US3172892A - Reaction product of high molecularweight succinic acids and succinicanhydrides with an ethylene poly-amine - Google Patents

Description

REACTION PRODUCT OF HIGH MOLECULAR WEIGHT SUCClNllC ACIDS AND SU'CCINIC ANHYDRIDES WITH AN ETHYLENE POLY- AMINE William M. 'Le Suer, Cleveland, and George R. Norman,

Lyndhurst, Ohio, assignors to The Luhrizol Corporation, Wickliife, Ohio, a corporation of Ohio No Drawing. Filed Mar. 30, 1959, Ser. No. 802,667

6 Claims. (Cl. 260-3265) This invention relates to a process for the preparation of an oil-soluble product which is useful as a dispersing agent in lubricating compositions. The product is particularly useful in lubricating compositions intended for use in the crankcase of internal combustion engines.

One of the principal problems associated with present day crankcase lubricants is that posed by the inevitable presence in the lubricant of foreign particles such as dirt, soot, water and decomposition products resulting from breakdown of the oil. Even if there was none of this latter contaminant present the very nature of the design of the modern internal combustion engine is such that a significant amount of foreign matter will accumulate in the crankcase. Perhaps the most important of these contaminants is water because it seems to be responsible for the deposition of a mayonnaise-likesludge. It appears that if there were no water present the solid components of the mayonnaise-like sludge would circulate with the oil and be removed by the oil filter; It will be readily appreciated that the deposition of the sludge presents a serious problem with respect to the efiicient operation of the engine and that it is desirable to prevent such deposition of sludge-like material.

The presence of water and the precursors of sludge in a lubricating oil is dependent largely upon the operating temperature of the oil. If the oil is operated at a high temperature the water of course will be eliminated by evaporation about as fast as it accumulates. In the absence of water, as stated above, the other foreign particles will be removed by the filter. At low oil temperatures, on the other hand, water will accumulate and so consequently will sludge. It is apparent that the environment in which a crankcase lubricant is maintained will determine to a large extent the ultimate performance of that lubricant.

High operating temperatures are characteristic of a lubricant in an engine that is run at relative constant high speed. Thus in an engine that is run at 60 mph. for a long period of time it is very unlikely there would be any accumulation of water and it is similarly unlikely that there will be any formation and deposition of sludge. But in ordinary stop-and-go driving, as is the case with taxicabs, delivery trucks, police cruisers, etc., the crankcase lubricant will be alternately hot and cold, an ideal environment for the accumulation of water. In such cases the formation of sludge is a serious problem. This problem has been with the automotive industry for many years and its solution has been approached by the use of known detergents such as alkaline earth metal phenates and sulfonates, but without notable success. Although such known detergents are very effective in solving the detergency problems associated with motor oils at high temperatures, they have not been particularly effective in solving the problems associated with low temperature operation, or to put it better, those problems which are associated with crankcase lubricants in engines which are operated at alternating high and low temperatures.

It is accordingly a principal object of this invention to provide a novel process for the preparation of products which are effective as dispersants in lubricant compositions.

te States atent 3,172,392 Patented Mar. 9, i965 proved lubricant compositions.

These and other objects of the invention are achieved.

by the process of preparing an oil-soluble acylated amine suitable for use as a dispersant in lubricant compositions which comprises mixing a substituted succinic compound selected from the class consisting of substituted succinic acids having the structural formula and substituted succinic anhydrides having the structural formula R-CHCO in which structural formulas R is a large, substantially aliphatic hydrocarbon radical having at least about 50 carbon atoms, with at least about one-half an equivalent amount of an ethylene amine, and heating the resulting mixture to effect acylati on and remove the water formed thereby.

It will be seen that the reaction of this process, involving an amidation of a dicarboxylic acid (or anhydride thereof) with a polyamine, can result in a simple acyclic diamide, a cyclic diamide, a polymeric amide or a combination of any of these types of products. It will be noted also that the amide groups may react further to form imide groups and it is believed that a substantial amount of imide formation takes .place in the process. Furthermore there is reason to believe that in certain instances there is present in the product an appreciable proportion of amine carboxylate salt.

The size of the substituent of the succinic acid or anhydride is of major importance in the process because it allows the preparation of a product which satisfies the objects of the invention, i.e., one which is effective as a dispersant in low-temperature engine lubricants. It is critically important that this substituent be large, that it have at least about 50 carbon atoms in its structure. These substituent groups are substantially aliphatic hydrocarbon radicals, including both alkyl and alkenyl radicals. They are commonly derived from polyolefins such as polyethylene, polypropylene, polybutylcne, etc., although they may be derived from any substantially aliphatic hydrocarbon.

The substituted succinic acids and anhydrides which are contemplated as a reactant in the process are readily available from the reaction of maleic anhydride with a. high molecular weight olefin or a chlorinated high molecular weight olefin. The product from such a reaction is the corresponding alkenyl succinic anhydride The reaction involves merely heating the two reactants at a temperature of about ISO-200 C. The reactions in each case are illustrated by the following equations.

It will be appreciated that the reactions may not go precisely as indicated in the above equations, especially with respect to the particular carbon'atom of the olefin or chloride reactant which ultimately becomes attached to the maleic acid or anhydride reactant, but other than this the equations are believed to be illustrative. Furthermore although the product of this reaction has been indicated as being an alkenyl succinic anhydride it is apparent that similar products can be prepared by this process in which the substituent is something other than an alkenyl group. For the purposes of this invention this substituent should, however, be a substantially aliphatic group and in most cases of course it will be an alkyl or alkenyl group. In some cases, however, it may well be desirable to employ a substituted succinic anhydride in which the substituent is derivedfrom a copolymer of styrene and isobutylene, or of a substituted styrene and some other aliphatic olefin. In these latter cases the copolymer will be substantially aliphatic, that is, the composition of the copolymer will be predominantly aliphatic, i.e., more than about 90% of the monomeric units will be those of the aliphatic monomer. I

As mentioned earlier the size of this substituent group appears to determine the effectiveness of the product of the process of the invention as a dispersant in motor oils. Substituted succinic anhydrides and their derivatives have been known for some time and it has likewise been known that these compounds are useful in lubricants, but their utility heretofore has been predicated upon their rustpreventing properties, corrosion-inhibiting properties, viscosity-temperature characteristics, etc. The usefulness of compositions of this type as dispersants has never been realized and an important aspect of this invention resides in the discovery that by increasing the size of this particular substituent an entirely new property, i.e., dispersancy, can be incorporated into the composition.

The most commonly used sources of these substantially aliphatic hydrocarbon substituents are the polyolefins. These are illustrated by polyethylene, polypropylene, polyisobutylene, etc. A particularly preferred polyolefin for this use is polyisobutylene. Thus the condensation of a polyisobutylene having a molecular weight of 750 with maleic anhydride yields an alkenyl succinic anhydride which upon further reaction with an ethylene amine produces an especially effective lubricating oil dispersant. Polyisobutylenes of this particular molecular weight are quite economically available and the effectiveness of products prepared from this material makes this starting material particularly desirable for use in a process of this invention.

The substituted succinic anhydride ordinarily is reacted directly with the ethylene amine although in some circumstances it may be desirable first to convert the anhydride to the acid before reaction with diamine. In other circumstances it may be desirable to prepare the substituted succinic acid by some other means and to use an acid prepared by such other means in the process. In any event either the acid or the anhydride may be used in the process of this invention.

The term ethylene amine is used in a generic sense to denote a class of polyamines conforming for the most part of the structure It in which 2: is an integer and -R is a low molecular weight alkyl radical or hydrogen. Thus it includes for example ethylene diamine, diethylene triamine, triethylene tetramine, tretaethylene pentamine, pentaethylene hexamine, etc. These compounds are discussed in some detail under the heading Ethylene Amines in Encyclopedia of Chemical Technology, Kirk and Othmer, vol. 5, pages 898-905, Interscience Publishers, New York (1950). Such compounds are prepared most conveniently by the reaction of ethylene dichloride with ammonia. This process results in the production of' somewhat complex mixtures of ethylene amines. including cyclic condensation products such as piperazines and these mixtures find use in the process of this invention. On the other hand quite satisfactory products may be obtained also by the use of pure ethylene amines. An especially useful ethylene amine, for reasons of economy as well as ellectivcness as a dispersant, is a mixture of ethylene amines prepared by the reaction ethylene chloride and ammonia, having a composition which corresponds to that of tetracthylcne pentamine. This is available in the trade under the trade name Polyamine H.

It has been noted that at least one half of a chemical equivalent amount of the ethylene amine per equivalent of substituted succinic anhydride must be used in the process to produce a satisfactory product with respect to dispersant properties and generally it is preferred to use these reactants in equivalent amounts. Amounts up to 2.0 chemical equivalents (per equivalent of substituted succinic anhydride) have been used with success, although there appears to be no advantage attendant upon the use of more than this amount. The chemical equivalency of the ethylene amine reactant is upon the nitrogen content, i.e., one having four nitrogens per molecule has four equivalents per mole.

The reaction of the process involves a splitting out of water and the reaction conditions are such that this water is removed as it is formed. Presumably the first principal reaction that occurs, following salt formation, is the formation of a half amide R-CHCO R--(.IICOOII 0 InNR crncoNiIR CIl CO followed then by salt formation R-CHCOOH n-orrcoorntirn +1-nNR HgCONHR Il CONHR and involving finally dehydration of this salt to form the product fore there is also some imide-formation.

Specific examples of the process by which the products of this invention may be prepared are as follows.

EXAMPLE 1 A polyisobutenyl succinic anhydride was prepared by the reaction of a chlorinated polyisobutylene with maleic anhydride at 200 C. The polyisobutenyl radical had an average molecular weight of 850 and the resulting alkenyl succinic anhydride was found to have an acid number of 113 (corresponding to an equivalent weight of 500). To a mixture of 500 grams (1 equivalent) of this polyisobutenyl succinic anhydride and 160 grams of toluene there was added at room temperature 35 grams (1 equivalent) of diethylene triamine. The addition was made portionwise throughout a period of 15 minues, and an initial exothermic reaction caused the temperature to rise to 50 C. The mixture then was heated and a water-toluene a'zeotrope distilled from the mixture. When no more water would distill the mixture was heated to C. at reduced pressure to remove the toluene. The residue was diluted with 350 grams of mineral oil and this solution was found to have a nitrogen content of 1.6%.

EXAMPLE 2 The procedures of Example I was repeated using 3| grams (1 equivalent) of ethylene diamine as the amine 5 reactant. The nitrogen content of the resulting product was 1.4%.

EXAMPLE 3 The procedure of Example 1 was repeated using 55.5 grams (1.5 equivalents) of an ethylene amine mixture having a composition corresponding to that of triethylene tetramine. The resulting product had a nitrogen content of 1.9%.

EXAMPLE 4 The procedure of Example 1 was repeated using 55.0 grams (1.5 equivalents) of triethylene tetramine as the amine reactant. The resulting product had a nitrogen content of 2.2%

EXAM PLE 5 ture was heated to distill the watentoluene azeotrope and then to 15 C. at reduced pressure to remove the remaining toluene. The residual polyamide had a nitrogen content of 4.7%.

EXAMPLE 6 The procedure of Example 1 was repeated using 46 grams (1.5 equivalents) of ethylene diamine as the amine reactant. The product which resulted had a nitrogen content of 1.5%.

EXAMPLE 7 A polyisobutenyl succinic anhydride having an acid number of 105 and an equivalent weight of 540 was prepared by the reaction of a chlorinated polyisobutylene (having an average molecular weight of 1,050 and a chlorine content of 4.3%) and maleic anhydride. To a mixture of 300 parts by weight of the polyisobutenyl succinic anhydride and 160 parts of weight of mineral oil there was added at 65-95 C. an equivalent amount (25 parts of weight) of Polyamine H (identified in Example This mixture then was heated to 150 C. to distill all of the water formed in the reaction. Nitrogen was bubbled through the mixture at this temperature to insure removal of the last traces of water. The residue was diluted by 79 parts by weight of mineral oil and this oil solution found to have a nitrogen content of 1.6%.

EXAMPLE 8 A mixture of 2,112 grams (3.9 equivalent) of the polyisobutenyl succinic anhydride of Example 7, 136 grams (3.9 equivalents) of diethylene triamine, and 1,060 grams of mineral oil was heated at 140450 C. for one hour. Nitrogen was bubbled through the mixture at this temperature for four more hours to aid in the removal of water. The residue was diluted with 420 grams of mineral oil and this oil solution was found to have a nitrogen content of 1.3%.

EXAMPLE 9 To a solution of 1,000 grams (1.87 equivalents) of the polyisobutenyl succinic anhydride of Example 7, in 500 grams of mineral oil there was added at 8595 C. 70 grams (1.87 equivalents) of tetracthylene pentamine. The mixture then was heated at 150-165 C. for four hours, blowing with nitrogen to aid in the removal of water. The residue was diluted with 200 grams of mineral oil and the oil solution found to have a nitrogen content of 1.4%.

, EXAMPLE 10 A polypropyenyl succinic anhydride was prepared by the reaction of a chlorinated polypropylene (having a molecular weight of about 900 and a chlorine content of 4%) and maleic anhydride at 200 C. The product had an acid number of 75. To a mixture of 390 grams (0.52 equivalent) of this polypropenyl succinic anhydride, 500 grams of toluene, and 170 grams of mineral oil there was added portionwise 22 grams (0.52 equivalent) of Polyamine H. The reaction mixture was heated at reflux temperature for three hours and water removed from an azeotrope with toluene. The toluene then was removed by heating to 150 C./20 millimeters. The residue was found to contain 1.3 of nitrogen.

EXAMPLE 11 A substituted succinic anhydride was prepared by reacting maleic anhydride with a chlorinated copolymer of isobutylene and styrene. The copolymer consisted of 94 parts by weight of isobutylene units and 6 parts by weight of styrene units, had an average molecular weight of 1,200, and was chlorinated to a chlorine content of 2.8% by weight. The resulting substituted succinic an- I hydride had an acid number of 40. To 710 grams (0.51

equivalent) of this substituted succinic anhydride and 500 grams of toluene there was added portionwise 22 grams (0.51 equivalent) of Polyamine H. The mixture was heated at reflux temperature for three hours to remove by azeotropic distillation all of the water formed in the reaction, and then at 150 C./20 millimeters to remove the toluene. The residue contained 1.1% by weight of nitrogen.

. EXAMPLE 12 A substituted succinic anhydride was prepared by reacting maleic anhydride with a chlorinated copolymer of isobutylene-and isoprene. The copolyrner consisted of 99 parts by weight of isobutylene units and 1% by weight of isoprene units. The molecular weight of the copolymer was 28,000 and the chlorine content of the chlorinated copolymer was 1.95%. The resulting a1- kenyl succinic anhydride had an acid number of 54. To a mixture of 228 grams (0.22 equivalent) of an oil solution of this alkenyl succinic anhydride, 58 grams of additional mineral oil, 500 grams of toluene and 9.3 grams (0.22 equivalent) of Polyamine H was heated at C. for three hours, water being removed from an azeotrope with toluene. When all of the water had thus been removed the toluene was distilled by heating to C./ 20 millimeters. The residue was found to have a nitrogen content of 1.1%.

EXAMPLE 13 A polyisobutenyl succinic anhydride was prepared by the reaction of a chlorinated polysiobutylene with maleic anhydride. The chlorinated polyisobutylene had a chlorine content of 2% and an average molecular weight of 11,000. The polyisobutenyl succinic anhydride had an acid number of 48. A mixture of 410 grams (0.35 equivalent) of this anhydride, 15 grams (0.35 equivalent) of Polyamine H and 500 grams of toluene was heated at reflux temperature for four hours to remove water from an azeotrope with toluene. The toluene then was removed by heating to 150 C./20 millimeters. The nitrogen content of the residue was 1.3%.

EXAMPLE 14 The procedure of Example 5 was repeated except that 0.94 equivalent of Polyamine H was used instead of 1.55 equivalents. The nitrogen content of the product was 3%.

EXAMPLE 15 A polyisobutenyl-substituted succinic acid was prepared by hydrolysis of the corresponding anhydride (prepared in turn by the condensation of a chlorinated poly- 7 isobutylene and maleic anhydride). To 1,152 grams (1.5 equivalents) of a 70% mineral oil solution of this polyisobutenyl succinic acid having an acid number of 62 there was added at room temperature 59.5 grams (1.5 equivalents) of Polyamine H. This mixture was heated at ISO-167 C. for 7 hours during which time a total of 19.5 grams of water was distilled from the mixture. The residue was diluted with 174 grams of mineral oil and then filtered at 150 C. The filtrate had a nitrogen content of 1.6%.

EXAMPLE 16 A mixture of 1,056 grams (2.0 equivalents) of the polyisobutenyl succinic anhydride of the preceding example (in which the polyisobutenyl group has a molecular weight of 850), 89 grams (2.0 equivalents) of di- (-1,2-propylene) triamine (having a nitrogen content of 31.3%), 370 grams of mineral oil and 100 grams of toluene was heated at reflux temperature (ISO-190 C.) for hours. A total of 18 grams of water was collected from the water-toluene azeotrope. The residue was heated to 150 C./20 mm. to remove any last traces of water which might have remained. The nitrogen analysis of this residue was 1.9%.

EXAMPLE 17 A polyisobutylene having an average molecular weight of 50,000 was chlorinated to a chlorine content of by weight. This chlorinated polyisobutylene was reacted with maleic anhydride to produce the corresponding polyisobutenyl succinic anhydride having an acid number of 24. To 6,000 grams (2.55 equivalents) of this anhydride there was added portionwise at 70-105" C. 108 grams (2.55 equivalents) of Polyamine H over a preiod of 45 minutes. The resulting mixture was heated for four hours at l60-l80 C. while nitrogen was bubbled throughout to remove water. When all of the water had been removed the product was filtered and the filtrate found to have a nitrogen content of 0.6%.

EXAMPLE 18 An alkenyl succinic anhydride in which the alkenyl group has less than 50 carbon atoms was prepared from a polyisobutylcne having an average molecular weight This polymer was chlorinated to a chlorine content of 9.7% and then reacted with maleic anhydride. The resulting polyisobutenyl succinic anhydride had an acid number of 190 and an equivalent weight of 300. The procedure of Example 1 was followed using 1.0 equivalent of this polyisobutenyl succinic anhydride and 1.0 equivalentof Polyamine H. The resulting product then was diluted with mineral oil to a 58% solution therein; the nitrogen content was 3.2%.

EXAMPLE 19 Another alkeny] succinic anhydride in which the alkenyl group has less than 50 carbons was prepared by alkylation of maleic anhydride with tetrapropylene. Equivalent amounts of this tetrapropenyl succinic anhydride and triethylene tetramine in toluene were heated at reflux temperature until substantially all of the water was removed. The toluene then was removed by heating at 155% C. under reduced pressure and the residue was dissolved in chlorine oil to a 60% solution. This oil solution was found to have a nitrogen content of 4.8%.

The dispersant qualities of the products prepared by the process of this invention are most striking when used in mineral oil lubricants. These products are miscible in such lubricants in all proportions, and normally they are employed in concentrations ranging from about 0.1% to about 5% by weight of the total lubricant composition. The optimum concentration ordinarily depends upon the nature of the particular base mineral oil stock and the type of service to which the lubricant is to be subjected. The optimum amount will lie within the narrower range of from about 0.5% to about 3%.

As noted before, the addiiton to a lubricating composition of the products of this invention results in a marked improvement in the dispersant qualities of the lubricant, and a mineral oil solution containing only a small percentage of a product of this invention is a satisfactory lubricant in many commercial applications. Most commercial lubricants, however, are subjected to a wide variety of difficult environments and it is necessary for the satisfactory performance of these lubricants to employ more than one type of additive. Thus although the products of this invention are notably effective in the improvement of dispersant properties, particularly for low temperature operations, it frequently is necessary to use this dispersant product in combination with other types of additives such as metallic dispersants, corrosion and oxidation inhibitors, extreme pressure agents, viscosity improvers, pour point depressants, foam inhibitors, etc.

An especially useful combination of additives for use in crankcase lubricants is the combination of the type of additive prepared by the process of this invention and a metallic dispersant. Such metallic dispersants include for example the alkaline earth metal sulfonates, carboxylates and phenates. The alkaline earth metal sulfonates are especially useful in this combination and they include specifically the neutral and basic barium alkylaromatic sulfonates, calcium mahogany sulfonates and calcium alkyl-aromatic sulfonates. The term basic sulfonates is used to denote those compositions which contain a stoichiometrically excessive amount of metal, usually as the metal carbonate, with respect to the sulfonate anion of the composition.

Another very useful combination of additives comprises the type of additive prepared by the process of this invention and a corrosion inhibitor. Such corrosion inhibitors include the metal phosphorodithioates, the various olefin-phosphorus sulfide reaction products and phenolic compounds. A particularly satisfactory metal phosphorodithioate is the zinc dialkyl phosphorodithioate in which the alkyl groups are C -C and a similarly very useful olefin-phosphorus sulfide reaction product is a turpentine-phosphorus pentasulfide condensation product.

The utility of the dispersant additives of this invention is shown by the results of an evaluation of the crankcase lubricants used in taxicabs which had been operated for over 50,000 miles each. In this test ten 6-cylinder 1958 Chevrolet cars (with no oil filters) were operated as a fleet of taxicabs. In each case the crankcase lubricant was a sulfur-refined Mid-Continent petroleum oil having a viscosity of 185 SUS/ F. and a viscosity index of 112, and containing 5.9% by volume of a polyalkylmethacrylate viscosity index improver and 0.59% by volume of a zinc dialkyl phosphorodithioate (the alkyl groups being isobutyl and a mixture of primary amyl). Crankcase oil drains were taken from each car at oilchange intervals of about 3,000 miles of service and these drains combined. A 30-cc. sample of each of the combined drains was mixed with 1% by weight of the dispersant additive to be tested and 2% by weight of water. This mixture then was homogenized, placed in a 100-cc. graduated cone-shaped centrifuge tube and centrifuged for two hours at 1500 r.p.m. The various dispersants were evaluated by noting the volume of deposited sediment in terms of cubic centimeters and also the turbidity of the supernatant oil layer. It is apparent that the more effective dispersants will give test results which show a minimum of deposited sediment and a relatively hazy supernatant oil layer.

The clarity of the supernatant oil layer was determined by the amount of light transmitted through it from a 3-volt, 0.75 watt incandescent bulb.

The results of these tests are shown in Table I.

The dispersant properties of the compositions of this invention may be illustrated also by the results of an oxidation-dispersancy test which is useful as a screening test for determining the effectiveness of the dispersant additive under light-duty service conditions. In this test a 350-cc. sample of a lubricating oil containing the dispersant additive is placed in a 2" x 15" borosilicate tube. A 1%" x 5 /8 SAE 1020 steel panel is immersed in the oil. The sample then is heated at 300 F. for 48 hours while air is bubbled through the oil at the rate of 10 liters per hour. The oxidized sample is cooled to 120 F., homogenized. allowed to stand at room temperature for 24 hours and then filtered through two layers of No. 1 Whatman filter paper at mm. Hg pressure. The weight of the precipitate, washed with naphtha and dried, is taken as a measure of the effectiveness of the dispersant additive, i.e., the greater this weight of precipitate the less effective the dispersant.

Two modifications of the above procedure may be employed; both make the test more severe; one consists of extending the test from 48 hours to 96 hours, and the other involves adding 0.5% of water, based on the weight of the test sample, to the oxidized oil before homogenization.

The lubricating oil employed in this test (Table II) was a Mid-Continent conventionally refined petroleum oil having a viscosity of about 200 SUS/100 F., and containing 0.001% by weight of iron naphthenate (to promote oxidation).

Table II Additive Tested (1.5% by weight of diiiieiita ie tig fifiggg g iree chemical) deposit,

[100 ml. of oil tested None. 144 None. 275 (1)) None. 1, 000 (a,b) Prior art product of Example 18. 738 Prior art product of Example 19. 1,060 (b) Product of Example 1 0.7 (b) Product of Example 2 0.7 (b) Product of Example 3. 1.0 (1)) Product of Example 4. 1.2 (b) Product 01 Example 5. 1. 5 (b) Product of Example 6. 0. 7 (1)) Product of Example 9... 0. 5 (b) Product of Example 10.. 3. 2 (1)) Product of Example 11.. 10.2 (1)) Product of Example 1 19. 5 (b) Product of Example 13.. 2. 7 (1)) Product of Example 14.. 0.3 Product of Example 14.. 1. 2 (h) Product of Example 14.. 1.7 (n,b) Product of Example 15.. 1. 3 (b) Product 01 Example 16 0.9 (b) Modification "3": 96 hours testing.

Modification b: 0.5% of water used in the test.

Further illustration of the usefulness of the products of this invention as dispersants in motor oils was gained from a modified version 1 of the CRC-EX-3 Engine Test. This test is recognized in the field as an important test bywhich lubricants can be evaluated for use under lightduty service conditions. In this particular test the lubricant is used in the crankcase of a 1954 o-cylinder Chevro- 1 Ordinarily this test lusts for 96 hours.

let Powerglide engine for 144 hours under recurring cycling conditions, each cycle consisting of:

2 hours at an engine speed of 500:25 r.p.m. under zero load at an oil sump temperature of 100-125 F.; air-fuel ratio of 10:1;

2 hours at an engine speed of 2500:25 r.p.m-. under a load of 40 brake-horsepower at an oil sump temperaiture of 160170 F.; air-fuel ratio of 16:1;

2 hours at an engine speed of 2500125 r.p.m. under a load of 40 broke-horsepower at an oil sump temperature of 240-250 F.; air-fuel ratio of 16:1.

After completion of the test, the engine is dismantled and various pants of the engine are examined for engine deposits. The lubricant dispersant addition agent is then rated according to (1) the extent of piston ring-filling,

(2) the amount of sludge formed in the engine (on a scale of -0, 80 being indicative of no sludge and 0 being indicative of extremely heavy sludge), and (3) the total amount of engine deposits, i.e., sludge and varnish, formed in the engine (on a scale of -0, 100 being indicative of no deposits and 0 being indicative of extremely heavy deposits). The results are summarized in Table III.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided. the features stated in any of the following claims, or the equivalent of such, be employed.

We therefore particularly point out and distinctly claim as our invention:

1. The product prepared by the process which cornprises mixing a substituted succinic compound selected from the class consisting of substiuted succinic acids having the structural formula noncoo1r HnCOOH and substituted succinic anhydrides having the structural formula R-CHC9\ O CHQCO in which structural formulas R is a large substantially aliphatic hydrocarbon radical having at least about 50 carbon atoms, with at least about one-half an equivalent amount of an ethylene polyamine per equivalent of substituted succinic compound, and heating the resulting mixture to eifect acylaition and remove the water formed theireby.

2. The product prepared by the process which comprises mixing a substituted succinic anhydride having the structural formula R-(lII-Og HQCO/ wherein R is a large, substantially aliphatic hydrocarbon radical having at least about 50 carbon atoms, said suibstituted suocinic anhydride having been prepared by the reaction of maleic anhydride with a high molecular weight olefin; with at least about one-half an equivalent amount, per equivalent of substituted sucoinic anhydride, of an ethylene polyamine, and heating the resulting mixture 11 within the temperature range of from about 80 C. to about 200 C. to effect acylation and to remove the waiter formed thereby.

3. The product prepared by the process which comprises mixing a substituted anhtydride having the structural formula R-CH-CQ wherein R is a large, substantially aliphatic hydrocarbon radical having at least about 50 carbon atoms, said substituted suceinic anthydride having been prepared by the reaction of maleic anhydride with a chlorinated high molecular weight olefin; with at least about onehalf an equivalent amount, per equivalent of substituted succinic anhydride, of an ethylene polyamine, and heating the resulting mixture within the temperature range of from about 80 C. to about 200 C. to effect acylation and to remove the water formed thereby.

4. The product of the process of claim 1 wherein the large, substantially aliphatic hydrocarbon radical is de- 25 J. GREENWALD L M ARCUS, WALTER rived from a polyisobutene.

12 5. The product prepared by the process which comprises mixing a substituted succinic anhydride having the structural formula.

R-CH-CO References Cited by the Examiner UNITED STATES PATENTS 2,490,744 12/49 Trigg et a1 252-34 2,604,451 7/52 Rocchini 252-5l.5 2,638,450 3/53 White et a1. 252-5l.5

NICHOLAS S. RIZZO, Primary Examiner.

Examiners.

MODANCE,

ITED STATES PATENT OFFICE QEWECATE OF. CORRECTIN Patent No. 3,172,892 March 9, 1965 William M. Le Suer et a1.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, lines 60 to- 68, the equations should appear as shown below instead of as in the patent:

IIHCO 4 RCH=CHCHCO RCH=CH2 0 CHCO cn co CHCO\ R-CH=CHCHCO\ RCH CH Cl+ 0- 0 cnco cn co Signed and sealed this 14th day of September 1965.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents

Claims (1)

1. THE PRODUCT PREPARED BY THE PROCESS WHICH COMPRISES MIXING A SUBSTITUTED SUCCINIC COMPOUND SELECTED FROM THE CLASS CONSISTING OF SUBSTITUTED SUCCINIC ACIDS HAVING THE STRUCTURAL FORMULA