provide 
an excess of maleic reactant; for example, an excess of about 5% to about 
25% by weight. Unreacted excess maleic reactant may be stripped from the 
reaction product, usually under vacuum, or reacted during a further stage 
of the process as explained below. 
The resulting polyalkenyl-substituted succinic acylating agent is, 
optionally, again chlorinated if the desired number of succinic groups are 
not present in the product. If there is present, at the time of this 
subsequent chlorination, any excess maleic reactant from the second step, 
the excess will react as additional chlorine is introduced during the 
subsequent chlorination. Otherwise, additional maleic reactant is 
introduced during and/or subsequent to the additional chlorination step. 
This technique can be repeated until the total number of succinic groups 
per equivalent weight of substituent groups reaches the desired level. 
Another procedure for preparing substituted succinic acid acylating agents 
utilizes a process described in U.S. Pat. No. 3,912,764 and U.K. Patent 
No. 1,440,219, both of which are expressly incorporated herein by 
reference for their teachings in regard to that process. According to that 
process, the polyalkene and the maleic reactant are first reacted by 
heating them together in a "direct alkylation" procedure. When the direct 
alkylation step is completed, chlorine is introduced into the reaction 
mixture to promote reaction of the remaining unreacted maleic reactants. 
According to the patents, 0.3 to 2 or more moles of maleic anhydride are 
used in the reaction for each mole of olefin polymer; i.e. polyalkene. The 
direct alkylation step is conducted at temperatures of 180.degree. C. to 
250.degree. C. During the chlorine-introducing stage, a temperature of 
160.degree. C. to 225.degree. C. is employed. In utilizing this process to 
prepare the substituted succinic acylating agents useful herein, it would 
be necessary to use sufficient maleic reactant and chlorine to incorporate 
at least 1.3 succinic groups into the final product for each equivalent 
weight of groups derived from the polyalkene. 
A further method of preparing a succinic acylating agent is disclosed in 
U.S. Pat. No. 3,231,587 issued Jan. 25, 1966 to Rense which is herein 
incorporated specifically by reference. This process, known as the "one 
step" process, and comprises preparing a mixture of an olefin polymer and 
maleic anhydride, and contacting said mixture at a temperature above about 
140.degree. C. with at least about one mole of chlorine for each mole of 
maleic anhydride. The product of the above process, as indicated before, 
is a hydrocarbon-substituted succinic anhydride, but it is not yet 
established whether the hydrocarbon radical is a saturated radical or one 
having olefinic linkages. The mechanism by which the product is formed is 
likewise not known. It is known, however, that the process is different 
from one in which the olefin polymer is first chlorinated and the 
chlorinated polymer is then allowed to react with maleic anhydride under 
similar reaction conditions. The two-step process requires a considerably 
lengthier reaction time and results in products which are much darker in 
color. Also, if the olefin polymer is to be chlorinated first, the 
chlorination temperature should not be allowed to exceed 120.degree. C. 
Higher temperatures are known to cause dechlorination and thus result in 
products having little or no chlorine. 
To carry out the process, it is preferred that the chlorine be introduced 
into the reaction zone after the olefin polymer has been thoroughly mixed 
with maleic anhydride. If the chlorine is allowed to come into contact 
with the olefin polymer prior to the introduction of maleic anhydride, 
chlorination of the polymer will take place and the advantageous results 
will not be obtained. The rate of introduction of the chlorine is not 
critical. Ordinarily, for maximum utilization of the chlorine used, the 
rate should be about the same as the rate of consumption of chlorine in 
this reaction. 
The minimum temperature at which the reaction of the above process takes 
place at a reasonable rate is about 110.degree. C.; hence, the minimum 
temperature at which the process should be carried out is in the 
neighborhood of 140.degree. C. The preferred temperatures usually range 
between about 160.degree. C. and about 220.degree. C. Higher temperatures 
such as 250.degree. C. or even higher may be used but usually with little 
advantage. The upper limit of the usable temperature is determined 
primarily by the decomposition point of the components in the reaction 
mixture. 
The stoichiometry of the reaction involved in the herein-described process 
requires approximately equimolar amounts of the maleic anhydride and the 
chlorine used. For practical considerations, however, a slight excess, 
usually in the neighborhood of 20-30%, of chlorine is preferred in order 
to offset any accidental loss of this gaseous reactant from the reaction 
mixture. Still greater amounts of chlorine may be used but they do not 
appear to produce any noticeable benefits. 
The relative amounts of the olefin polymer and maleic anhydride will vary 
according to the proportion of the succinic anhydride radicals desired in 
the product. Thus, for each mole of the polymer employed, one or more 
moles of maleic anhydride may be used depending upon whether one or more 
succinic anhydride radicals are to be incorporated in each polymer 
molecule. In general, the higher the molecular weight of the polymer, the 
greater the proportion of maleic anhydride which may be used. On the other 
hand, when a molar excess of the polymer reactant is used, the excess 
polymer will simply remain in the product as a diluent without any adverse 
effect. 
As indicated previously the process of this invention is applicable to the 
treatment of hydrocarbon substituted succinic anhydride derived from 
olefin polymers. The olefin polymers include principally the homopolymers 
and copolymers of lower mono-olefin, i.e., ethylene, propene, isobutene, 
and n-butene. Copolymers of the above-illustrated lower mono-olefins with 
copolymerizable higher mono-olefins or diolefins such as hexene, 
cyclohexene, butadiene, isoprene, chloroprene, etc. are likewise 
contemplated for use herein, provided that the lower mono-olefin units 
comprise at least 90-95 % by weight of the polymer. The copolymers may be 
exemplified by copolymers of 99% of isobutene with 1% of butadiene, 
copolymers of 95 % of isobutene with 5 % of styrene, copolymers of 98% of 
propene with 2% of piperylene, terpolymers of 98% of isobutene with 1% of 
piperylene and 1% of propene, etc. For the most part, polymers of 
isobutene are preferred for reasons of their ready availability and the 
particular utility of the products obtained therefrom. The molecular 
weights of the polymers contemplated for use herein may vary within broad 
limits such as from about 100 to about 50,000 or even higher. 
In one embodiment, the chlorine content of the chlorine-containing 
compounds is reduced in accordance with the process of the present 
invention by contacting the chlorine-containing compound with at least one 
acid selected from the group consisting of Lewis acids, mineral acids 
other than hydriodic acid and hydrobromic acid, and organic acids having a 
pKa of less than about 2 for a period of time sufficient to reduce the 
chlorine content of the organochlorine compound. 
A wide variety of Lewis acids are useful in the process of the present 
invention. Various compounds of zinc, magnesium, calcium, iron, copper, 
boron, aluminum, tin and titanium are useful Lewis acids. Examples of zinc 
compounds useful as well as Lewis acids in the process of the present 
invention includes zinc acetate, zinc oleate, zinc bromide, zinc chloride, 
zinc iodide, zinc oxide and zinc sulfate. Examples of iron compounds 
include ferrous acetate, ferric acetate, ferrous bromide, ferric bromide, 
ferrous chloride, ferric chloride, ferrous iodide and ferric iodide. 
Examples of magnesium compounds include magnesium iodide and magnesium 
sulfate. Calcium compounds such as calcium iodide and calcium sulfate are 
useful. Examples of copper compounds include cuprous oxide, cuprous 
chloride cupric acetate, cupric bromide, cupric chloride, cupric iodide, 
cupric oxide, cupric sulfate and cupric sulfide. Examples of boron 
compounds include boron trifluoride, boron trichloride, boron tribromide, 
trimethylborane, triethylborane, trimethylborate, triethylborate, 
triisopropylborate and tributylborate. Examples of aluminum compounds 
include trialkylaluminum compounds such trimethylaluminum, 
triethylaluminum and triisobutylaluminum; aluminum alkoxides such as 
aluminum isopropoxides, aluminum sec-butoxides and aluminum t-butoxides; 
aluminum halides such as aluminum fluorides, aluminum chlorides and 
aluminum bromides; and aluminum oxide. Examples of tin compounds include 
the stannous and stannic forms of tin acetate, tin bromide, tin chloride, 
tin iodide and tin sulfate. Examples of titanium compounds include 
titanium (IV) chloride, titanium (IV) isopropoxide, titanium (IV) 
isobutoxide and titanium (IV) ethoxide and titanium oxides. Any of the 
above Lewis acids may be converted to other Lewis acids under the process 
conditions. For example, zinc oxide may be converted to zinc chloride by 
reaction with chlorine or hydrogen chloride present in the organochlorine 
compound, or the zinc oxide may be converted to zinc iodide by reaction 
with the source of iodine added to the reaction mixture. Lewis acids may 
also be formed in situ by adding to the reaction mixtures, metals such as 
magnesium, aluminum, zinc, etc. Other examples of Lewis acids which may be 
utilized include ethyl ethylenetetracarboxylate and tetracyanoethylene. 
Mineral acids, other than hydriodic acid and hydrobromic acid which may be 
utilized in the present invention include strong mineral acids such as 
sulfuric acid, nitric acid, phosphoric acid, pyrophosphorus acid, 
hypoiodus acid, etc. The acid also may be a strong organic acid such as 
organic acids having a pKa of less than about 2. Examples of such acids 
include aliphatic and aromatic sulfonic acids such as methane sulfonic 
acid, trifluoromethyl sulfonic acid, benzene sulfonic acid, various 
p-alkylbenzene sulfonic acids, p-toluene sulfonic acid, and naphthalene 
sulfonic acid; carboxylic acids such as cyclopropane-1,1-dicarboxylic 
acid, nitroacetic acid, dichloroacetic acid, maleic acid, oxalic acid, 
picric acid, trichloroacetic acid, trifluoroacetic acid, trihydroxybenzoic 
acid; phenolic compounds such as trinitrophenol; and phosphonic acids such 
as phenyl phosphonic acid, methyl phosphonic acid and trifluoromethyl 
phosphonic acid. 
Mixtures of any of the above-described acids can be utilized in the process 
of the present invention. For example, mixtures of Lewis acids, a mixture 
of a Lewis acid and a mineral acid, and a mixture of a Lewis acid and an 
organic acid may be utilized in the process of the present invention. In 
one embodiment, a mixture of a zinc salt and an iron salt has been found 
to be useful. When a mixture of acids is utilized in the process of the 
present invention, the acids can be added as a mixture, or the acids can 
be added to the organochlorine compound sequentially and in any order. 
The amount of the at least one acid which is introduced into the 
organochlorine compound may vary over a wide range, and generally, the 
amount of acid (on an equivalent basis) is conveniently in the range of 
from about 1.times.10.sup.-5 to about 5 equivalents of acid per equivalent 
of chemically bound (covalent) chlorine in the organo chlorine compound. 
More often the ratio will be from about 1.times.10.sup.-3 to about 2 
equivalents of acid per equivalent of chemically bound chlorine in the 
organochlorine compound. In another embodiment, the amount of acid may 
range from about 0.0001% to about 5% by weight based on the weight of 
organochlorine compound. More often, the acid is present in amounts of 
from about 0.001% to about 2.5% by weight based on the weight of 
organochlorine compound. 
In another embodiment of the present invention, the organochlorine 
compounds are contacted with (a) at least one acid selected from the group 
consisting of Lewis acids, mineral acids other than hydriodic acid and 
hydrobromic acid, and organic acids having a pKa of less than about 2, and 
(b) a source of iodine or bromine for a sufficient amount of time to 
reduce the chlorine content of the organochlorine compound. In one 
preferred embodiment, the organochlorine compound is contacted with at 
least one Lewis acid and a source of iodine or bromine to reduce the 
chlorine content of the organochlorine compound. 
The source of iodine or bromine utilized in the process of the invention 
may be the elemental forms of those materials, preferably iodine. Other 
additional sources of iodine or bromine include the respective hydrogen 
iodide or hydrogen bromide; materials such as I.sub.3.sup.-, I.sup.-, 
I.sub.2 Cl.sup.-, ICl, I.sup.+, or IO.sup.- ; or an organic iodide 
(preferably alkyl) such as t-butyl iodide; or an iodide salt. Sources of 
bromine include bromine, and materials analogous to the iodide sources. It 
is preferred in most situations to avoid the use of a salt as such must 
then be removed or left in the product typically as non-functional 
residue. Where a salt is employed it is preferred that it be the sodium, 
lithium, potassium, calcium or magnesium salt. 
Uniquely, the use of the source of iodine or bromine liberates the chlorine 
but does not appreciably incorporate bromine or iodine into the 
organochlorine compound. It is noted herein that the term organochlorine 
compound refers to the starting compound and in the appropriate context to 
the compound so treated according to the present invention. 
The chlorine content of the starting material may be at any level with the 
desired reduction by the present invention to an appreciably lower level 
in the treated organochlorine compound. The chlorine content of the 
treated organochlorine compound is conveniently reduced to less than 10%, 
preferably less than 5%, more preferably from 0.001% to 1.0%, and 
especially preferably less than 0.5% by weight. For example, where the 
chlorine content of an initial mixture of polyisobutylene and 
polyisobutylene succinic anhydride is from 0.05 to 2% by weight, the 
chlorine content of the resultant mixture (treated according to the 
invention) may be from 0.001 to 0.3 percent by weight. Typically, the 
amount of the iodine or bromine incorporated into the organochlorine 
compound will be less than 40%, more preferably less than 1% to 20% by 
weight of the chlorine removed from the organochlorine product. 
It is noted that varying the source of the iodine or the bromine is not 
particularly important in the present invention since the iodine or 
bromine source may be converted to another form during the dechlorination 
process. Thus the source of iodine or bromine is a material which will 
generate one or more of iodine, bromine, hydrogen iodide, or hydrogen 
bromide. 
The amount of the source of iodine or bromine employed in combination with 
the acid compounds described above is generally determined by one or more 
conditions. Typically, the higher the level of the source of iodine or 
bromine employed the faster and more efficiently the process will proceed 
to reduce the chlorine content of the organochlorine compound. The process 
appears to be one which functions catalytically, that is, the iodine or 
bromine is typically not substantially incorporated into the 
organochlorine compound. Thus the amount of the source of iodine or 
bromine can be reduced to fairly low levels when used in conjunction with 
at least one of the acids described above provided that sufficient time is 
available to treat the organochlorine containing compound. 
The reaction time is generally whatever time is required to achieve the 
desired dechlorination of the organochlorine compound. The reaction may be 
accelerated by the application of mechanical (stirring) and heat energy 
provided that any desired product is not decomposed by the reaction 
conditions. 
When typically dealing with the organochlorine compound, the amount of the 
source of iodine or bromine (on an equivalent basis as iodine or bromine) 
is conveniently from about 1.times.10.sup.-5 to about 10 per equivalent of 
chlorine in the organochlorine compound. More typically the equivalents of 
the source of iodine or bromine present will be from 1.times.10.sup.-3 to 
5 per equivalent of bound chlorine. When an acid and a source of iodine or 
bromine are used in the process of the invention, the relative amounts of 
the two can be varied. Generally the amount of iodine or bromine source is 
greater than the amount of acid used in the process. The order of addition 
of the at least one acid and the iodine or bromine source is not critical 
provided the materials are allowed to mix. 
The process of reducing the chlorine content of the organochlorine compound 
by contacting with at least one acid as described above and a source or 
iodine or bromine is typically conducted between -50.degree. C. and 
300.degree. C. and preferably between 15.degree. C. to 250.degree. C. Most 
preferably the process is conducted at 100.degree. C. to 250.degree. C. 
In another embodiment, the source of iodine or bromine employed in the 
reaction may be the effluent from the same or a different process. The 
effluent may be a gas or a liquid but is preferably a gas. For example, 
when effluent is removed from the reaction mixture of an organochlorine 
compound and a source of iodine or bromine, the effluent may contain at 
least some of the chlorine which has been liberated from the 
organochlorine compound, and unreacted bromine or iodine materials 
initially added to the reaction mixture and bromine or iodine compounds 
formed during the reaction such as hydrogen iodide and hydrogen bromide. 
The effluent containing the liberated chlorine compounds and various 
sources of iodine and bromine can be removed from the reaction mixture by 
blowing with a gas such as nitrogen, by maintaining the reaction mixture 
at an elevated temperature, by distillation, by stripping through the use 
of heat and/or by applying a vacuum, etc. 
The effluent obtained in this manner can be conveniently recycled to the 
same or a different vessel used for treating organochlorine compounds in 
accordance with the process of the present invention. In this embodiment, 
the effluent which is recovered from a first process for recycling to a 
second process may be treated to remove one or more of the different 
chlorine compounds which may be contained in the effluent before the 
effluent is brought into contact with the second organochlorine compound. 
For example, the effluent from the first process may be treated to obtain 
a reduction of its chlorine content prior to contact with the second 
organochlorine compound. Chlorine compounds which may be removed from the 
effluent include hydrogen chloride, low molecular weight alkyl chlorides, 
chlorinated lower olefins, etc. The chlorine content of the effluent may 
be reduced by, for example, treating the effluent with caustic and/or by 
cooling the effluent to a temperature sufficient to liquify one or more of 
the chlorine compounds contained in the effluent and thereafter removing 
the liquified chlorine compounds. 
In another embodiment, the effluent may be treated with an oxidant to 
convert any Hl or HBr in the effluent to elemental iodine or elemental 
bromine before the effluent is used in a second process. For example, Hl 
present in the effluent can be converted to elemental iodine by contacting 
the effluent with a peroxide in the presence of water or air in the 
presence of a transition metal such as copper. 
Accordingly, in one embodiment of the invention, an initial reaction vessel 
containing an organochlorine compound, and optionally, at least one of the 
acids described above is treated with a source of iodine or bromine to 
reduce the chlorine content of the organochlorine compound. During or 
after this treatment, effluent is removed from the reaction mixture by any 
of the methods described above, and the effluent is recycled to the same 
vessel for further treatment of the organochlorine compound or may be 
recycled to a second reaction vessel containing an organochlorine compound 
and at least one acid as described above, to reduce the chlorine content 
of the organochlorine compound contained in the second reaction vessel. In 
this manner, the need for a fresh source of iodine or bromine is minimized 
or eliminated. 
In one embodiment of the present invention, the effluent source of iodine 
or bromine from one reaction mixture is recycled to a second reaction 
vessel rather than being recycled to the same reaction vessel. In this 
embodiment, the source of iodine or bromine introduced into the second 
vessel may be the effluent from another reaction which may involve the 
same or a different organochlorine compound and may or may not include at 
least one acid of the type described above. Thus, the process of the 
invention for reducing the chlorine content of a second organochlorine 
compound may comprise 
(A) contacting the second organochlorine compound with (a) at least one 
acid selected from the group consisting of Lewis acids, mineral acids 
other than hydriodic and hydrobromic acids, and an organic acid having a 
pKa of less than about 2, and (b) a source of iodine or bromine or mixture 
thereof to form one or more different chlorine compounds wherein at least 
a portion of the source of iodine or bromine is obtained from the effluent 
of a first process to reduce the chlorine content of a first 
organochlorine compound wherein the first organochlorine compound is 
contacted with a source of iodine or bromine or a mixture thereof (with or 
without an acid as described above); and 
(B) separating at least one of the different chlorine compounds formed in 
(A) from the second organochlorine compound. Generally, the one or more 
different chlorine compounds formed in the process are more volatile than 
the organochlorine compound which facilitates the separation of the 
different chlorine compounds formed in the process from the organochlorine 
compounds. When the effluent of a first process is utilized as the source 
of iodine or bromine for treating a second organochlorine compound, the 
first organochlorine compound preferably is treated with elemental iodine 
or elemental bromine, or mixtures thereof. The different chlorine 
compounds contained in the effluent of the first process may be removed 
before the effluent is used in the second process. 
As noted above, the organochlorine compound treated in the first process 
may be the same as or different from the organochlorine compound treated 
in the second process with the effluent of the first process. In some 
instances, it may be advantageous to utilize an organochlorine compound in 
the second process which is different from the organochlorine compound 
used in the first process. For example, a polyisobutenylsuccinic anhydride 
compound which contains chlorine may be treated with an initial source of 
iodine or bromine in accordance with the process of the invention, and the 
effluent obtained from this first process may then be utilized to lower 
the chlorine content of, for example, a polyisobutenyl chloride. 
Conducting the reactions on different organochlorine compounds may be 
advantageous depending upon the sensitivity of the organochlorine 
compounds to the type and/or amount of iodine or bromine or other 
by-products in the effluent. For example, it may be more effective to use 
the effluent of a first process for treating a second organochlorine 
compound rather than returning the effluent to the initial organochlorine 
reactor if the second organochlorine compound is more sensitive than the 
first organochlorine compound to the form of iodine or bromine contained 
in the effluent. 
The reaction to reduce the chlorine content may appropriately be run under 
solvent free conditions or under conditions where no added solvent is 
employed. If a solvent is used then a hydrocarbon solvent such as a 
hydrocarbon oil, mineral oil, a hydrogenated polyalphaolefin, 
polyisobutylene, toluene, or xylene are commonly employed. In a preferred 
aspect of the invention where polyisobutenylsuccinic anhydride is treated 
with the source of iodine or bromine there will often be unreacted 
polyisobutylene from the acylation reaction. Thus in a preferred aspect 
the previously mentioned acylation reaction need not have the unreacted 
polyisobutylene removed. It is preferred that the solvent not be one 
containing oxygen moieties such as an aldehyde or ketone, and in 
particular acetone which is volatile, flammable and which must be removed 
from the reaction mixture. The solvent may be used in any useful amount 
such as in a weight ratio to the organochlorine of 0.01 to 250:1, 
conveniently 0.05:1 to 25:1. The term solvent is used freely herein to 
include materials which are sufficient in small amounts to allow a 
reduction in viscosity to facilitate processing. 
The time required to remove the chlorine from the organochlorine compound 
is conveniently 1 hour to 96 hours, often less than 24 hours. It is 
believed that the chlorine is removed from the organochlorine compound by 
the iodine or bromine or certain forms of iodine or bromine such as Hl or 
HBr, and one or more different chlorine compounds or olefins are formed. 
For example, the different compounds may be one or more of the following: 
HCl, organic chloride (e.g., alkyl or alkylene chloride), isobutylene, 
etc. Generally these different compounds are more volatile than the 
organochlorine compound from which they are derived, and these more 
volatile compounds may volatilize and leave the reaction mixture during 
the reaction. 
Removal of the different chlorine compounds can be effected by heating the 
mixture, by applying a vacuum, or by a gas flow through or over the 
mixture. Thus, in one embodiment, the dechlorination process is 
facilitated by blowing an inert gas through the mixture of the 
organochlorine compound and (a) at least one acid selected from the group 
consisting of Lewis acids, mineral acids other than hydriodic acid and 
hydrobromic acid, and organic acids having a pKa of less than about 2, 
and, optionally, (b) a source of iodine or bromine. The gas utilized to 
aid in the process may be any gas which is substantially inert in the 
process such as nitrogen, carbon dioxide, or steam, or the true inert 
gases such as argon or neon. Mixtures of gases such as a mixture of super 
heated steam and nitrogen also are useful. In one embodiment, the gas is 
not hydrogen. 
In one preferred embodiment of the invention, the gas is not bubbled 
through the mixture of organochlorine compound, acid and source of iodine 
or bromine until the source of iodine or bromine has been thoroughly 
blended into the organochlorine compound. If the source of bromine or 
iodine is not thoroughly blended into the organochlorine compound, the gas 
removes the source of bromine or iodine before it can be effective, and 
the overall reduction in chlorine is less than expected. Thus in one 
embodiment, the organochlorine compound is heated in a reactor to an 
elevated temperature such as 100.degree.-150.degree. C. and the acid and 
source of iodine or bromine are added to the reactor and blended into the 
organochlorine compound such as by stirring under closed conditions for 15 
minutes to 2 hours or more. At this time, a gas (preferably nitrogen) is 
bubbled through the mixture in the reaction flask as the temperature is 
raised to about 200.degree.-250.degree. C. Bubbling of the gas (preferably 
vigorous) is continued at this temperature for periods of from 2 or 6 
hours up to 24 hours or more. Volatile chlorine products are formed and 
removed from the reaction vessel with the gas. 
It also has been observed that the gas does not have to be bubbled through 
the mixture of organochlorine compound and iodine or bromine source. The 
chlorine compounds formed during the reaction can be removed by passing 
the gas vigorously over the stirred and heated mixture. In one preferred 
embodiment, the gas can be vigorously bubbled into a slip stream or side 
stream of the reaction mixture which may be forwarded to a holding tank, 
or which may be recirculated to the reaction vessel. Contact of the gas 
with the smaller quantity of reaction mixture in the slip stream or 
recirculation stream results in more rapid and effective removal of the 
chlorine compounds from the reaction mixture. In one variation of the 
invention, the gas is injected into the discharge of the pump on a 
recirculation line for the reaction vessel. The combination of improved 
mixing due to the turbulence in the line and a higher effective 
concentration of gas in the confined space of the line results in 
substantial improvement in the effectiveness of chlorine and chloride 
removal. 
A further feature which may be utilized in the present invention is the 
presence of a proton source. It is believed that proton donors such as 
hydrogen chloride may aid in the dechlorination reaction or at least are 
not harmful to the reaction. In any event the presence of a proton (which 
may be generated in situ) may aid in removing the chlorine from the 
organochlorine compound. One possible mechanism for the removal of 
chlorine is that the chlorine in the organochlorine is converted to the 
corresponding hydrochloride which may be removed conveniently in the 
gaseous state. 
The following examples illustrate the preparation of chlorine-containing 
compounds comprising polyalkenylsuccinic anhydrides which can be treated 
in accordance with the process of the present invention to reduce the 
chlorine content thereof.

EXAMPLE A 
A material useful as a precursor for a dispersant in a motor oil is 
manufactured by forming a mixture of 1,000 parts (0.495 mole) of 
polyisobutene (Mn=2000; Mw=6400) and 106 parts (1.08 moles) of maleic 
anhydride which is heated to 110.degree. C. This mixture is then heated to 
138.degree. C. and further heated to 190.degree. C. over 6 hours during 
which 60 parts (0.85 moles) of gaseous chlorine is added beneath the 
surface. 
At 184.degree.-189.degree. C. an additional 30 parts (0.42 mole) of 
chlorine are added over 4 hours. The reaction mixture is stripped by 
heating at 186.degree.-190.degree. C. with nitrogen blowing for 3 hours. 
The residue is a polyisobutene-substituted succinic acylating agent having 
a total acid number of 93. By analysis, the chlorine content of the 
above-identified product is about 0.72%. 
EXAMPLE B 
A polyisobutenylsuccinic anhydride product is prepared according to the 
Rense patent (U.S. Pat. No. 3,231,587) such that the reaction product 
contains one anhydride group for each equivalent weight of the groups 
derived from a polyisobutenyl precursor of the polyisobutenylsuccinic 
anhydride. By analysis, the chlorine content of the above-identified 
starting product is about 0.310%. 
EXAMPLE C 
The general procedure of Example A is repeated except that the 1000 parts 
of polyisobutene are reacted with 103 parts of maleic anhydride in the 
presence of 90 parts of chlorine. The polyisobutenylsuccinic anhydride 
prepared in this manner contains 0.49% chlorine. 
EXAMPLE D 
A mixture of one mole of polypropylene (Mn=1000) and one mole of maleic 
anhydride is heated to an elevated temperature and a slight excess of 
gaseous chlorine is added beneath the surface over a period of about four 
hours. The reaction mixture is stirred by heating at about 190.degree. C. 
with nitrogen blowing for about 24 hours. The polypropylene-substituted 
succinic anhydride prepared in this manner has a chlorine content of 
0.63%. 
EXAMPLE E 
The general procedure of Example D is repeated except that the 
polypropylene is replaced by an equivalent amount of polyisobutylene 
having an Mn of 1000. The polyisobutenylsuccinic anhydride prepared in 
this manner has a chlorine content of 0.76. 
EXAMPLE F 
The general procedure of Example C is repeated, and the 
polyisobutenylsuccinic anhydride prepared is found to contain 0.3 % 
chlorine. 
EXAMPLE G 
The product of Example C is heated to a temperature of about 
190.degree.-200.degree. C. and maintained at this temperature for 24 hours 
while blowing nitrogen through the mixture. The product is found to 
contain 0.23% chlorine. 
The following examples illustrate the process and products of the present 
invention. 
EXAMPLE 1 
Five-hundred grams of polyisobutenylsuccinic anhydride of Example C are 
heated to 190.degree. C., and 0.1 gram of zinc acetate dihydrate is added. 
The mixture is stirred, and the temperature is raised to 210.degree. C. 
and maintained at this temperature for 1 hour. The mixture then is blown 
with nitrogen (0.5 scfh) for 4 hours whereupon the mixture was cooled and 
recovered as product. The product is found to contain 0.188% chlorine. 
EXAMPLE 2 
Five-hundred grams of the polyisobutenylsuccinic anhydride prepared in 
Example C are heated at 190.degree. C. whereupon 0.24 gram of ferrous 
iodide is added. The mixture is heated to 210.degree. C. and maintained at 
this temperature for 30 minutes whereupon the mixture is blown with 
nitrogen (0.4 scfh) below the surface of the mixture for 4 hours at 
210.degree. C. The mixture then is cooled and the residue is recovered as 
product. The product contained in this manner contains 0.263% chlorine. 
EXAMPLE 3 
The procedure of Example 2 is repeated except that 0.75 gram of ferrous 
iodide is added to the reaction mixture. The product prepared in this 
manner contains 0.186% chlorine and 0.023% iodine. 
EXAMPLE 4 
Five-hundred grams of the polyisobutenylsuccinic anhydride of Example C and 
2 grams of ethyl ethylenetetracarboxylate are mixed and heated to 
210.degree. C. Nitrogen is blown through the mixture. After 12 hours of 
heating at about 210.degree. C., the mixture is cooled, and the residue is 
recovered as product. The product contains 0.199% chlorine. 
EXAMPLE 5 
Five-hundred grams of the polyisobutenylsuccinic anhydride of Example C are 
heated to 190.degree. C., and 0.2 gram of zinc acetate dihydrate is added 
followed by 0.2 gram of iodine. This mixture is heated with stirring to 
210.degree. C. and maintained at this temperature for 30 minutes whereupon 
nitrogen is blown through the mixture for a total of 24 hours at 
210.degree. C. The mixture is cooled and the residue is recovered as 
product. The product contains 0.153% chlorine and 0.034% iodine. 
EXAMPLE 6 
Five-hundred grams of the polyisobutenylsuccinic anhydride of Example C are 
heated to 150.degree. C. with stirring, and 1.12 grams of iodine are added 
to this temperature. After one hour, the temperature is raised to 
190.degree. C., and a flow of nitrogen through the mixture is started. 
Zinc acetate dihydrate (0.28 gram) is added, and this mixture is 
maintained at 190.degree. C. for 30 minutes whereupon the temperature is 
raised to 210.degree. C. and maintained at this temperature for 3 hours. 
Upon cooling, the residue is recovered as the desired product which 
contains 0.118% chlorine and 0.053% iodine. 
EXAMPLE 7 
Five-hundred grams of the polyisobutenylsuccinic anhydride of Example C are 
heated to 150.degree. C. under a stream of nitrogen. The nitrogen stream 
is stopped and 0.2 gram of zinc acetate dihydrate and 0.3 gram of iodine 
are added to the mixture with stirring. The mixture then is heated to 
210.degree. C. and maintained at this temperature for 4 hours whereupon 
nitrogen is blown through the mixture with stirring for 4 hours at 
210.degree. C. The mixture is cooled and the residue is recovered as the 
product which contains 0.132% chlorine and 0.037% iodine. 
EXAMPLE 8 
Five-hundred grams of the polyisobutenylsuccinic anhydride of Example C are 
heated to 190.degree. C. under an atmosphere of nitrogen. At this 
temperature, the nitrogen flow is stopped and 0.1 gram of zinc acetate 
dihydrate and 1 gram of iodine are added. The mixture is stirred and the 
temperature of the mixture is raised to 210.degree. C. After 30 minutes at 
this temperature, a subsurface stream of nitrogen is begun, and the 
mixture is maintained at this temperature for 4 hours. The mixture then is 
cooled and the residue is recovered as product which contains 0.092% 
chlorine and 0.057% iodine. 
EXAMPLE 9 
Five-hundred grams of the polyisobutenylsuccinic anhydride of Example C is 
heated to 190.degree. C. with nitrogen blowing at 0.3 scfh. The nitrogen 
blowing is stopped, and 0.1 gram of zinc acetate dihydrate is added. The 
mixture is stirred for 4 minutes whereupon 2 grams of iodine are added. 
The mixture is heated to 210.degree. C. and maintained at this temperature 
for 30 minutes without nitrogen blowing. The nitrogen blowing is then 
begun at 0.5 scfh and maintained for 4 hours at 210.degree. C. The mixture 
is then cooled and the residue is the product containing 0.097% chlorine 
and 0.073% iodine. 
EXAMPLE 10 
The general procedure of Example 9 is repeated except that only 0.5 gram of 
iodine is added to the mixture. The product prepared in this manner 
contains 0.130% chlorine. 
EXAMPLE 11 
Five-hundred grams of the polyisobutenylsuccinic anhydride of Example C are 
heated with stirring to 150.degree. C., and 0.2 gram of zinc acetate 
dihydrate is added. The mixture is then heated to 190.degree. C. whereupon 
0.5 gram of iodine is added. The mixture is stirred at 190.degree. C. for 
1 hour, and nitrogen is blown through the mixture at 1 scfh over a period 
of 24 hours while maintaining the temperature at about 190.degree. C. The 
residue is recovered as the product, and the product contains 0.104% 
chlorine and 0.081% iodine. 
EXAMPLE 12 
Five-hundred grams of the polyisobutenylsuccinic anhydride of Example C are 
heated to 150.degree. C. while blowing with nitrogen at 0.2 scfh whereupon 
0.1 gram of ferric chloride is added and the nitrogen flow is stopped. 
Iodine (0.6 gram) is added, and the mixture is heated to 210.degree. C. 
and maintained at this temperature for 1 hour. At this time, the flow of 
nitrogen is resumed at 0.2 scfh, and the mixture is maintained at 
210.degree. C. for 3 hours. Upon cooling, the residue is recovered as the 
product which contains 0.133% chlorine and 0.023% iodine. 
EXAMPLE 13 
Five-hundred grams of the polyisobutenylsuccinic anhydride of Example C are 
heated with stirring to 150.degree. C. while blowing with nitrogen at 0.5 
scfh. At 150.degree. C., 10 drops of 93% sulfuric acid are added as the 
mixture is heated with nitrogen blowing to 190.degree. C. At this 
temperature, 2 grams of iodine are added, and the nitrogen blowing is 
stopped. The mixture is stirred for 5 minutes, and 0.5 gram of ferric 
chloride is added. The mixture is heated to 210.degree. C. with stirring 
for 30 minutes without nitrogen. At this time, nitrogen blowing is resumed 
at 0.5 scfh, and the temperature is maintained at 210.degree. C. for 4 
hours. The mixture is cooled and the residue is the product containing 
0.084% of chlorine. 
EXAMPLE 14 
Five-hundred grams of the polyisobutenylsuccinic anhydride of Example C are 
heated to a temperature of 150.degree. C. while blowing with nitrogen at 
0.5 scfh. At this temperature, 10 drops of 93% sulfuric acid are added and 
the mixture is heated to 190.degree. C. with nitrogen blowing. Iodine (2 
grams) is then added to the mixture followed by 0.1 gram of ferric 
chloride. The nitrogen blowing is stopped and the mixture is heated to 
210.degree. C. and maintained at this temperature for 30 minutes without 
nitrogen blowing. The nitrogen mixture then is blown with nitrogen at 0.5 
scfh for 4 hours at 210.degree. C., and the cooled residue is the desired 
product containing 0.085 % of chlorine. 
EXAMPLE 15 
The general procedure of Example 14 is repeated except that the ferric 
chloride is replaced by 0.1 gram of zinc acetate dihydrate. The product 
obtained in this manner contains 0.071% chlorine. 
EXAMPLE 16 
Five-hundred grams of the polyisobutenylsuccinic anhydride of Example C are 
heated to 150.degree. C. while blowing with nitrogen at 0.2 scfh, and 1.12 
grams of iodine are added. The nitrogen flow is stopped and the mixture is 
stirred for 1 hour at 150.degree. C. and then heated to 190.degree. C. At 
190.degree. C., the mixture is blown with nitrogen and 0.11 gram of 
magnesium is added. After maintaining the mixture at 190.degree. C. for 30 
minutes, the mixture is heated to 210.degree. C. and maintained at this 
temperature for 3 hours. The mixture is cooled, and the residue is the 
product which contains 0.179% chlorine and 0.034% iodine. 
EXAMPLE 17 
Five-hundred grams of the polyisobutenylsuccinic anhydride of Example C are 
heated with stirring to 150.degree. C. while blowing with nitrogen at 0.6 
scfh. Magnesium sulfate (0.5 gram) is added, and the nitrogen blowing is 
stopped. The mixture is heated to 190.degree. C. whereupon 1 gram of 
iodine is added. After heating the mixture to 210.degree. C. and 
maintaining the mixture at this temperature for 1 hour, the mixture is 
again blown with nitrogen at 0.5 scfh and maintained at 210.degree. C. for 
4 hours. The mixture is then cooled and the residue is recovered as 
product which contains 0.155 % chlorine. 
EXAMPLE 18 
Five-hundred grams of the polyisobutenylsuccinic anhydride of Example C are 
heated to 150.degree. C. while blowing with nitrogen at 0.6 scfh. The 
nitrogen blowing is stopped, and 0.25 gram of zinc oxide is added with 
stirring. The mixture is then heated to 190.degree. C. whereupon 0.5 gram 
of iodine is added. The mixture is heated to 210.degree. C. and maintained 
at this temperature for 1 hour. The mixture then is blown with nitrogen at 
0.6 scfh and maintained at 210.degree. C. for 24 hours. After cooling, the 
residue is collected as product which contains 0.072% chlorine and 0.090% 
iodine. 
EXAMPLE 19 
Five-hundred grams of the polyisobutenylsuccinic anhydride of Example C are 
heated to 150.degree. C. while blowing with nitrogen at 0.6 scfh. At 
150.degree. C., the nitrogen is stopped, and 0.25 gram of calcium sulfate 
is added. This mixture is stirred for 10 minutes and heated to 190.degree. 
C. whereupon 0.5 gram of iodine is added. The mixture is then heated to 
210.degree. C. and maintained at this temperature for 1 hour whereupon the 
mixture was then blown with nitrogen for 24 hours while maintaining the 
temperature of the mixture at 210.degree. C. The mixture is cooled, and 
the residue is the desired product containing 0.083% chlorine and 0.031% 
iodine. 
EXAMPLE 20 
Five-hundred grams of the polyisobutenylsuccinic anhydride of Example C are 
heated to 190.degree. C. and 0.1 gram of zinc oxide and 0.25 gram of 
iodine are added. The mixture is then heated to 210.degree. C., and after 
1 hour at this temperature, nitrogen is blown through the mixture at 0.4 
scfh for 4 hours. The mixture is cooled and the residue is the product 
containing 0.158% chlorine and 0.035% iodine. 
EXAMPLE 21 
Five-hundred grams of the polyisobutenylsuccinic anhydride of Example C are 
heated to 190.degree. C. and 0.29 gram of zinc oleate and 1 gram of iodine 
are added. This mixture is heated with stirring to 210.degree. C. and 
maintained at this temperature for 30 minutes. The mixture is blown with 
nitrogen for 4 hours whereupon the mixture is cooled and the residue is 
recovered as the product. The product contains 0.093% chlorine and 0.064% 
iodine. 
EXAMPLE 22 
The procedure of Example 22 is repeated except that only 0.14 gram of zinc 
oleate is added to the mixture. The product obtained in this manner is 
found to contain 0.080% chlorine and 0.049% iodine. 
EXAMPLE 23 
Five-hundred grams of the polyisobutenylsuccinic anhydride of Example F are 
heated to 190.degree. C. whereupon 0.2 gram of zinc acetate is added 
followed by 0.1 gram of ferric chloride and 0.2 gram of iodine. This 
mixture is blown with nitrogen at 0.5 scfh as the mixture is heated to 
200.degree. C. The mixture is maintained at this temperature with nitrogen 
blowing for 12 hours. The mixture is cooled, and the residue is recovered 
as product which contains 0.091% chlorine and 0.024% iodine. 
EXAMPLE 24 
Five-hundred grams of the polyisobutenylsuccinic anhydride of Example F are 
heated with stirring to 190.degree. C. while blowing with nitrogen at 0.5 
scfh. The nitrogen blowing is stopped, and zinc acetate (0.2 gram), ferric 
chloride (0.1 gram), and iodine (0.2 gram) are added to the mixture with 
stirring at 190.degree. C. The mixture is maintained at this temperature 
for 30 minutes whereupon the mixture is heated to 210.degree. C. At this 
temperature, the mixture is blown with nitrogen at 0.6 scfh for 4 hours. 
The mixture is cooled, and the residue is recovered as product which 
contains 0.077% chlorine and 0.034% iodine. 
EXAMPLE 25 
Five-hundred grams of the polyisobutenylsuccinic anhydride of Example G are 
heated to 190.degree. C. while blowing with nitrogen at 0.5 scfh. The 
nitrogen blowing is stopped, and 0.2 gram of zinc acetate dihydrate and 
0.2 gram of iodine are added. This mixture is heated with stirring to 
210.degree. C. and maintained at this temperature for 30 minutes. The 
nitrogen blowing is resumed, and the mixture is maintained at 210.degree. 
C. for 4 hours. The mixture is cooled and the residue is recovered as 
product which contains 0.144% chlorine and 0.028% iodine. 
EXAMPLE 26 
Five-hundred grams of the polyisobutenylsuccinic anhydride of Example C are 
heated to 210.degree. C., and the effluent (volatiles) from the procedure 
of Example 25 are allowed to pass through the mixture for 6 hours at this 
temperature. The reaction mixture is cooled and the residue is recovered 
as product. 
EXAMPLE 27 
The procedure of Example 13 is repeated except the polyisobutenylsuccinic 
anhydride of Example C is replaced by 500 grams of the 
polypropylene-substituted succinic anhydride of Example D. 
EXAMPLE 28 
Five-hundred grams of polyisobutenylsuccinic anhydride of Example C are 
heated to 190.degree. C., and 0.25 gram of zinc iodide is added. This 
mixture is heated to 210.degree. C. with stirring and maintained at this 
temperature for 30 minutes whereupon a stream of nitrogen is bubbled 
through the mixture at 0.4 scfh. Nitrogen blowing is continued for 4 hours 
whereupon the mixture is cooled and recovered as product. The product 
contains 0.198% chlorine and 0.07% iodine. 
EXAMPLE 29 
Five-hundred grams of the polyisobutenylsuccinic anhydride of Example C are 
heated to 150.degree. C. with nitrogen blowing at 0.6 scfh. The nitrogen 
blowing is stopped, and 0.2 gram of zinc acetate is added. The mixture is 
heated to 190.degree. C. whereupon 0.5 gram of iodine is added, and the 
mixture is maintained at 210.degree. C. for 1 hour. At this time, nitrogen 
is blown through the mixture at 0.5 scfh and then at 1 scfh. The mixture 
is maintained at 210.degree. C. with nitrogen blowing at 1 scfh for 24 
hours while removing volatile materials. The residue is recovered as the 
product which is found to contain 0.072% chlorine and 0.070% iodine. 
EXAMPLE 30 
Five-hundred grams of the polyisobutenylsuccinic anhydride of Example C are 
stirred and heated to 150.degree. C. with nitrogen blowing at 0.5 scfh. At 
this temperature, 5 drops of 93% sulfuric acid are added and nitrogen 
blowing is stopped. The mixture is heated to 210.degree. C. and maintained 
at this temperature without nitrogen blowing for 30 minutes. The mixture 
then is blown with nitrogen at 0.5 scfh for 4 hours at 210.degree. C. 
After cooling at room temperature, the residue is recovered as the product 
which contains 0.224% chlorine. 
EXAMPLE 31 
Five-hundred grams of the polyisobutenylsuccinic anhydride of Example C are 
heated with stirring to a temperature of 150.degree. C. with nitrogen 
blowing at 0.5 scfh. At this temperature, 5 drops of 93% sulfuric acid are 
added and the nitrogen blowing is stopped. The mixture is heated to 
190.degree. C., and 0.25 gram of iodine is added. The mixture is heated to 
210.degree. C. and maintained at this temperature without nitrogen blowing 
for one-half hour. The mixture then is blown with nitrogen at 0.5 scfh for 
4 hours at 210.degree. C. The residue is cooled and recovered as the 
product which is found to contain 0.164% chlorine and 0.01 6% iodine. 
EXAMPLE 32 
Five-hundred grams of the polyisobutenylsuccinic anhydride of Example C are 
stirred and heated to 160.degree. C. with nitrogen blowing at 0.5 scfh. At 
this temperature, the nitrogen blowing is stopped, and 5 drops of 93% 
sulfuric acid are added. This mixture is heated without nitrogen blowing 
to 190.degree. C., and at this temperature, 0.25 gram of iodine is added. 
The mixture is heated to 210.degree. C. without nitrogen and maintained at 
this temperature for 1 hour. Nitrogen is then blown through the mixture at 
1 scfh for 4 hours at 210.degree. C. The residue is cooled and recovered 
as the product which is found to contain 0. 150% chlorine and 0.018% 
iodine. 
EXAMPLE 33 
Five-hundred grams of the polyisobutenylsuccinic anhydride of Example C are 
heated to 190.degree. C., and zinc iodide is added. The mixture is heated 
to 210.degree. C. and maintained at this temperature for 30 minutes 
whereupon nitrogen is blown through the mixture at 0.4 scfh for 4 hours. 
The mixture is cooled, and the residue is recovered as the product which 
is found to contain 0.121% chlorine and 0.096% iodine. 
EXAMPLES 34-38 
In these examples, 500 grams of the polyisobutenylsuccinic anhydride of 
Example C are heated to 190.degree. C. whereupon 0.2 gram of iodine and 
0.2 gram of zinc acetate are added. This mixture is then heated to 
210.degree. C. over a period of 1 hour whereupon nitrogen is blown through 
the mixture at 0.3 scfh for a total of 16 hours. Samples are removed from 
the reaction mixture for analysis after 2, 4, 6, 8 and 17 hours of total 
heating. The results of the chlorine and nitrogen analysis on the samples 
recovered in Examples 34-38 are shown in the following Table I. 
For comparison purposes, the procedure of Examples 34-38 is repeated except 
that the zinc acetate is omitted. These examples are identified as 34C, 
35C, 36C, 37C and 38C. Thus, the mixture which is heated contains 500 
grams of the polyisobutenyl succinic anhydride of Example C and 2 grams of 
iodine. The chlorine and iodine analysis for the samples of the reaction 
mixture recovered at 2, 4, 6, 8 and 17 hours of total heating (190.degree. 
C. and 210.degree. C.) also are summarized in the following Table I. 
TABLE I 
______________________________________ 
Total Heating Chlorine Iodine 
Example (hours) % w % w 
______________________________________ 
34 2 0.102 0113 
34C 2 0.281 0077 
35 4 0.078 0083 
35C 4 0.202 0042 
36 6 0.069 0076 
36C 6 0.167 0040 
37 8 0.068 0079 
37C 8 0.133 0034 
38 17 0.061 0061 
38C 17 0.096 0029 
______________________________________ 
As can be seen from the results summarized in the above Table I, although 
iodine alone is effective in reducing the chlorine content, and the 
chlorine content decreases as the time of heating is extended, the 
chlorine content of the reaction mixtures are further reduced when zinc 
acetate is used in combination with the iodine. 
The present invention contemplates the use of the products herein, 
particularly the polyalkenylsuccinic anhydrides containing reduced amounts 
of chlorine, as intermediates for the manufacture of dispersants for 
lubricants, and in particular lubricants for four cycle engine crankcases. 
The products of the invention are also useful as intermediates for, and 
components, of two cycle oils and fuels including gasoline. The products 
obtained herein are often used in concentrate or additive packages. 
Procedures for preparing esters, amides, imides, amine salts and metal 
salts from carboxylic acylating agents are well known to those skilled in 
the art and are described in many patents. For example, reactions with 
hydroxy compounds to form esters are described in U.S. Pat. Nos. 
3,331,776; 3,381,022; 3,522, 179; and 3,542,680; reactions with amines to 
form amides, imides and amine salts are described in U.S. Pat. Nos. 
3,172,892; 3,219,666; and 3,272,746; and reactions with reactive metals to 
form metal salts are described in U.S. Pat. Nos. 3,271,310; 3,306,908; and 
Re 26,433. All of these patents are expressly incorporated herein by 
reference. 
In particular, such dispersants may be made by reaction with polyamines 
and/or polyols as described in U.S. Pat. No. 4,234,435 issued Nov. 18, 
1980 to Meinhardt and Davis or U.S. Pat. No. 3,215,707 issued Nov. 2, 1965 
to Rense both of which are incorporated herein by reference. 
While a polyamine or a mixed polyamine ester product may be treated with 
the source of iodine or bromine to remove the halogen, such is not always 
desirable. That is, the process is most conveniently conducted on the 
acylating agent precursor for various reasons including cost and 
throughput considerations. 
The following examples illustrate the preparation of products useful as 
dispersants and lubricating oil compositions. 
EXAMPLE I 
The product of Example 1 is processed according to Example 10 of U.S. Pat. 
No. 4,234,435 (Meinhardt) to produce an aminated dispersant useful in a 
lubricating oil. 
EXAMPLE II 
The product of Example 5 is processed according to Example 12 of U.S. Pat. 
No. 4,234,435 to produce an aminated dispersant useful in a lubricating 
oil. 
EXAMPLE III 
The polyisobutenylsuccinic anhydride of Example 15 is processed according 
to the procedure of Example 13 of U.S. Pat. No. 4,234,435 to produce a 
product containing ester and amine functionalities which is useful as a 
dispersant in the lubricating oil. 
Esters of the polyalkenylsuccinic anhydrides can be prepared utilizing the 
procedures of U.S. Pat. No. 4,234,435 by reacting the anhydrides with 
polyols such as pentaerythritol. The products of Examples I to III may be 
further treated according to industry practices to obtain further useful 
products. For example, the products of Examples I to III can be reacted 
with boric acid to prepare boronated dispersants. 
The polyalkenyl-substituted succinic acids containing a reduced amount of 
chlorine can be used, as noted above, to prepare dispersants useful in 
lubricants, two-cycle oils, emulsions and fuels including gasoline. More 
particularly, the dispersants which may be prepared from the 
polyalkenylsuccinic anhydrides or acids prepared in accordance with the 
process of this invention and containing a reduced amount of chlorine may 
be employed in a variety of lubricants based on diverse oils of 
lubricating viscosity, including natural and synthetic lubricating oils 
and mixtures thereof. These lubricants include crankcase lubricating oils 
for spark-ignited and compression-ignited internal combustion engines, 
including automobile and truck engines, two-cycle engines, aviation piston 
engines, marine and railroad diesel engines, etc. They can also be used in 
gas engines, stationary power engines and turbines and the like. Automatic 
or manual transmission fluids, transaxle lubricants, gear lubricants, 
including open and enclosed gear lubricants, tractor lubricants, 
metal-working lubricants, hydraulic fluids and other lubricating oil and 
grease compositions can also benefit from the incorporation therein of the 
dispersants discussed above. The dispersants may also be used in wire 
rope, walking cam, way, rock drill, chain and conveyor belt, worm gear, 
bearing, and rail and flange lubricants. 
Products such as those described above in Examples I to III may be used in 
lubricants or in concentrates, by themselves or in combination with any 
other known additives which include, but are not limited to other 
dispersants, detergents, antioxidants, anti-wear agents, extreme pressure 
agents, emulsifiers, demulsifiers, foam inhibitors, friction modifiers, 
anti-rust agents, corrosion inhibitors, viscosity improvers, pour point 
depressants, dyes, and solvents to improve handleability which may include 
alkyl and/or aryl hydrocarbons. These additives may be present in various 
amounts depending on the needs of the final product. 
Other dispersants include, but are not limited to, Mannich dispersants and 
mixtures thereof as well as materials functioning both as dispersants and 
viscosity improvers. Mannich dispersants are prepared by reacting a 
hydroxy aromatic compound with an amine and aldehyde. The dispersants 
described above may be post-treated with reagents such as urea, thiourea, 
carbon disulfide, aldehydes, ketones, carboxylic acids, 
hydrocarbon-substituted succinic anhydride, nitriles, epoxides, boron 
compounds, phosphorus compounds and the like. 
Detergents include, but are not limited to, Newtonian or non-Newtonian, 
neutral or basic salts of alkaline earth or transition metals with one or 
more hydrocarbyl-substituted sulfonic, carboxylic, phosphoric, 
thiophosphoric, dithiophosphoric, phosphinic acid, or thiophosphinic 
acids, sulfur coupled phenol or hydrocarbon-substituted phenols. Basic 
salts are salts that contain a stoichiometric excess of metal present per 
acid function. 
Auxiliary extreme pressure agents and corrosion- and oxidation-inhibiting 
agents which may be included in the lubricants of the invention are 
exemplified by chlorinated aliphatic hydrocarbons such as chlorinated 
olefins or wax; organic sulfides and polysulfides such as benzyl 
disulfide, bis(chlorobenzyl)disulfide, dibutyltetrasulfide, sulfurized 
methyl ester of oleic acid, sulfurized alkylphenol, sulfurized dipentene, 
and sulfurized terpene; phosphosulfurized hydrocarbons such as the 
reaction product of a phosphorus sulfide with turpentine or methyl oleate, 
phosphorus esters including principally dihydrocarbyl and trihydrocarbyl 
phosphites such as dibutyl phosphite, diheptyl phosphite, dicyclohexyl 
phosphite, pentyl phenyl phosphite, dipentyl phenyl phosphite, tri-decyl 
phosphite, distearyl phosphite, dimethyl naphthyl phosphite, oleyl 
4-pentylphenyl phosphite, polypropylene (molecular weight 500)-substituted 
phenyl phosphite, diisobutyl-substituted phenyl phosphite; dithiocarbamate 
containing amides prepared from dithiocarbamic acid and an acrylamide 
(e.g., the reaction product of dibutylamine, carbon disulfide and 
acrylamide); alkylene-coupled dithiocarbamates (e.g., methylene or 
phenylene bis(dibutyldithiocarbamate)); and sulfur-coupled 
dithiocarbamates (e.g., bis(s-alkyldithiocarbamoyl)disulfides); metal 
thiocarbamates, such as zinc dioctyldithiocarbamate, and barium 
heptylphenyl dithiocarbamate; boron-containing compounds including borate 
esters; molybdenum compounds; Group II metal phosphorodithioates such as 
zinc dicyclohexylphosphorodithioate, zinc dioctylphosphorodithioate, 
barium di(heptylphenyl)-phosphorodithioate, cadmium 
dinonylphosphorodithioate, and the zinc salt of a phosphorodithioic acid 
produced by the reaction of phosphorus pentasulfide with an equimolar 
mixture of isopropyl alcohol and n-hexyl alcohol. 
Viscosity improvers include, but are not limited to, polyisobutenes, 
polymethacrylate acid esters, polyacrylate acid esters, hydrogenated diene 
polymers, polyalkyl styrenes, hydrogenated alkenyl aryl conjugated diene 
copolymers, polyolefins and multifunctional viscosity improvers. 
Pour point depressants are a particularly useful type of additive often 
included in the lubricating oils described herein. See, for example, page 
8 of "Lubricant Additives" by C. V. Smalheer and R. Kennedy Smith 
(Lesius-Hiles Company Publishers, Cleveland, Ohio, 1967). 
Anti-foam agents used to reduce or prevent the formation of stable foam 
include silicones or organic polymers. Examples of these and additional 
anti-foam compositions are described in "Foam Control Agents," by Henry T. 
Kerner (Noyes Data Corporation, 1976), pages 125-162. 
These and other additives are described in greater detail in U.S. Pat. No. 
4,582,618 (Col. 14, line 52 through Col. 17, line 16, inclusive), herein 
incorporated by reference for its disclosure of other additives that may 
be used in combination with the present invention. 
The concentrate may contain 0.01% to 90% by weight of the dispersants of 
the invention. The dispersants may be present in a final product, blend or 
concentrate in a minor amount, i.e., up to 50% by weight or in any amount 
effective to act as a dispersants, but is preferably present in oil of 
lubricating viscosity, hydraulic oils, fuel oils, gear oils or automatic 
transmission fluids in an amount of from about 0.1% to about 10%. 
The lubricating compositions and methods of this invention employ an oil of 
lubricating viscosity, including natural or synthetic lubricating oils and 
mixtures thereof. Natural oils include animal oils, vegetable oils, 
mineral lubricating oils, solvent or acid treated mineral oils, and oils 
derived from coal or shale. Synthetic lubricating oils include hydrocarbon 
oils, halo-substituted hydrocarbon oils, alkylene oxide polymers, esters 
of carboxylic acids and polyols, esters of polycarboxylic acids and 
alcohols, esters of phosphorus-containing acids, polymeric 
tetrahydrofurans, silicon-based oils and mixtures thereof. 
Specific examples of the oils of lubricating viscosity are described in 
U.S. Pat. No. 4,326,972 and European Patent Publication 107,282, both 
herein incorporated by reference for their disclosures relating to 
lubricating oils. A basic, brief description of lubricant base oils 
appears in an article by D. V. Brock, "Lubricant Base Oils," Lubricant 
Engineering, Vol. 43, pages 184-185, March, 1987. This article is herein 
incorporated by reference for its disclosures relating to lubricating 
oils. A description of oils of lubricating viscosity occurs in U.S. Pat. 
No. 4,582,618 (Col. 2, line 37 through Col. 3, line 63, inclusive), herein 
incorporated by reference for its disclosure to oils of lubricating 
viscosity. 
While the invention has been explained in relation to its preferred 
embodiments, it is to be understood that various modifications thereof 
will become apparent to those skilled in the art upon reading the 
specification. Therefore, it is to be understood that the invention 
disclosed herein is intended to cover such modifications as fall within 
the scope of the appended claims.