AU657356B2 - Compositions for control of induction system deposits - Google Patents

Description

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION 657356 NAME OF APPLICANT(S): Ethyl Petroleum Additives, Inc.

ADDRESS FOR SERVICE: DAVIES COLLISON CAVE o Patent Attorneys 1 Little Collins Street, Melbourne, 3000.

i INVENTION TITLE: Compositions for control of induction system deposits r a The following statement is a full description of this of performing it known to me/us:invention, including the best method -la- This invention relates to controlling fuel induction system deposits in internal combustion engines. More particularly this invention relates to detergent/dispersant compositions and to gasoline type fuels and fuels mixtures for internal combustion engines, said fuels and mixtures capable of reducing or at least minimizing the mount of intake valve deposits formed during engine operation.

A problem frequently encountered in the operation of internal S. combustion engines is the formation of undesirable amounts of engine deposits, such as fuel injector and intake valve deposits, which form during engine operation.

:.An object of this invention is to provide compositions capable of reducing the S. severity of this problem. Another object is to provide compositions which also reduce deposits which are already present due to prior operation with fuels compositions which have formed such deposits.

As the emphasis has shifted to providing fuels and fuel mixtures which are more environmentally "friendly", and as more vehicles are being equipped with fuel injectors to increase the efficiency and further reduce emissions from internal combustion engines, a need has developed for fuels and fuel mixtures which reduce and/or eliminate the amount of deposits which accumulate on fuel injectors and •d '20 intake valves. To reduce the amount of deposits on the fuel injectors, detergent additives designed for this purpose have been added to fuel compositions. While these detergents provide a significant reduction in the deposits which heretofore have hindered the operation of fuel injected internal combustion engines, such formulations may not provide the most desirable detergent effect for inhibiting and/or cleaning deposits on other internal engine parts, intake vaLtes. There is a need therefore for detergents which not only keep fuel injectors clean but which effectively control deposits on intake valves as well as other engine parts of internal combustion engines.

This invention pridesfu diti entrtoa /^P^A3O a detergent/dispers the repidict, of polyami.ne and at least -2- This invention provides a motor fuel containing a major amount of unleaded gasoline and a deposit controlling amount of up to 1500 parts per million parts of the fuel of a combination of: a) 1 part by weight of the reaction product of alkylene polyamine and (ii) at least one substituted succinic acylating agent wherein the molar ratio of the acylating agent to polyamine in the reaction product is in the range of 1.5:1 to 2.2:1, and wherein the substituent is derived from polyisobutene having a number average molecular weight as determined by gel permeation chromatography in the range of 700 to 1200; and b) from 1.5 up to 4 parts by weight of a mineral oil having a viscosity index of less than 90 and a volatility of less than 50% as determined by a method described herein.

This invention also provides a method for controlling deposits which may develop on internal parts of a gasoline engine comprising providing for use as a gasoline engine fuel, a composition comprising a major amount of unleaded gasoline and a 15 deposit controlling amount of up to 1500 parts per million parts of the fuel of a combination of: a) 1 part by weight of the reaction product of alkylene polyamine and (ii) at least one substituted succinic acylating agent wherein the molar ratio of the acylating agent to polyamine in the reaction product is in the range of 1.5:1 to 2.2:1, and wherein the substituent is derived from polyisobutene having a number average molecular weight as determined by gel permeation chromatography in the range of 700 to 1200; and b) from 1.5 up to 4 parts by weight of a mineral oil having a viscosity index S. of less than 90 and a volatility of less than 50% as determined by a method described herein.

25 This invention further provides a metal-free fuel additive concentrate which comprises per each 100 parts by weight thereof: a) from 10 to 50 parts by weight of the reaction product of alkylene polyamine and (ii) at least one substituted succinic acylating agent wherein the molar ratio of the acylating agent to polyamine in the reaction product is in the range of 1.5:1 to 2.2:1, and wherein the substituent is derived from polysiobutene having a number 941222,p:\opcr\dab,23525.spe,2 2aaverage molecular weight as determined by gel permeation chromatography in the range of 700 to 1200; b) up to 75 parts by weight of a mineral oil having a viscosity index of less than 90 and a volatility of less than 50% as determined by a method described herein; c) 0 to 5 parts by weight of antioxidant; d) 0 to 10 parts by weight of demulsifier; e) 0 to 75 parts by weight of aromatic hydrocarbon solvent; and f) 0 to 5 parts by weight of corrosion inhibitor; the weight ratio of b) to a) corresponding to from 1.5 up to 4 parts by weight of b) per part by weight of a).

The deposit control mixture may further comprise: a) an antioxidant; b) a demulsifier; c) a corrosion inhibitor; d) an aromatic hydrocarbon solvent; or e) any combination of any two or three or all four of components and wherein the weight ratio of the reaction product of polyamine and at least one substituted succinic acylating agent, to the mineral oil is in the range of from 1:1.8 to 1:2.2 and wherein the molar ratio of acylating agent to polyamine is 1.8:1.

These and other embodiments of this invention will be apparent from the ensuing S. description and appended claims.

Detergent/dispersant. As noted above, the fuel additive concentrate of this invention comprises as a detergent/dispersant, the reaction product of alkylene polyamine and (ii) at least one substituted succinic acylating agent; and a mineral oil

S

25 having a viscosity index of less than 90 and a volatility of less than 50% as determined by the test method described herein. The polyamine reactant may be one or more alkylene polyamine(s), which 941 222,p:\opcrdab,2352S.spe,2 Case EI-6371 -3polyamines may be linear, branched, or cyclic; or a mixture of linear, branched and/or cyclic polyamines and wherein each alkylene group contains from 1 to carbon atoms. A preferred polyamine is a polyamine containing from 2 to nitrogen atoms per molecule or a mixture of polyamines containing an average of from 2 to 10 nitrogen atoms per molecule. A particularly preferred polyamine is a polyamine or mixture of polyamines having from 3 to 7 nitrogen atoms with triethylene tetramine or a combination of ethylene poly-amines which approximate triethylene tetramine being the most preferred. In selecting an appropriate polyamine, consideration should be given to the compatibility of the resulting detergent/ dispersant with the fuel mixture with which it is mixed.

Ordinarily the most highly preferred polyamine, triethylene tetramine, will comprise a commercially available mixture having the general overall composition approximating that of triethylene tetramine but which can contain minor amounts of branched-chain and cyclic species as well as some linear poly- 15 ethylene polyamines such as diethylene triamine and tetraethylene pentamine.

For best results, such mixtures should contain at least 50% and preferably at least 70% by weight of the linear polyethylene polyamines enriched in triethylene tetramine.

The acylating agent which is reacted with the polyamine is an acyclic hydrocarbyl-substituted succinic acylating agent in which the substituent contains an average of 50 to 100 (preferably 64 to 80) carbon ioms. In order to accomplish the objectives of this invention, it is important that thtv cyclic hydrocarbyl S: substituted snccinic acylating agent have an acid number in the range of 0.7 to 11 (preferably in the range of 0.8 to 1.0, and most preftrably 0.3).

25 To achieve the objectives of tfis invention, the m.)91'r ratio of acylating agent to polyamine in the reaction product of an (ii) is in the raage of 1.5:1 to 2.2:1, preferably from 1.7:1 to 1.9:1, and more preferably 1.8:1, The acid number of the acyclic hydrocarbyl substituted succinic acylating agent is determined in the customary way by titration and is reported in terms ,f mg of KOH per gram of product. It is to be noted that this Case EI-6371 -4determination is made on the overall acylating agent with any unreacted olefin polymer polyisobutene) present.

The substituent of the succinic acylating agent is preferably an alkyl or alkenyl group having the requisite number of carbon atoms as specified above. Alkenyl substituents derived from poly-a-olefin homopolymers or copolymers of appropriate molecular weight propene homopolymers, butene homopolymers, C 3 and C 4 a-olefin copolymers, and the like) are suitable. Most preferably, the substituent is a polyisobutenyl group formed from polyisobutene having a number average molecular weight (as determined by gel permeation chromatography) in the range of 700 to 1200, preferably 900 to 1100, most preferably 940 to 1000.

Substituted succinic acid acylating agents and methods for their preparation and use in the formation of succinimide are well known to those skilled in the art and are extensively reported in the patent 15 literature. See for example the following U. S. Patents.

3,018,247 3,231,587 3,399,141 3,018,250 3,272,746 3,401,118 3,018,291 3,287,271 3,513,093 3,172,892 3,311,558 3,576,743 3,184,474 3,331,776 3,578,422 3,185,704 3,341,542 3,658,494 3,194,812 3,346,354 3,658,495 a. 3,194,814 3,347,645 3,912,764 3,202,678 3,361,673 4,110,349 25 3,215,707 3,373,111 4,234,435 3,219,666 3,381,022 When utilizing the general procedures such as described in these patents, the important considerations insofar as the present invention is concerned, are to insure that the substituent of tha acylating agent contain the requisite number of carbon atoms, that the acylating agent have the requisite acid number, that the acylating agent be reacted with the requisite polyethylene polyamine, and that the reactants be employed ;n proportions such that the resultant succinimide Scontains the requisite proportions of the chemically combined reactants, all as speci- "I Case EI-6371 fled herein. When utilizing this combination of featu,-, detergent/dispersants are formed which possess exceptional effectiveness in controlling or reducing the amount of induction system deposits formed during engine operation.

As pointed out in the above listed patents, the substituted succinic acylating agents include the substi-ted succinic acids, the substituted succinic anhydrides, the substituted succinic acid halides (especially the acid fluorides and acid chlorides), and the esters of the substituted succinic acids and lower alcohols those containing up to 7 carbon atoms), that is, substituted compounds which can function as carboxylic acylating agents. Of these compounds, the hydrocarbylsubstituted succinic acids and the hydrocarbyl-substituted succinic anhydrides and mixtures of such acids and anhydrides are generally preferred, the hydrocarbylsubstituted succinic anhydrides being particularly preferred.

The acylating agent used in producing the deterg-nt/dispersants of this 15 invention is preferably made by reacting a polyolefin of appropriate molecular weight (with or without chlorine) with maleic anhydride. However, similar carboxylic reactants can be employed such as maleic acid, fumaric acid, malic acid, tartaric d, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, mesaconic acid, ethyl-maleic anhydride, dimethylmaleic anhydride, ethylmaleic acid, dimethylmaleic acid, hexylmaleic acid, and the like, including the corresponding acid halides and lower aliphatic esters.

The reaction between components and (ii) is generally conducted at temperatures of 80*C to 200 C, more preferably 1400C to 180*C, such that :a succinimide is formed. These reactions may be conducted in the presence or 25 absence of an ancillary diluent or liquid reaction medium, such as a mineral lubricating oil solvent. Suitable solvent oils include natural and synthetic base oils having a volatility of less than 50% as determined by the test method described herein. The natural oils are typically mineral oils. Suitable synthetic diluents include polyesters, hydrogenated or unhydrogenated poly-a-olefins (PAO) such as hydrogenated or unhydrogenated 1-decene oligomer, and the like. Blends of S. mineral oil and synthetic oils are also suitable for this purpose. In a particularly preferred embodiment, the reactions are conducted in the substantial absence of F t Case EI-6371 -6 an ancillary diluent oil so that the reaction product is essentially free of paraffinic mineral oils. By essentially free is meant that the reaction product contains less than about 1% by weight paraffinic mineral oil.

As used herein, the term succinimide is meant to encompass the completed reaction product from components and (ii) and is intended to encompass compounds wherein the product may have amide, amidine, and/or salt linkages in addition to the imide linkage of the type that results from the reaction of a primary amino group and an anhydride moiety.

Mineral Oil. A key feature of this invention is the use of a mineral oil having a viscosity index of less than about 90 and a volatility of less than 50% as determined by the test method described herein as a diluent in the formation of the fuel additive concentrate or as a key component in blends of fuel mixtures and succinimide reaction product. The mineral oil more preferably has a volatility of

S

less than 45%. It has been found that when particular succinimide and particular mineral oil components are admixed with gasoline in particular proportions, deposits on internal engine parts are effectively controlled. By "effectively controlled" is meant, that the formation of such deposits is significantly inhibited, and/or engines initially containing heavy deposits, exhibit a substantial reduction in deposits when operated in accordance with the method of this invention.

20 Mineral oils having suitable volatilities include naphthenic and asDhaltic oils which are defined generally as those found along the Gulf Coast such as a S:i" Coastal Pale (commercially available from Exxon A typical Coastal Pale may contain 3-5 wt. polar material, 20-35 wt.% aromatic hydrocarbons, and 50-75 wt.% saturated hydrocarbons and have a molecular weight in the range of from 300 to 600. Asphaltic oils are defined as containing high molecular weight (ca 800) compounds with high polar functionality and little or no pure hydrocarbon type compounds. Principal polar functionalities generally present in such asphaltic oils include carboxylic acids, phenols, amides, carbazoles, and pyridine benzologs.

Typically, asphaltenes contain 40-50% by weight aromatic carbon and have molecular weights of several thousand. Asphaltic oils are generally found along the West Coast. Preferably the mineral oil has a viscosity at 100° F of less than 1600 SUS, more preferably less than 1500 SUS, and most preferably between 800 Case EI-6371 -7and 1500 SUS at 100" F. It is highly desirable that the mineral oil have a viscosity index of less than 90, more particularly, less than 70 and most preferably in the range of from 30 to 60. Suitable mineral oils may be selected from solvent extracted, hydrotreated, and non-hydrotreated mineral oils, however, the hydrotreated mineral oils are particularly desirable for use in the additive compositions of this invention.

The weight ratio of succinimide to the diluent oil in the mixtures of this invention is a particularly key feature of this invention. It has bere discovered that a weight ratio of less than 1 part succinimide to 4 parts mineral oil achieves the purposes of this invention. Preferably the weight ratio of succinimide to mineral 3, r.or- r tro oil is in the range of from 1 1.5 to 1 .a-and most preferably, the weight ratio is from 1 1.8 to 1 2.2.

Antioxidant. Various compounds known for use as oxidation inhibitors can be utilized in the practice of this invention. These include phenolic antioxidants, amine anti-oxidants, sulfurized phenolic compounds, and organic phosphites, among others. For best results, the antioxidant should be composed predominantly or 0 entirely of either a hindered phenol antioxidant such as 2-tert-butylphenol, 2,6-di-te. b tylphenol,2,4,6-tri-tert-butylphenol,4-inethyl-2,6-di-tert-butylphenol, 4,4'-methylenebis-(2,6-di-tert-u tylphenol), and mixed methylene bridged polyalkyl phenols, or an aromatic amine antioxidant such as the cycloalkyl-di-lower alkyl amines, and phenylenediamines, or a combination ot one or more such phenolic antioxidants with one or more such amine antioxidants.

Demulsifier. A wide variety of demusifiers are available for use in the practice of this invention, including, for example, organic sulfonates, polyoxyalkylene glycols, oxyalkylated phenolic resins, and like materials. Particularly pre-ferred are mixtures of alkylphenol or polyoxyalkylene glycols, and oxyalkylated alkylphenolic resins, such as are available commercially from Petrolite Corporation under the TOLAD trademark. One such proprietary product, identified as TOLAD 9308, is understood to be a mixture of these components dissolved in a solvent composed of heavy aromatic naphtha and isopropanol. This product has been found efficacious for use in the compositions of this invention. However, other i 1 ,A known demulsifiers can 'e used such as TOLAD 286.

Case EI-6371 Corrosion Inhibitor. Here again, a variety of materials are available for use as corrosion inhibitors in the practice of this invention. Thus, use can be made of dimer and trimer acids, such as are produced from tall oil fatty acids, oleic acid, linoleic acid, or the like. Products of this type are currently available from various commercial sources, such as, for example, the dimer and trimer acids sold under the HYSTRENE trademark by the Humko Chemical Division of Witco Chemical Corporation and under the EMPOL trademark by Emery Chemicals.

Another useful type of corrosion inhibitor for use in the practice of this invention are the alkenyl succinic acid and alkenyl succinic anhydride corrosion inhibitors such as, for example, tetrapro-penylsuccinic acid, tetrapropenylsuccinic anhydride, tetradecenylsucdinic acid, tetradecenylsuccinic anhydride, hexadecenyl-succinic acid, hexadecenylsuccinic anhydride, and the like. Also useful are the half esters of alkenyl succinic acids having 8 to 24 carbon atoms in the alkenyl group with alcohols such as the polyglycols. Preferred materials are the succinic acids or derivatives thereof represented by the formula: *R 3 CC 0 R

SR

6 C OR 4 C C OR R 2 wherein each of R 2

R

3

R

5 and R 6 is, independently, a hydrogen atom or a hydrocarbyl group containing 1 to 30 carbon atoms, and wherein each of R' and

R

4 is, independently, a hydrogen atom, a hydrocarbyl group containing 1 to carbon atoms, or an acyl group containing from 1 to 30 carbon atoms.

The groups R 2

R

3

R

4

R

5 and R' when in the form of hydrocarbyl groups, can be, for example, alkyl, cycloalkyl or aromatic containing groups.

Preferably RI, R 2 R, R R and R 5 are hydrogen or the same or different straightchain or branched-chain hydrocarbon radicals containing 1-20 carl:on atoms. Most Case EI-6371 -9 preferably, R 2

R

3

R

4 and R 5 are hydrogen atoms. R 6 when in the form of a hydrocarbyl group is preferably a straight-chain or branched-chain saturated hydrocarbon radical.

Most preferred is an alkenyl succinic acid of the above formula wherein

R

2

R

4 and R 5 are hydrogen and R is a totrapropenyl group.

Aromatic Hydrocarbon Solvent A wide variety of aromatic hydrocarbon solvents can be used with this invention such as benzene, and alkyl substituted benzene or mixtures thereof. Particularly useful are mixtures of and mxylenes, mesitylene, and higher boiling aromatics such as Aromatic 150 which is available from Chemtech. However, other mixtures of aromatic hydrocarbon solvents may also be used.

The relative proportions of the various ingredients used in the additive S:concentrates and fue!r of this invention can be varied within reasonable limits.

However, for best results, these compositions should contain from 10 to 50 parts by weight (prefably from 0 to 35 ps by weiht) of succinimide, p to 75 parts 1 by weight (preferably from 20 to 35 parts by weight) of diluent oimide, u to 5 parts by weight (preferably from 50 to 65 parts by weight) of diluent oil, 0 to 5 parts by weight (preferably, from 1 to 3 parts by weight) of antioxidint, from 0 to Sparts by weight (preferably, from 0.3 to 3 parts by weight) of demulsifier, from 0 *to 75 part, by weight (preferably 5 to 25 parts by weight) of aromatic hydro-carbon 20 solvent, and from 0 to 5 parts by weight (preferably, from 0.025 to 1.0 parts by weight) of corrosion inhibitor per each one hundred parts by weight of fuel additive composition.

i The above additive compositions of this invention are preferably employed in hydrocarbon mixtures in the gasoline boiling range or hydrocarbon/ oxygenate mixtures, or oxygenates, but are also suitable for use in middle distillate fuels, notably, diesel fuels and fuels for gas turbine engines. The nature of such fuels is so well known to those skilled in the art as to require no further comment.

By oxygenates is meant alkanols and ethers such as methanol, ethanol, prnpanol, methyl-tert-butyl ether, ethyl-tert-butyl ether, tert-amyl-methyl ether and the like.

It will of course be understood that the base fuels may contain other commonly used ingredients such as cold starting aids, dyes, metal deactivators, octane improvers, cetane improvers, emission control additives, antioxidants, and the like.

Case EI-6371 When formulating the fuel compositions of this invention, the additives are employed in amounts sufficient to reduce or inhibit induction system deposits in an internal combustion, engine. Generally speaking, the fuel additive comprising a succinimide and a mineral oil having a viscosity index of less than about 90 and a volatility of about less than 50% will be employed in unleaded gasoline in minor amounts such that the gasoline portion of the fuel is the major component. By minor amount is meant less than 1500 parts per million parts of gasoline, preferably, less than 1200 parts per million parts of gasoline. A particularly preferred amount of additive is in the range of from 500 to 1000 parts per million parts of gasoline.

The other components which are preferably used in conjunction with the detergent/ dispersant and mineral oil can be blended into the fuel individually or in various subcombinations. However, it is definitely preferable to blend all of the components concurrently using an additive concentrate of this invention as this takes advantage of the mutual compatibility afforded by the combination of ir.gredients when in the form of an additive concentrate, It is to be understood that the additive concentrate of this invention may be further diluted to improve the handling of the additive composition in the field.

*.V

The following Examples in which all parts are by weight illustrate, but are not intended to limit, this invention.

Example I A fuel additive concentrate is prepared from the following ingredients: 30 p rts of a detergent/dispersant formed by reacting polyisobutenylsuccinic anhydride having an acid number of 1.1 (made by reaction c' maleic anhydride and polyisobutene having a number average moleculai weight of 950) with a commercial mixture approximating triethylene tetramine, in a mole ratio of 1.8 1 repectively.

60 parts of naphthenic mineral oil of Witco Corporation 4053-Heavy.

2.8 parts of a tertiary butylated phenol antioxidant mixture containing a minimum of 75 percent of 2,6-di-tert-butylphenol, 10-15 percent of 2,4,6-tri-tert-butylphenol, and 15-10 percent of 2-tert-butylphenol.

Case EI-6371 11 1.5 parts of a demulsifier mixture composed of alkylaryl sulfonates, polyoxyalkylene glycols and oxyalkylated alkylphenolic resins in alkylbenzenes (TOLAD 286).

f parts of an aromatic solvent with a boiling range of 196-256 "C and a viscosity of 1.7 cSt at 25 o C.

0.5 parts of tetrapropenyl succinic acid, supplied as a 50% solution in light mineral oil.

This concentrate is blended with gasoline at concentrations of 150 pounds per thousand barrels (PTB).

10 Example 2 Example 1 is repeated using each of the components set forth therein except that 180 pounds per thousand barrels (PTB) of the concentrate additive °oS is formulated with gasoline.

Example 3 15 Example 1 is repeated using each of the components set forth therein except that 225 pounds per thousand barrels (PTB) of the concentrate additive is used in the gasoline mixture.

The effectiveness of the compositions of this invention in reducing induction system deposits was demonstrated in a series of standard engine tests 20 using the test gasoline formulation as in Examples 1, 2 and 3.

Example 4 In one set of tests the Briggs and Stratton engine test the formulation of Example 1 was compared to an untreated gasoline. The test utilized a Briggs Stratton 3 Hp engine with SAE 10W-40 oil. The length of the test was 150 hours. After breaking the engine in at varying speeds and loads the engine was then run at 3,000 RPM with a load of 500 Watts/0.67 Hp. The spark plug temperature was maintained at a':,ut 400° F. Oil level was checked often and the oil was changed after 80 hours. Valves were checked often and the oil was changed after 80 hours. Valves were weighed before and after the test to determine the Case EI-6371 12amount of deposits. Using Phillips J unleaded, untreated fuel, the amount of intake valve deposits was 413 mg. With the treated fuel of Example 1 under the same test conditions, the amount of intake valve deposits was 12 mg.

Example In another test using a 2.3L, 4 cylinder Ford engine and Midcontinenj Unleaded base fuel, a test gasoline as in Example 2 was compared to an untreated fuel. Duration of the test was 112 hours. The engine was prepared by cycling at 2,000 RPM with 0-4 BHP for 1 minute then 2,800 RPM at 37 BHP for 3 minutes.

The oil was checked every 8 hours and was changed at 56 hours. At the end of the testing period the intake valves and ports were removed and weighed. With the untreated fuel, the amount of intake valve deposits was 555 mg. Using treated fuel of Example 2, under the same test conditions, the amount of intake valve deposits was 28 mg.

9 Example 6 15 In yet another test, a BNV'W 318 with automatic trans-mission, 1.8L PFI engine was run on untreated and treated fuel using an East Coast regular unleaded gasoline. The engine was run for 10,000 miles. During the testing, the BMW was operated 10% at city speeds in stop and go traffic, 20% at moderate speeds with infrequent stops, and 70% at highway speeds of 65 MPH. To accumulate the 20 required mileage, the BMW was operated for 10 hours a day 800 miles per day.

The oil was changed according the BMW maintenance schedule. The intake valves were removed and weighed after 5,000 and 10,000 miles. Using mne untreated fuel, after 5,000 miles, the amount of deposits on the intake valves was 343 mg.

With the treated fuel of Example 3, after 5,000 miles the amount of intake valve deposits was 20 mg, and after 10,000 miles, the amount of intake valve deposits was 24 mg.

Example 7 In another series of tests, a Briggs Stratton engine was used to determine, on a pass or fail basis, which mineral oils would provide a low amount Case EI-6371 13 of valve deposits at treat rates of detergent/dispersant ranging from 30 to 40 (PTB) and mineral oil components ranging from 00 to 100 (PTB).

VISCOSITY VOLATILITY RESULTS MINERAL OIL INDEX LOST) (PASS/FAIL) B.P. SEB-78 95 21 Pass Witco 4053-13 44 49 Pass Sun Oil 500-SN 11 68 Fail Witco 4058-ML 46 44 Pass Arco 2950 97 >50 Fail Chevron 500-SN 104 28 Pass Shell HVI-600 91 25 Pass Witco 4053-Heavy 41 30 Pass Texaco ISO-46 101 66 Fail Exxon 325 98 46 Pass Shell HVI-250 90 >52 Fail Union Oil 450-N 82 42 Fail Exxon 900-SE 74 25 Pass Mineral Oil Volatility 20 To determine the volatility of the mineral oils suitable for use with this invention, the following procedure is used. Mineral oil (110-135 grams) is placed ina three-neck, 250 mL round-bottomed flask having a threaded port for a thermometer. Such a flask is available from Ace Glass (Catalog No. 6954-72 with 20/40 fittings). Through the center nozzle of the flask is inserted a stirrer rod having a Teflon blade, 19 mm wide x 60 mm long (Ace Glass catalog No. 8085-07). The mineral oil is heated in an oil bath to 300°C for 1 hour while stirring the oil in the flask at a rate of 150 rpm. During the heating and stirring, the free space above the oil in the flask is swept with 7.5 L/hr of inert gas nitrogen, argon). The volatility of the oil thus determined is expressed in terms of less than 13a Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

*e S* 0 S. 0* o 941222,p:\opcr\tb,23525,spe, 13

Claims (4)

14- THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS: 1. A motor fuel containing a major amount of unleaded gasoline and a deposit controlling amount of up to 1500 parts per million parts of the fuel of a combination of: a) 1 part by weight of the reaction product of alkylene polyamine and (ii) at least one substituted succinic acylating agent wherein the molar ratio of the acylating agent to polyamine in the reaction product is in the range of 1.5:1 to 2.2:1, and wherein the substituent is derived from polyisobutene having a number average molecular weight as determined by gel permeation chromatography in the range of 700 to 1200; and b) from 1.5 up to 4 parts by weight of a mineral oil having a viscosity index of less than 90 and a volatility of less than 50% as determined by a method described herein. 2. A motor fuel according to Claim 1 further comprising an effective amount of c) at least one antioxidant, or d) at least one demulsifier, or e) at least one corrosion :inhibitor, or a combination of any two or all three of d) and e). 3. A motor fuel according to Claim 2 wherein a combination of all three of d) and e) is present in said fuel. 4. A motor fuel according to any one of Claims 1 to 3 wherein per part by weight of a) there are from 1.5 up to 3 parts by weight of b). o S: 25 5. A motor fuel according to Claim 4 wherein the weight ratio of a) to b) S* is in the range of from 1:1.5 to 1:2.5. 6. A motor fuel according to Claim 4 wherein the weight ratio of a) to b) is in the range of from 1:1.8 to 1:2.2. 7. A motor fuel according to any one of the preceding claims wherein the "eight ratio of to (ii) is in the range of 1:1.8 to 1:2.2 and wherein the said substituent 941222,p\oper'dab,2352S.sp14 15 is derived from polyisobutene having a number average molecular weight as determined by gel permeation chromatography in the range of 900 to 1100. 8. A motor fuel according to any one of the preceding claims wherein the alkylene polyamine of a) is triethylene tetramine or a combination of ethylene polyamines which approximate triethylene tetramine, and wherein the fuel contains in the range of 500 to 1500 parts per million of the combination a) and b). 9. A method for controlling deposits which may develop on internal parts of a gasoline engine comprising providing for use as a gasoline engine fuel, a composition comprising a major amount of unleaded gasoline and a deposit controlling amount of up to 1500 parts per million parts of the fuel of a combination of: a) 1 part by weight of the reaction product of alkylene polyamine and (ii) at least one substituted succinic acylating agent wherein the molar ratio of the acylating agent to polyamine in the reaction product is in the range of 1.5:1 to 2.2:1, and wherein the substituent is derived from polyisobutene having a number average molecular weight as determined by gel permeation chromatography in the range of 700 to 1200; and b) from 1.5 up to 4 parts by weight of a mineral oil having a viscosity index of less than 90 and a volatility of less than 50% as determined by a method described herein. 10. The method of Claim 9 wherein the weight ratio of to (ii) is in the range of from 1:1.8 to 1:2.2. 25 11. The method of Claim 9 or Claim 10 wherein the polyamine is triethylene tetramine or a combination of ethylene polyamines which approximate triethylene tetramine. 12. The method of any one of Claims 9 to 11 wherein the deposit control mixture further comprises a) an antioxidant; b) a demulsifier; 941222,p:\oper~dab,23525.sp,

16- c) a corrosion inhibitor; d) an aromatic hydrocarbon solvent; or e) any combination of any two or three or all four of components and wherein the weight ratio of the reaction product of polyarine and at least one substituted succinic acylating agent, to the mineral oil is in the range of from 1:1.8 to 1:2.2 and wherein the molar ratio of acylating agent to polyamine is 1.8:1. 13. A metal-free fuel additive concentrate which comprises per each 100 parts by weight thereof: a) from 10 to 50 parts by weight of the reaction product of alkylene polyamine and (ii) at least one substituted succinic acylating agent wherein the molar ratio of the acylating agent to polyamine in the reaction product is in the range of 1.5:1 to 2.2:1, and wherein the substituent is derived from polysiobutene having a number average molecular weight as determined by gel permeation chromatography in the range of 700 to 1200; th b) up to 75 parts by weight of a mineral oil having a viscosity index of less than 90 and a volatility of less than 50% as determined by a method described herein; c) 0 to 5 parts by weight of antioxidant; d) 0 to 10 parts by weight of demulsifier; e) 0 to 75 parts by weight of aromatic hydrocarbon solvent; and Sh.. f) 0 to 5 parts by weight of corrosion inhibitor; the weight ratio of b) to a) corresponding to from 1.5 up to 4 parts by weight of b) per part by weight of a). 25 14. A fuel additive concentrate according to Claim 13 wherein per each 100 ".*parts by weight thereof, there are from 20 to 35 parts by weight of from 50 to parts by weight of from 1 to 3 parts by weight of from 0.3 to 3 parts by weight of from 5 to 25 parts by weight of and from 0.025 to 1.0 part by weight of f). c 941222,p:\oeidab,23S25.spe,16

17- A fuel additive concentrate according to Claim 13 or Claim 14 wherein the weight ratio of a) to b) is in the range of 1:1.5 to 1:2.5. 16. A fuel additive concentrate according to any one of Claims 13 to wherein the weight ratio of a) to b) is in the range of from 1:1.8 to 1:2.2. 17. A fuel additive concentrate according to any one of Claims 13 to 16 wherein the alkylene polyamine is triethylene tetramine or a combination of ethylene polyamines which approximate triethylene tetramine, wherein the said substituent is derived from polyisobutene having a number average molecular weight as determined by gel permeation chromatography in the range of 900 to 1100, and wherein the weight weight ratio of to (ii) is in the range of 1:1.8 to 1:2.2.

18. Fuel additive concentrates, or fuels or methods involving them, substantially as hereinbefore described with reference to the Examples. 9* DATED this 22nd day of December, 1994 *Ethyl Petroleum Additives, Inc. By Its Patent Attorneys 25 DAVIES COLLISON CAVE *9 **n DATED this 22nd day of December, 1994 Ethyl Petroleum Additives, Inc. By Its Patent Attorneys 25 DAVIES COLLISON CAVE g 1 941222,p:('peiab,23525.sp.17