US3910845A

US3910845A - Reaction products of formals, acetals and ketals with succinic acid or anhydride as lubricating oil and fuel additives

Info

Publication number: US3910845A
Application number: US372737A
Authority: US
Inventors: Marvin D Coon
Original assignee: Chevron Research and Technology Co
Current assignee: Chevron USA Inc
Priority date: 1973-06-22
Filing date: 1973-06-22
Publication date: 1975-10-07
Anticipated expiration: 1992-10-07

Abstract

The lubricating oil composition, the fuel composition and the fuel concentrate comprising the hydrocarbyl succinate of a formal, acetal or ketal derived from a polyol, wherein the hydrocarbyl substituent contains from 30 to about 300 carbon atoms.

Description

United States Patent [191 Coon [4 Oct. 7, 1975 REACTION PRODUCTS OF FORMALS,

ACETALS AND KETALS WITH SUCCINIC ACID OR ANHYDRIDE AS LUBRICATING OIL AND FUEL ADDITIVES [75] Inventor: Marvin D. Coon, Vallejo, Calif.

[73] Assignee: Chevron Research Company, San

Francisco, Calif.

June 22, 1973 (Under Rule 47) [21] Appl. No.: 372,737

[22] Filed:

[56] References Cited UNITED STATES PATENTS 2,978,469 I 4/1961 Brown et al. 260/496 X 3,632,510 l/l972 LCSUCI 44/70 Primary ExaminerDelbert E. Gantz Assistant ExaminerAndrew H. Metz Attorney, Agent, or FirmG. F. Magdeburger; C. J. Tonkin [57] ABSTRACT The lubricating oil composition, the fuel composition and the fuel concentrate comprising the hydrocarbyl succinate of a formal, acetal or ketal derived from a polyol, wherein the hydrocarbyl substituent contains from 30 to about 300 carbon atoms.

15 Claims, No Drawings REACTION PRODUCTS OF FORMALS, ACETALS AND KETALS WITH SUCCINIC ACID OR ANHYDRIDE AS LUBRICATING OIL AND FUEL ADDITIVES BACKGROUND OF THE INVENTION Much modern research into fuel compositions for the internal combustion engine has for its principal goal the promotion of longer engine life with less maintenance and better performance. This goal is partly achieved by the use of fuel additives which cleanse the carburetor and PCV systems and maintain their cleanliness. Engine performance is also. improved by fuel and lubricant additives'which prevent intake valve deposits and the formation of crankcase sludge and piston varnish. Fuel and lubricating compositions incorporating additives derived from alkenyl succinic acid are disclosed in several patents including US. Pat. No. 3,346,354 (Kautsky and Lindstrom), US. Pat. Nos. 3,447,918, 3,381,022, 3,522,179 and 3,331,776.

SUMMARY OF THE INVENTION The succinates of hydrocarbyl succinic anhydride and acid with ketals, acetals and formals derived from DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Fuel compositions containing a major amount of a liquid hydrocarbon fuel and lO1,5OO ppm of a succinate derived'from hydrocarbyl succinic acid or anhydride and polyol formals, acetals or ketals are superior in intake valve deposit suppression to compositions containing succinic acid esters of the same polyols. Lubricating compositions containing a major amount of an oil of lubricating viscosity and a dispersant amount of the succinatc of the present invention, can also be effective in the internal combustion engine.

FORMALS, ACETALS AND KETALS Formals, acetals and ketals are l,l-dialkoxyalkanes. The following equations typify the formation of acetals, formals and ketals from a polyol. The reaction may proceed through the formation of a hemi-compound, I,

viz:

and/or the reaction forms the cyclic-compound, II, viz:

If R and R are hydrogen, then II represents the formal; if either is an alkyl, the acetal; and if both are alkyl, the ketal. The compound O=CR R of I and II is termed the acetalizing agent. If the polyol contains four or more hydroxyl groups, poly-cyclic compounds can be formed, viz:

R(OH).,+2 o=cR,R R,R,C R CR,R The cyclic-compounds derived from 1,2-glycols are termed dioxolanes. Mixed-compounds, such as mixed acetals, can be prepared by the exchange reaction between a formal, acetal or ketal and another alcohol in the presence of an acid catalyst.

All of the above products are encompassed in the ketals, formals and acetals of this invention. The properties and methods of making these compounds are well known. An introductory discussion can be found in Kirk-Othmers Encyclopedia of Chemical Technology, Vol. I, pp. l07109, 2nd Ed. 1963, Interscience, New York.

In the practice of the present invention R, and'R of the acetalizing agent are independently chosen from hydrogen and hydrocarbyl groups preferably of from 1 to about 10 carbon atoms. R is a hydrocarbyl or oxyhydrocarbyl group preferably of from 2 to about 15 carbon atoms. The formals, acetals and ketals used to prepare the products of the present invention contain at least 3 carbon atoms, and preferably less than about 60 carbon atoms.

The formals, acetals and ketals which find use in the present invention are formed from acetalizing agents such as formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, other C C aldehydes, dimethyl ketone, methylethyl ketone, methylpropyl ketone, acetophenone (methylphenyl ketone), benzophenone (diphenyl ketone) and other C -C ketones; and polyols such as l,2-glycols, e.g., ethylene glycol, 1,3-glycols, etc.; polypropylene glycol, polyethylene glycol, and copolymers of the former and latter; trihydric alcohols, such as glycerol; tetrahydric alcohols, such as pentaerythritol; and other C -C polyols and polymers and copolymers thereof such as the aformentioned polypropylene glycol. These polyols are known materials, many of which are described in Kirk-Othmers Encyclopedia of Chemical Technology, Vol. I, pp. 53 l638. The words polyol and polyhydric alcohol as used herein denote an alcohol containing at least 2 hydroxyl groups and generally an alcohol containing 2 or more hydroxyl groups.

The ketals, acetals and formals of the present invention include, but are not limited to, acetaldehyde ethylene glycol acetal, ethylene glycol formal, dimethyl ketone ethylene glycol ketal, acetaldehyde pentaerythritol acetal, butyl aldehyde pentaerythritol acetal, piperonyl alcohol, pentaerythritol formal and diformal, methyl ethyl ketone pentaerythritol ketal, and so forth.

HYDROCARBYL SUCCINIC ACID AND ANHYDRIDE Hydrocarbyl, as used in this invention in reference to substituents in succinic acid and anhydride, and as used in describing the formals, acetals and ketals, denotes and organic radical composed of carbon and hydrogen which may be aliphatic, alicyclic, aromatic or combinations thereof, e.g., aralkyl. Elements other than carbon and hydrogen, such as chlorine or oxygen, form a minor, insubstantial, sometimes adventitious, component of a hydrocarbyl group. Preferably, the hydrocarbyl group will be relatively free of aliphatic unsaturation, i.e., ethylenic and acetylenic, particularly acetylenic unsaturation.

The hydrocarbyl group in the substituted succinic acid or anhydride will contain from 30 to about 300 carbon atoms and preferably 50-300 carbon atoms. These hydrocarbyl groups are preferably aliphatic, having preferably from O to 2 sites of ethylenic unsaturation and most preferably from O to I such site. Hydrocarbyl groups derived from a polyolefin, itself derived from olefins (normally l-olefins) of from 2 to 6 carbon atoms (ethylene being copolymerized with an olefin of at least 3 carbon atoms), or from a high molecular weight petroleum-derived hydrocarbon, are preferred, and of these polyisobutenyl is most preferred. Illustrative sources for the high molecular weight hydrocarbyl substituents are petroleum mineral oils, such as naphthenic bright stocks, polypropylene, polyisobutylene, poly-l-butene, copolymers of ethylene and propylene, polyl -pentent, poly-4-methyll-pentene, polyl hexene, poly-3-methylbutcne-l etc.

The hydrocarbyl-substituted succinic acid and anhydrides are preferably derived from the addition of a polyolefin to maleic acid or anhydride, in which case the double bond of the maleic acid anhydride becomes saturated and there remains in the hydrocarbyl at least l olefinic double bond. If it is desired, the olefinic bond may be saturated by hydrogenation. A typical preparation of a hydrocarbyl succinic anhydride has been described, for example, in US. Pat. No. 3,024,195. As used herein, the words succinic acid or succinic anhydride denote the entire class of succinic acid generating compounds, including the acid, anhydride, acid halide, or ester, which function to yield the products of the present invention.

REACTION CONDITIONS Because of the complex nature of the acetals, formals, and ketals, and their reaction products with a dicarboxylic acid such as succinic acid, the succinates of the present invention cannot be described, with practicality, in terms of a reasonable number of structural formulae. However, for purposes of illustration, it is suggested that the reaction of a hydrocarbyl succinic anhydride with, for example, pentaerythritol diformal proceeds, schematically, as follows:

R is the hydrocarbyl substituent and x is believed to have a value from 1 to about l0. It is not known whether substantial amounts of acetalizing agent remain incorporated as an intermolecular linking agent in the final product as shown.

Reaction conditions are generally chosen so as to accomplish this reaction in a reasonable amount of time. Such conditions include the reaction of the hydrocarbyl succinic anhydride or acid with the acetal, formal, or ketal in a mo] ratio of about 1:3 to 3: l at a temperature of from about C to about 250C preferably from lO0-200C, for from about 0.5 to about 20 hours, preferably from about i to about 4 hours. The reaction may be carried out neat, or in the presence of a suitable aliphatic or aromatic organic solvent, such as petroleum oil, hexane, toluene, or mixtures thereof. It is preferred but not necessary to use an acid catalyst for the reaction, such as BF, preferably as BF -etherate, but other acid catalysts can be utilized in addition to, or in replacement of, BF;,. The dispersants of the present invention have usually been prepared by reacting the pure formal, acetal or ketal with hydrocarbylsubstituted succinic acid or anhydride. However, this is prohibitively expensive if it is necessary to isolate and purify the pure formal, acetal or ketal before use. As shown in the following examples, reactions can be carried out using the crude formal, acetal or ketal obtained by reacting the polyol with the acetalizing agent, e.g., paraforrnaldehyde. After water stops evolving in the acetalizing reaction, the succinic anhydride and catalyst are added. Infrared spectra show that essentially the same product is obtained. The reaction can also be carried out by a one-step charge of reactants, that is, succinic anhydride or acid, polyol and acetalizing agent in mol ratio of about O.333:1:l are mixed together at a temperature of from about 60 to about 250C, preferably from l0O-200C, for from about 0.5 to about 20 hours, preferably from about 1 to about 4 hours, preferably in the presence of an acid catalyst. Alternatively, the reaction can be carried out in the reverse order, by combining the acid or anhydride with the polyol at 60250C for 0.5-20 hours, followed by addition of the acetalizing agent and reaction under the conditions previously described. Usually, the products are given a thorough aqueous wash to remove the acid catalyst. Alternatively, or in addition thereto, an approximately equivalent or excess amount of ammonia or amine is introduced to neutralize the acid catalyst by forming an insoluble salt which is easily removed from the medium by filtration or decantation.

EXAMPLE I 1,000 grams of polybutenyl succinic anhydride of approximate number average molecular weight 1,000 (about a 50% oil solution, about 0.46 mol, 40 mg.KOH/g acid number, 2.5 weight percent oxygen) I I g -OC c o c o )3 H O O R was combined with pentaerythritol diformal (134 g, 0.84 mol) and ml of BF;; etherate. The mixture was heated to 95-l00C for 1.5 hours. After cooling, the product was diluted with an equal volume of mixed hexanes and washed three times with an amount equal to about one-half the organic layer of a solution of 60 percent water, percent ethanol, and 10 percent nbutanol. The organic layer was stripped on a solvent stripper at 5 mm and 90C to yield 1,050 g of product having the following analysis: acid number, 1 1.2 mg.KOH/g; hydroxyl number (corrected for the presence of acid), 17.2 mg.KOH/g; percent by weight oxygen, 4.3%; percent by weight oxygen calculated for product containing 1 mol of diformal per mol of polybutcnyl succinic acid, 3.75%. The infrared spectrum of the product shows an absorption at 1,745 cm; no hydroxyl absorption is present in the 3,2003,800 cm range.

EXAMPLE 2 Polyisobutenyl succinic anhydride, as described previously (600 grams, about 0.27 mol), and 2,2-dimethyl- 1,3-dioxolane-4-methano1 (ketal of acetone and glycerol 109 g, 0.9 mol, were heated together at 200C for 2 hours. The cooled mixture was worked up as described in Example 1 to give 635 grams of product having the following analysis: acid number, 10 mg.KOH/g; hydroxyl number (corrected for the presence of acid), 26 mg.KOH/g; weight percent oxygen, 4.3%; weight percent oxygen calculated for 1 mol of ketal per mol of anhydride, 3.88%.

EXAMPLE 3 Polybutenyl succinic anhydride described above (600 g, 0.27 mol) and piperonyl alcohol (the formal of a carbinol-substituted catechol), 91 g, 0.6 mol, were heated at 200230C for 2 hours. The mixture was worked up as described in the first example to give 631 g of product having the following analysis: acid number, 1 1 mg.KOH/g; hydroxyl number (corrected for the presence of acid), 6.2 mg.KOH/g; weight percent oxygen, 4.8%; weight percent oxygen calculated for 2 mols of formal per mol of anhydride, 4.47%.

EXAMPLE 4 3,000 grams of PlBSA (polyisobutenyl succinic anhydride) of approximate number average molecular weight 1,000 (50% oil solution, about 1.5 mols, 40 mg.KOH/g acid number, 2.5% O) was combined with 378 grams (2.0 mols) of pentaerythritoldiacetal and 30 ml of BF; etherate. The mixture was heated to 90-1 10C for 2 hours; after cooling, the mixture was diluted with an equal volume of mixed hexanes and washed three times with an amount equal to about onehalf the organic layer of a solution of 60% water, 30%- ethanol, and 10% isobutanol. The organic layer was stripped on a solvent stripper at 5 mm and 90C to yield 3222 grams of product having the following analysis: Acid No., mg.KOH/gram, 10.1; Hydroxyl No., mg.KOH/gram, 32.1 (all hydroxyl numbers have been corrected for presence of acid).

EXAMPLE 5 PlBSA as described above (468 g, about 0.21 mol) was mixed with pentaerythritoldiacetal (40.0 g, about 0.21 mol), and BE, etherate (10 ml). The mixture was heated with stirring to 95l 10C for 1.5 hours. After cooling, 400 m1 of mixed hexanes were added, followed by the addition of ammonia gas to neutralize the acid. The resulting solution was filtered, and the filtrate stripped on the solvent stripper to yield 502 grams of product having the following analysis: Acid No, mg.KOH/g, 17.0; Hydroxyl No., mg.KOH/g, 24.0; Nitrogen, 0.16.

EXAMPLE 6 Pentaerythritol (150 g, about 1.1 mols), anhydrous magnesium sulfate (264 g, about 2.2 mols), p-toluenesulfonic acid (3 grams), and 600 m1 of acetone were heated at reflux with stirring for 20 hours. The mixture was filtered and the filter cake extracted with 1 liter of hot toluene. The extracts and filtrate were combined and stripped on the solvent stripper. The resulting white solid was purified by extraction with 2 liters of boiling hexane. The hot extract was allowed to stand until all insoluble material settled to the bottom. The clear extract was decanted and stripped on the solvent stripper to yield 97 grams of white crystalline pentaerythritoldiacetoneketal. An infrared spectrum of the material is completely free of hydroxyl absorption.

PlBSA (950 g, about 0.47 mol), pentaerythritoldiacetoneketal g, about 0.47 mol), and BE, etherate were heated with stirring to 100C for 3 /2 hours. The mixture was diluuted with mixed hexanes and worked up as described in Example 4 to yield 944 grams of product having the following analysis: Acid No., mg.KOH/gram, 7.6; Hydroxyl No, mg.KOH/g, 37.6.

EXAMPLE 7 Pentaerythritol (3 1.5 g, about 0.35 mol paraformaldehyde (21.6 g, about 0.24 mol), concentrated HCl (5 ml), and 200 m1 of toluene were heated to reflux. Water was removed azeotropically. After 40 min., water ceased to come over. PlBSA (500 g, about 0.23 mol) as described above and BF etherate 15 ml) were added to the mixture. The resulting solution was heated at reflux for 1.5 hours then cooled, diluted with mixed hexanes, and worked up as in Example 4 to yield 530 grams of product having the following analysis: Acid No., mg.KOH/g, 7.1; Hydroxyl No., mg.KOH/g, 36.1.

EXAMPLE 8 PlBSA (500 g, about 0.23 mol) as described above, pentaerythritol (31.5' g, about 0.35 mol), paraformaldehyde (21.6 g, about 0.24 mol), concentrated HCl (6 m1), toluene ml), and xylene (250 ml) were heated to reflux with stirring. Water 19.2 grams) was removed azeotropically over a 1.25-hour period. Solvent was removed by distillation until the temperature increased to 150C. The temperature was held at l 15C for 2 hours then the mixture was cooled, diluted with mixed hexanes, and worked up as in Example 4 to yield 531 grams of product having the following analysis: Acid No., mg.KOH/g, 1 1.6; Hydroxyl No., mg.KOH/g, 23.6.

COMPOSITIONS Depending upon the particular application of the additives of this invention, the reaction may be carried out in the medium in which it will ultimately find use and be formed in concentrations which provide a concentrate of the succinate. Thus, the final composition may be in a form to be used directly upon dilution in fuels or lubricants. The succinates of this invention will generally be employed in hydrocarbon liquid fuels and oils of lubricating viscosity.

The additives may be formulated as a fuel concentrate using a suitable solvent, preferably an aromatic hydrocarbon solvent such as benzene, toluene, xylene or higher boiling aromatic or aromatic thinner. Ali phatic alcohols of about 3-5 carbon atoms such as isopropanol, isobutanol, n-butanol, and the like, also in combination with hydrocarbon solvents are also suitable for use with the additive. Other polymeric materials may also be used in conjunction with the additives of this invention, e.g., polyisopropylene.

The lubricating oil can be a relatively inert and stable fluid of lubricating viscosity. Such lubricating fluids generally have viscosities of 3550,()()() Saybolt Universal Seconds (SUS) at 100F. The fluid medium or oil may be derived from either natural or synthetic sources. Included among the natural hydrocarbonaceous oil are paraffin-base, naphthenic-base or mixed base oils. Synthetic oils include polymers of various olefms, generally of from 2-6 carbon atoms, alkylated aromatic hydrocarbons, etc. Non-hydrocarbon oils include polyalkylene oxides, such polyethylene oxide, aromatic ethers, silicones, etc. The preferred media are the hydroearbonaceous oils, both natural and synthetic. Preferred are those hydrocarbonaceous oils having viscosity of about l4,000 SUS at 100F and particularly those having viscosities of about 2()02,000 SUS. The lubricating oil will be present at 75 or greater percent by weight of the final lubricant composition. In concentrates, however, the oil may be present as l075 percent by weight. These concentrates are diluted with additional oil prior to being placed in service to obtain the requisite concentration. Unlike fuel concentrates, it is usually unnecessary to provide a solvent other than the lubricating oil itself.

The liquid hydrocarbon fuels of the present composition encompass fuels boiling in the gasoline and diesel oil range, e.g., having ASTM D-86 90% points for about 200F to about 700F and generally boiling from about l00F to about 750F. In the fuel, the concentration of the succinate will generally be at least ppm and usually not more than 4,000 ppm, more usually in the range of from about l0l,5000 ppm. In fuel concentrates, the succinates will range from about 1-90 weight percent, more usually from about 5-30 weight percent and generally not exceeding 80 weight percent. In gasoline fuels, other fuel additives may also be included such as antiknock agents, e.g., tetramethyl lead, tetraethyl lead. Also included may be lead scavengers such as aryl halides, e.g., dichlorobenzene or alkyl halides, e.g., ethylene dibromide. A non-volatile lubricating mineral oil, e.g., petroleum spray oil, having a viscosity at 100F of l,O002,000 SUS is a suitable oil additive for the gasoline composition used with the reaction products of the present invention and its use is preferred. Polymeric materials as mentioned above, such polyolefins and glycols such as polypropylene glycol can also be used. These materials are believed to act as a carrier for the additive and assist in removing and preventing deposits. They are employed in amounts of from about 0.05 to 0.5 percent by volume, based on the final gasoline composition.

Other additives will also be present in the lubricating oil compositions of this invention. .Materials may be added for enhancing the EP properties of the additive or providing other desirable properties to the lubricating medium. These include metallic detergents such as the overbased sulfonates and phenates, rust and corrosion inhibitors, antioxidants, oiliness agents, foam inhibitors, antiwear agents, viscosity index improvers, pour point depressants, etc. Usually, these will be in the range of from about 05 percent by weight, more generally in the range from about 02 percent by weight of the total composition. Typical additional additives found in lubricating oil compositions of the present invention include lead naphthenates, phenolic and aryl amine antioxidants, zinc dihydrocarbyl dithiophosphates, carbonatedsulfuriZed-calcium polypropylene phenate, etc.

EVALUATION The succinates of the present invention were tested for their ability to maintain cleanliness of internal combustion engines as fuel and lubricating oil additives in the following tests.

To measure the ability of a gasoline or lubricating oil additive to ensure engine cleanliness, the following Laboratory Dispersancy Test (LDT) is used. A laboratory solvent consisting of 25 percent xylene and percent hexane by volume is used to prepare solutions of the additive to be tested. Solutions (25 ml) are placed in lounce vials. A given quantity of chloroformsoluble engine sludge is added (0.5 ml of a solution containing 4 grams of sludge per ml of chloroform), and the vials are shaken vigorously for 5 seconds. The vials are allowed to stand for 2 hours and then photographed to record the results. The cut-off concentration is the lowest concentration wherein the solution is able to suspend or disperse a reasonable amount of the material resulting in the solution having a dark and turbid appearance. An effective additive will have a low cut-off concentration and a poor additive will have a high cut-off concentration. The precipitated engine sludge is obtained from engines in actual service by scraping areas containing heavy deposits of sludge. The sludge is washed with hexane to remove oil and hydrocarbon-soluble substances. The mixture is centrifuged and the hexane-soluble faction is decanted. A second washing with hexane is performed and the insolubles are stirred with chloroform, centrifuged and the chloroform decant stripped on a solvent stripper to give a dry, black granular material. This is the material used in the LDT. The dry material is dissolved in chloroform before use to give a solution of the desired con centration.

Table I illustrates the difference between the succinic anhydride-acetal, ketal or formal succinates of the present invention and the ordinary succinic acid dispersants of the prior art. In Table I PIBSA is polyisobutenyl succinic anhydride of the same average molecular weight as used in the synthesis of Examples 1, 2 and 3, the products of which are also shown in Table I. PIB- SA-ester is the polyisobutenyl succinic anhydridepentaerythritol ester which is a known dispersant additive for lubricating oils. Note that of this group of compounds, the PIBSA-ester is the most dispersant, having the lowest cut-off concentration in ppm and the unreacted PIBSA is the next most-effective dispersant. The succinates of Examples 1-3 display appreciably poorer dispersancy. The reason for the poor dispersancy is related to the acid and hydroxyl numbers either one of which is lower for the products of Examples l3 than it is for PIBSA and the PIBSA-ester. The blocking of the free acid group of the acid,'or of the free hydroxyl groups of the acid-polyol ester serve to drastically decrease the dispersancy of the additive. It is believed that the formal, acetal and ketal succinates of the present invention, prepared as described, have relatively little hydroxyl present as evidenced by their relatively low hydroxyl numbers, typically between 4 mg.KOH/g and 30 mg.KOH/g. It is believed that the absence of hydroxyl groups prevents hydrogen bonding between dispersant and sludge precursors. Hydroxyl numbers are determined, in general, by adding acetic anhydride in pyridine solution to the material, acetylating the hydroxyl groups and releasing equivalent acetic acid which is subsequently titrated with KOH.

The functionality of the succinic anhydride-formal, acetal or ketal succinates arises upon hydrolysis of the material, whereupon it becomes a functioning dispersant. The materials are not believed to act as dispersants as originally put into the fuel or lubricating oil but become dispersants upon hydrolysis in the presence of acids and water. Consequently, they have been termed hydrolytically activated dispersants. A laboratory simulation of this process was carried out in order to show that dispersancy increases as hydrolsis occurs. A solution of percent by weight active additive of Example 1 was placed in 1,700 SUS at 100F neutral petroleum oil and was heated at 200F with rapid stirring in the presence of a small amount of water (0.7%) and a trace of mixed mineral and organic acids (0.3%). Samples Corrected for presence of acid; corrected hydroxyl number hydroxyl number found ucid number.

The additive of Example 1 increased in dispersancy to 800 ppm in about 8 hours, as did other hydrolytically activatable dispersants in this test. Hydrolysis was stopped at this point and no attempt was made to see whether the hydrolytically activatable dispersants could be made as effective as the best known dispersants by this means. Rather, they were tested under conditions of actual usage in the 8-hour Engine Dispersancy Test (EDT).

The EDT is conducted in a 1962 Chevrolet 6- cylinder 235-CID engine using a 480 neutral lubricating oil containing 50 mM/kg of zinc dithiophosphate. The test duration is 8 hours under the following operating cycle: time, seconds/engineload, bhp/rpm is lO/idle/700, SOUS/2,500, 30/idle/700, 150/75/2,500, the water temperature is 110F and the oil temperature is 180F. At the completion of each test, the used oil is analyzed for the amount of hexane insolubles. 10 ml of the oil is diluted to 50 ml with 0.45 micron-filtered hexane and filtered through a 3-micron filter followed by washing with hexane until oil-free and drying in an oven at 200F for 10 minutes. The amount of insolubles is reported in milligrams per 10 milliliters of used oil. In this test, the smaller the amount of hexane insolubles collected, the better the dispersancy of the dispersant additive in the gasoline. The results are given in Table II.

TABLE II EDT, mg Sludge* Example I 9.6 Example 2 10.6 Example 3 39.4 PIBSA-Ester 6.0 Base Fuel 4L3 mg of sludge in 10 ml of oil at 200 ppm additive in fuel The results of Table II demonstrate that under actual operating conditions, the succinate dispersants of the present invention are effective in the crankcase.

Since succinic acid esters of polyols have been noted for their inability to maintain intake system cleanliness, and can even contribute to the formation of intake valve deposits, a 10-hour intake deposit test was perfonned. The engine used in this test is a Waukesha ASTM-CFR single-cylinder engine. Upon completion of the test, the intake valve is removed, washed with hexane, and weighed. The deposits are removed with a wire brush and the valve re-weighed. The difference between the two weights is the weight of deposit. Operating conditions include an engine speed of 1800 rpm, a water temperature of 212F, a manifold vacuum of 15 inches of Hg, 21 fuel-air mixture temperature of F, an air-fuel ratio of l4, and intake spark timing, 15BTC. All fuel samples except the base fueltest contain 250 ppm of the additive. All samples contain 1,000 ppm of 1,700 SUS at I00F neutral petroleum oil as a carrier oil. The results are given in Table III.

TABLE III Intake Valve Deposits, mg

Table III demonstrates the surprising ability of the hydrolytically activatable succinates of the present invention to maintain intake valve cleanliness under actual operating conditions. In this property they are surprisingly superior to succinic acid esters of polyols and comparable to the polybutene amine fuel detergents.

In order to test the hydrocarbyl-substituted succinates of ketal, formals and acetals as lubricating oil dispersant additives the following test was performed.

The 180 BMEP (Brake Mean Effective Pressure in psi) Caterpillar test is a severe engine test for lubricating oil additives. The 180 BMEP Caterpillar test conditions are for a supercharged Caterpillar engine, wherein the pressure of the supercharged air is 70 in. Hg. abs., the water temperature of the cooling jacket is F, the air temperature is 255F, the oil temperature at the bearing is 205F, the sulfur content of the fuel is 0.4%, the speed of the engine is 1800 rpm, and the rate of fuel input is at a rate which provides 7,460 Btu per minute. The test is carried out for a stated number of hours as indicated in Table IV. Groove deposits are then rated on a range of 0-100, 100 being com- TABLE IV 180 BMEP DIESEL RESULTS Addi- Undertivc Hrs Grooves Lands head Ex. I 60 70.4 l5.6-0.5-0.5 330-l'l0 9.0

I80 89.6-22.5-().5-O.5 465-20-25 6.3 PlBSA 60 563-1 6-0.S 0.5 l10-l0 4.8 ester 120 77.0-2.0-0.5-0.5 40-10-10 6.7

The additives of the present invention show appreciable activity in maintaining engine cleanliness. The test results of Table IV include results for a PIBSA-ester dispersant (polyisobutenyl succinate of pentaerythritol The table shows the activity of the present additive as a dispersant lubricating oil additive and its ability to maintain engine cleanliness, especially in the underhead.

While the character of this invention has been described in detail with several examples, this has been done by way of illustration rather than limitation. It is apparent to those skilled in the art that numerous modifications and variations of illustrative examples can be made in the practice of the invention.

1 claim:

1. A fuel composition comprising a major amount of a normally liquid hydrocarbon fuel and from 10 ppm to 1,500 ppm of a reaction product of (i) a hydrocarbylsubstituted succinic acid or anhydride, wherein said hydrocarbyl substituent contains from about 30 to about 300 carbon atoms, and (ii) a formal, acetal, or ketal of a polyol and an acetalizing agent selected from the group consisting of C ,-C alkyl aldehydes, C -C alkyl ketone, and mixtures thereof; wherein the ratio of said succinic acid or anhydride to said formal, acetal or ketal is from about 1:3 to 3:1 and wherein the reaction takes place at a temperature from about 60C to about 250C.

2. A fuel composition according to claim 1, wherein said formal, acetal, or ketal is derived from a C -C polyol.

3. A fuel composition according to claim 1, wherein said hydrocarbyl substituent is a polyolefin, itself derived from C C olefins, with the proviso that ethylene is copolymerized with a higher olefin.

4. A fuel composition according to claim 3, wherein said polyolefin is polybutene or polypropylene.

5. A fuel composition according to claim 1, wherein said formal, acetal, or ketal is derived from pentaerythritol.

6. A fuel composition according to claim 5, wherein said formal of pentaerythritol is the diformal.

7. A fuel concentrate composition having a suitable solvent for admixture with a normally liquid hydrocarbon fuel and from lO- weight percent of a reaction product of (i) a hydrocarbyl-substituted succinic acid or anhydride, wherein said hydrocarbyl substituent contains from about 30 to about 300 carbons and (ii) a formal, acetal, or ketal of a polyol and an acetalizing agent selected from the group consisting of C C alkyl alehyde, C C alkyl ketone, and mixtures thereof; wherein the ratio of said succinic acid or anhydride to said acetal, formal or ketal is from about 1:3 to 3:1 and wherein the reaction takes place at a temperature of about 60C to about 250C.

8. A fuel concentrate composition having a suitable solvent for admixture with a hydrocarbon fuel and from 10-70 weight percent of a hydrocarbyl-substituted succinate according to claim 7, wherein said formal, acetal, or ketal is derived from a C -C polyol.

9. A fuel concentrate composition having a suitable solvent for admixture with a hydrocarbon fuel and from lO7O weight percent of a hydrocarbyl-substituted succinate according to claim 8, wherein said formal, acetal, or ketal is derived from pentaerythritol.

10. A lubricating oil composition comprising a major amount of an oil of lubricating viscosity and from 0.1-5 percent by weight of a reaction product of l) a hydrocarbyl-substituted succinic acid or anhydride, wherein said hydrocarbyl substituent contains from about 30 to about 300 carbons, and (2) a formal, acetal or ketal of a polyol and an acetalizing agent selected from the group consisting of C,C alkyl aldehyde, C -C alkyl ketone, and mixtures thereof; wherein the ratio of said succinic acid or anhydride to said acetal, formal or ketal is from about 1:3 to 3:1 and wherein the reaction takes place at a temperature of about 60C to about 250C.

11. A lubricating oil composition according to claim 10, wherein said formal, acetal, or ketal is derived from a C C polyol.

12. A lubricating oil composition according to claim 10, wherein said hydrocarbyl substituent is a polyolefin, itself derived from C -C olefins, with the proviso that ethylene is copolymerized with a higher olefin.

13. A lubricating oil composition according to claim 12, wherein said polyolefin is polybutene or polypropylene.

14. A lubricating oil composition according to claim 10, wherein said formal, acetal, or ketal is derived from pentaerythritol.

15. A lubricating oil composition according to claim 14, wherein said formal of pentaerythritol is the diformal.

Claims

1. A FUEL COMPOSITION COMPRISING A MAJOR AMOUNT OF A NORMALLY LIQUID HYDROCARBON FUEL AND FROM 10 PPM TO 1, 500 PPM OF A REACTION PRODUCT OF (I) A HYDROCARBYL-SUBSTITUTED SUCCINIC ACID OR ANHYDRIDE, WHEREIN SAID HYDROCARBYL SUBSTITUENT CONTAINS FROM ABOUT 30 TO ABOUT 300 CARBON ATOMS, AND (II) A FORMAL, ACETAL, OR KETAL OF A POLYOL AND AN ACETALIZING AGENT SELECTED FROM THE GROUP CONSISTING OF C1-C12 ALKYL ALDEHYDES, C3-C24 ALKYL KETONE, AND MIXTURES THEREOF, WHEREIN THE RATIO OF SAID SUCCINIC ACID OR ANHYDRIDE TO SAID FORMAL, ACETAL OR KETAL IS FROM ABOUT 1:3 TO 3:1 AND WHEREIN THE REACTION TAKES PLACE AT A TEMPERATURE FROM ABOUT 60*C TO ABOUT 250*C.

2. A fuel composition according to claim 1, wherein said formal, acetal, or ketal is derived from a C2 -C15 polyol.

3. A fuel composition according to claim 1, wherein said hydrocarbyl substituent is a polyolefin, itself derived from C2-C6 olefins, with the proviso that ethylene is copolymerized with a higher olefin.

7. A fuel concentrate composition having a suitable solvent for admixture with a normally liquid hydrocarbon fuel and from 10-70 weight percent of a reaction product of (i) a hydrocarbyl-substituted succinic acid or anhydride, wherein said hydrocarbyl substituent contains from about 30 to about 300 carbons and (ii) a formal, acetal, or ketal of a polyol and an acetalizing agent selected from the group consisting of C1-C12 alkyl alehyde, C3-C4 alkyl ketone, and mixtures thereof; wherein the ratio of said succinic acid or anhydride to said acetal, formal or ketal is from about 1:3 to 3:1 and wherein the reaction takes place at a temperature of about 60*C to about 250*C.

8. A fuel concentrate composition having a suitable solvent for admixture with a hydrocarbon fuel and from 10-70 weight percent of a hydrocarbyl-substituted succinate according to claim 7, wherein said formal, acetal, or ketal is derived from a C2-C15 polyol.

9. A fuel concentrate composition having a suitable solvent for admixture with a hydrocarbon fuel and from 10-70 weight percent of a hydrocarbyl-substituted succinate according to claim 8, wherein said formal, acetal, or ketal is derived from pentaerythritol.

10. A lubricating oil composition comprising a major amount of an oil of lubricating viscosity and from 0.1-5 percent by weight of a reaction product of (1) a hydrocarbyl-substituted succinic acid or anhydride, wherein said hydrocarbyl substituent contains from about 30 to about 300 carbons, and (2) a formal, acetal or ketal of a polyol and an acetalizing agent selected from the group consisting of C1-C12 alkyl aldehyde, C3-C24 alkyl ketone, and mixtures thereof; wherein the ratio of said succinic acid or anhydride to said acetal, formal or ketal is from about 1:3 to 3: 1 and wherein the reaction takes place at a temperature of about 60*C to about 250*C.

11. A lubricating oil composition according to claim 10, wherein said formal, acetal, or ketal is derived from a C2-C15 polyol.

12. A lubricating oil composItion according to claim 10, wherein said hydrocarbyl substituent is a polyolefin, itself derived from C2-C6 olefins, with the proviso that ethylene is copolymerized with a higher olefin.