CA2054493A1

CA2054493A1 - Motor fuel composition having enhanced water tolerance

Info

Publication number: CA2054493A1
Application number: CA 2054493
Authority: CA
Inventors: Samir Samaan Ashrawi
Original assignee: Texaco Chemical Co
Current assignee: Texaco Development Corp
Priority date: 1991-03-18
Filing date: 1991-10-29
Publication date: 1992-09-19
Also published as: JPH05105888A; DE69202293D1; DE69202293T2; EP0505070A1; EP0505070B1

Abstract

MOTOR FUEL COMPOSITION
HAVING ENHANCED WATER TOLERANCE

(D#80,992 -F) ABSTRACT OF THE DISCLOSURE

A motor fuel composition comprising a base fuel and: (I) the reaction product of (a) a hydrocarbyl-substituted dibasic acid anhydride and (b) a polyoxyalkylene diamine; (II) a polymeric component which is a polyolefin polymer/copolymer or the corresponding aminated or hydrogenated polymer/copolymer, or mixtures thereof; (III) a polyalkylene glycol having a molecular weight in the range of 500-2000; (IV) a lubricating oil composition, and (V) a polyoxyalkylene adduct of a linear or branched aliphatic alcohol, or an alkyl phenol. The adduct is employed as a surfactant additive and in an amount sufficient to enhance the water tolerance of the motor fuel composition.

80992ps.dgv

Description

MOTOR FUEL COMPOSITION
HAVING ENHANCED WATER TOLERA~CE

(D#80,992 -F) BACXGROUND OF THE INVENTION

1. Field of the Inyen~Q~

This invention relates generally to a motor fuel composition and, more particularly, to a motor fuel composition having enhanced water tolerance which is ascribed to the presence of a surfactant additive.

2. Descriptio~ of Backqround Art It is well known that water and moisture can be present in motor fuel compositions, especially under field storage conditions. ~ypically, the water and motor fuel exist as water-in-petroleum macroemulsions, that i6, the water becomes 2S trapped in the petroleum ~ubstrate. The shortcomings associated with the presence of water in motor fuels are numerous. In particular, unsta~le hazy blends can result when water is present as macroemulsions in such sy~tems. Hazy motor fuel blends are unacceptable by the public, since they are typlcally perceived as being contaminated and, hence, unable to perform at a satisfactory level. Also, macroemulsions can cause the motor fuel to become too vi~cous, ma~ing it difficult to filter, and can clog fuel filters. Furtbermore, where excess water i~ being pumped through gas lines, an in~dequate combustion can result. Corrosion i~ also a pro~lem ascribed to the presence of water in motor fuel composit~ons.

205449:~
In addition to the foregoing shortcomings, if water dissipates out at the bottom ~f the macroemulsion as a separate layer, some of the motor fuel additives may partition into that water phase, thereby depriving the fuel of the full intended benefit of these additives. Also, by driving some of the motor fuel into the excess water phase, this partitioning may cause the formation o~ undesirable macroemulsions with a milky appearance in that phase. ~his situation could occur in surface ~torage facilities and underground storage tanks at gasoline atations, due to rain conditions and/or improper maintenance of these tanks. Presumably, some emulsion may be pumped into ~n automobile gasoline tank, resulting in automobile operability problems, and, accordingly, customer dissatisfaction.
In contrast, if it were possible to retain water in the motor fuel composition as a microemulsion, a significant contribution would be made to the art, inasmuch as micro-emulsions are optically clear, thermodynamically stable and retain the viscosity of their continuous phase.

In the past, attempts have been made to improve the water-tolerance of certain fuels. For instance, U.S. Patent No.
4,808,195 describes a chemical mixture for use as an additive 2S in liquid hydrocarbon fuel and/or water. In particular, the mixture includes a chemical compound having hydrophilic gualities selected from the group consi~ting of ethylene glycol, n-butyl alcohol, ether and cellosolve ~methyl ether of ethylene glycol); ethoxylated nonylphenol; nonylphenol polyethylene glycol ether and, optionally, methanol.

U.S. Patent No. 4,599,088 descri~es a clear ~ta~le gasoline-alcohol-water ~otor fuel composition which incl~des certain alcohols; about 0.10 to 0.~0 weight percent water;

1101192p- . d6v -- 2 about 0.10 to 3.0 weight percent of a nonionic adduct of alkylphenol and ethylene oxide surfactant having 9 to 24 carbon atoms in the alkyl group and 6 to 10.0 ethylene oxide groups;
and gasoline.

U.S. Patent No. 4,568,354 describes a process for converting hazy gasoline to clear stable gasoline by adding a nonionic ~urfactant of an aminated polyisopropoxylated polyethoxylated alkylphenol to the hazy gasoline.
U.S. Patent No. 4,410,334 describes a hydrocarbon fuel composition which includes, inter alia, a polyether in an amount sufficient to provide a desired level of water tolerance. Ethoxylated alkylphenols are contemplated as one type of polyether which may be used.

U.S. Patent No. 4,158,551 describes a gasoline-water emulsion which is formed by mixing gasoline, water and a nonionic ethoxylated alkenylphenol surfactant.
U.S. Patent No. 3,876,391 describes a process for preparing microemulsions. In their process, patentees employ at least one water soluble surfactant. A nonylphenol ethoxylated surfactant is employed in Example I.
Other patents of interest include U.S. Patent Nos.
4,609,377; 4,568,480; 4,549,884; 4,116,644; 4,046,519;

3,752,6S7; and 3,527,581. Finally, Shinoda et al., Conditions to Produce So-c~lled Microemulsions: Factors to Increase the Mutual solubility of Oil and Water by Solubilizer, Journal of Co}loid and Interface Science, Vol. 42, No. 2, pp. 3~1-3~7 (February 1973), is also cited for background interest.

U.S. Patent No. 4,~68,32~ describes an ORI-inhibited motor 11093Zp~ . dSv _ 3 fuel composition which comprises a base fuel and ~I) the reaction product of (a) a hydrocarbyl-substituted dibasic acid anhydride and (b) a polyoxyalkylene diamine; (II) a polymeric component which is a polyolefin polymer/copolymer or the corresponding aminated or hydrogenated polymer/copolymer, or mixtures thereof, of a C2-C10 hydrocarbon; (III) a polyalkylene glycol having a molecular weight in the range of 500-2000; and (IV) a lubricating oil composition. U.S. Patent No. 4,968,321 is incorporated herein by reference.
Accordingly, it is my understanding that the water tolerant motor fuel composition described and claimed hereinbelow has heretofore been unknown.

SUMMARY OF THE INVENTI~N

The motor fuel composition of the present invention comprises a mixture of hydrocarbons boiling in the range of from about 90F to about 450F and (I) the reaction product of (a) a hydrocarbyl-substituted dibasic acid anhydride and (b) a polyoxyalkylene diamine; (II) a polymeric component including a polyolefin polymer, a polyolefin copolymer, an aminated polyolefin polymer, an aminated polyolefin copolymer, a halogenated polyolefin polymer, a halogenated polyolefin copolymer or mixtures thereof; (III) a polyoxyalkylene glycol having a molecular weight in the range of about 500 to about 2000; (IV) a lubricating oil; and (V) a polyoxyalkylene adduct of a linear or branched aliphatic alcohol, or an alkyl phenol, said adduct being employed ac a surfactant additive and in an amount sufficient to enhance the water tolerance of said motor ~uel composition.

~t has advantageously been discovered t~at the present motor fuel composition retains more water i~ the microemu1sion 80Ç1~2p- . d6`' phase as opposed to the unstable, visco~s and opaque macro-e~ulsion phase. As a result, the motor fuel composition of the present invention overcomes those problems identified above which are characteristic of the prior art motor fuel compositions.

It is further believed that the motor fuel composition described herein exhibits unexpected levels of water tolerance relative to similar compositions which are known.
The present motor fuel composition is expected to exhibit its enhanced tolerance to water under field storage conditions in both sur~ace and underground tanks and in automobile gas tanks.
DESCRIPTION OF THE PREFERRED EMBODIMENTS

The hydrocarbyl-substituted dibasic acid anhydride reactant used to prepare the reaction product component (I) of the instant invention may be represented by the formula:

f (f~2)y o O
where Rl is a hydrocarbyl group having a molecular weight range of about 500-10,000, preferably about 500-2500, more pre~erably about 600-1500, and ~ost preferably about 1290, and y has a value of 0-3. In a preferred embodiment, R1 is a polypropenyl or polybutenyl group. Nost preferably, Rl is a polyisobutenyl group. Where Rl is the preferred po~yisobutenyl group, y 110~12p~ . d6v -- 5 preferably has a value of 0, and the preferred hydrocarbyl-substituted dibasic anhydride reactant for use is a polyisobutenyl succinic acid anhydride of the formula:
f fH3 11 CH3 ~ F - tCH2 ~ T~ x CH = T - CH2 - TH c CH3 CH3 CH3 CH2 f O

where x has a value of about 10-25, preferably 20-25. This polyisobutenyl succinic acid anhydride is m~st preferably formed by reacting maleic anhydride an~ a polybutene, such as a polybutene commercially available from Amoco Chemical Company under the INDOPOL series trade name, the most preferred polybutene reactant beinq commercially available as INDOPOL H-300. Methods of formulating the above described polyisobutenyl succinic acid anhydride reactant are disclosed in, inter alia, U.S. Patent Nos. 4,496,746, 4,431,825, 4,414,397, and 4,325,876, all incorporated herein by reference.

The polyoxyalkylene diamine reactant used to prepare the reaction product component (I) of the instant invention is a diamine of the formula:

ICH2CH3 fH2CH3 NH2 ~ R2 ) q 1 OCHCH2 1 a ~ ICHCH2 ] b- ~ 0CH2CH2 1 c~ ~ 0CH2 ICH 1 d- ~ 0CH2CH 1 e~ ( R3 ) r~NH2 where ~2 and R3 are Cl-C12 alkylene groups, q and r are ~ntegers havin~ a value of about 0-1, c has a value of from about 2-S50, preferably about 2-50; b+d has a value of from a~out 2-150, 1106Upo . dl~ ,r -- 6 preferably about 2-50; and a+e has a value of about 2-12, preferably about 2-8.

In another preferred e~.bodiment, q=1, r=O, R2 is a propylene group, a+e has a value of zero, and the polyoxyalkylene diamine reactant is of the formula:

NH2-~HCH2-tO ~cH2~b-[ocH2cH2]c-tocH2fH]d-NH2 C~3 CH3 CH3 where c and b+d, respectively, have a ~alue of from about 2-150, preferably about 2-50. As merely illustrative, polyoxyalkylene diamines of the above structure suitable for use include those available from Texaco Chemical Company under the JEFFAMINE~ ED-Series trade name. Specific examples of such compounds are set forth below:

A~Drox. Value Approx.
Trade Name c bldMol. Wt.
ED-600 8.5 2.5 600 ED-900 15.5 2.5 900 ED-2001 40.5 2.5 2000 ED-4000 86.0 2.5 4000 ED-6000 131.~ 2.5 6000 The polymeric component (II) of the motor fuel composition of the present invention is generally described as a polyolefin polymer, copolymer, or corresponding aminated or hydrogenated polymer or copolymer, or mixture~ thereof, of a C2-ClO
hydrocarbon. Accordingly, as used in this description and in the claims which follow, the phrase "polymers" is intended to include the polyolefin p~lymers and their corresponding hydrogenated or aminated derivatives. The polymeric component eoa~2p.d6v _ 7 _ (II) is usually employed in admixture with a hydrocarbon solvent to facilitate its addition into a base motor fuel composition.

In one preferred embodiment of the instant invention, the polymeric component is polypropylene with an average molecular weight of about 750-1000, preferably about 800. In another preferred embodiment, the polymeric component is polyiso-butylene with an average molecular weight of about 100-1500, 10 . preferably about 1300. In yet another preferred embodiment of this invention, the polymeric component is a mixture of a major amount of polyisobutylene ethylene diamine and a minor amount of polyisobutylene in admixture with a suitable amount of hydrocarbon solvent. In this embodiment, the polyisobutylene ethylene diamine sub-component of the polymeric component is typically present in a concentration range of about 50-75 parts, preferably about 60 parts by weight, based upon the we~ght of the entire composition which makes up the polymeric component. The polyisobutylene ethylene diamine sub-component is of the formula:

CH3 IC ~cH2-~]z-cH=f-cH2-NH-cH2-cH2-NH2 where z has a value of about ~0-40, preferably about 30-35.
The polyisobutylene sub-component of the polymeric component i6 typically present in a concentration range of about 5-25 parts, preferably about 10-20 parts by weight, based upon the weight of the entire composition which makes up the 3~ polymeric component. The polyisobutylene sub-componen' is of the formula:

00992p~. d~v -- ~ --2054A9:~
fH3 fH3 /CH3 CH3~f~~CH2~f]z~CH=C

where z again has a value of about 10-40, preferably 30-35.

The hydrocarbon solvent employed to facilitate admixture o~ the polymeric component into a base motor fuel composition is preferably a light aromatic distillate composition. A
commercially available light aromatic distillate composition containing the above described polyisobutylene ethylene diamine and polyisobutylene compounds in the above specified concentrations and, therefore, most preferred for use as the polymeric component of the instant invention, is the commercial gasoline additive ORONITE OGA-472, available $rom Chevron Chemical Company. ORONITE OGA-472 is a composition containing approximately 60 parts by weight of polyisobutylene ethylene diamine, approximately 13 parts by weight of polyiso~utylene, and approximately 27 parts by weight of light aromatic di~tillate, including xylene and C9 alXylbenzenes. Fuel compositions containing ORONITE OGA-472 as an additive include those described in U.S. Patent Nos. 4,141,693, 4,028,065, and 3,966,429.

The polyoxyalkylene glycol component (III) of the motor fuel composition of the instant invention has a molecular weight in the range of a~out 500-2000, preferably about 750-1000. The polyoxyalkylene glycol component is preferably selected 2rom the group consi~ting of polyethylene glycol, polypropylene glycol; and polybutylene glycol, and $B most prefera~ly a polypropylene glycol having a molecular weight ~n the range of about 750-1000.

00992p~,d6v _ 9 _ Z0544g3 The lubricating oil component (IV) of the motor fuel composition of the instant invention may be a natural, synthetic or heavy oil. Suitable lubricating oils for use in the motor fuel composition of the instant invention are described, for example, at columns 29-30 of V.S. Patent No.
4,670,173, incorporated herein by reference, and include, in one preferred embodiment, natural oils, such as animal oils, vegetable oils, mineral lubricating oils (e.g., liquid petroleum oils, solvent-treated and acid-treated mineral oils of paraffinic, naphthenic, and mixed paraffinic-naphthenic types), and lubricating oils derived from shale or coal.

In another preferred embodiment, the lubricating oils employed is a synthetic lubricating oil. Synthetic oils suitable for use include hydrocarbon oils, halo-substituted hydrocarbon oils, such as polymerized and interpolymerized olefins, oligo-alkenes, alkylbenzenes, polyphenyls, alkylated diphenyl ethers and sulfides, and substituted and unsubstituted polyalkylenes and alkylene oxide polymers and copolymers (e.g., oils prepared through polymerization of ethylene oxide or propylene oxide, the alkyl and aryl ethers of these polyoxyalkylene polymers, or mono- and polycarboxylic esters thereof, such as acetic acid or fatty acid esters).
Polyalkylene lubricating oil compositions having a molecular 2S weight in the range of about 500-2000, preferably about 800-1400, are preferred for use as the lubricating oil component, with polypropylene having a molecular weight in the range of about 800-1400 and polyisobutylene having a molecular weight in the range of about 800-1000 being particularly preferred.
Yet another par~icularly preferred class of oils for use as the lubricating oil component are unrefined or refined heavy oils. Unrefined oils are those obtained directly from a natural or synthetic s~urce without further purification ~0992p- . d~,v -- 10 zo~4*93 treatment. Refined oils are similar to unrefined oils, except they have ~een further treated in one or more purification steps to improve one or more properties. Many such purification techniques (e.g., solvent extraction, secondary distillation, acid or base extraction, filtration, percolation) are well known to those skilled in the art. A particularly preferred class of heavy oils for use are known to those skilled in the art as paraffinic Solvent Neutral Oils (SNO).
An example of a paraffinic SNO for use as the lubricating oil component of the instant invention is SNO-600, which has a viscosity of about 20-60 cSt at 40C.

As stated above, the motor fuel composition of the present invention further includes a surfactant additive which is employed to enhance the water tolerance of the motor fuel composition. In particular, the surfactant additives are generally referred to as alkylphenol alkoxylates or alcohol alkoxylates, which may be used alone or in combination.
Similarly, the surfactants are also referred to as polyoxy-alkylene alkylphenols or alcohols. More specifically, they are, in one aspect, polyoxyalkylene adducts of alkylphenols and, in another aspect, polyoxyalXylene adducts of linear or branched aliphatic alcohols. Thus, the surfactants are derived from alkylphenols and linear or branched aliphatic alcohols which have been reacted with an alkylene oxide to various degrees of alkoxylation.

The surfactant additives used in the motor fuel composition of the present invention are represented by the general formula:
~2 Rl - O - (CH2CHO) X }~' 110~12p- . tS

Z05449~

where x is an integer from about 1 to about 10, Rl is either (a) Cn H2n+l, where n is an integer from 10 to 18, or (b) Cn H2n+1 - C6H4, where n is an integer from 8 to 18 and where R2 is H~, CH3- or CH3CH2-.

In the formula used to represent the preferred surractant additive, R2 ~8 H~ And, thus, the preferred surractant ~e~ in one aspect, a polyoxyethylene adduct of an alkylphenol and, in another a~pect, a polyoxyethylene adduct of linear or branched aliphatic alcohols.

More specifically, the preferred ethoxylated alkylphenol surfactants used herein are represented by the general formula:

CnH2n+1~ ~--0--(CH2CH20)X-H~

where n is an integer between about 8-18 and x i~ from about 1 to about 10. Particularly preferred ethoxylated alkylphenol ~urfactant~ are ~elected from nonylphenol ethoxylates in the HLB rango of about 3-11, that i~, with between 1 and 6 ethylene oxide units. SURFONIC N-40, an ethoxylated nonylphenol surfactant available from Texaco Chemical Company ~ repre-sentative of the preferred ~urfactant.

~he preferred ethoxylated alcohol surfactant_ used herein are represented by the general formula:

Cn H2n~,-0- (CH2CH20) x-~
I~D992p~ 12 --where n is an integer between about 8-18 and x is from about 1 to about 10.

An important criterion for characterizing the surfactant is the Hydrophile-Lipophile Balance (HLB). More specifically~
the HLB refers to the relative simultaneous attraction that the surfactant demonstrates for water and oil. Substances having a high HLB, above about 12, are highly hydrophilic (and poorly lipophilic) while substances having a low HLB, below about 8, are lipophilic and consequently poorly hydrophilic. Those having an HLB between about 8 and 12 are intermediate. An extensive discussion of HLB can be found in the literature particularly in "Emulsions: Theory and Practice," by P. Becher, published by Reinhold Publishing Corp., N.Y., l9S7. The HLB
for the surfactants used herein, is in the range of about 3 to about 11. More preferably, the HLB of the surfactants is from about S to about 10. Surfactants having an HL~ within the preferred range advantageously exhibit a greater affinity or solubility in oil than in water.
The motor fuel composition of the instant invention comprises a major amount of a base motor fuel and: (I) from about 0.0005 to about 5.0 weight percent, preferably 0.001-~.0 weight percent of the above described reaction product of (a) the hydrocarbyl-substituted dibasic acid anhydride, and (b) the polyoxyalkylene diamine; (II) from about 0.001 to about 1.0 weight percent, preferably 0.01-0.5 weight percent of the above described polymeric component; (III) from about 0.001 to about 1.0 weight percent, preferably 0.001-0.5 weight percent of the above described polyoxyalkylene glycol component; (IV) from about 0.00~ to about 1.0 weight percent, preferably 0.001-0.5 weight percent of the above described lubricating oil component; and (V) from about 0.001 to about 5.0 weight percent of the above described surfactant additive. Preferably, the ô0992p- . d~v -- 13 surfactant additive is employed in an amount of up to about 1.0 weight percent and, most preferably, is employed in an amount of about .5 weight percent.

Preferred base motor fuel compositions are those intended for use in spark ignition internal combustion engines. Such motor fuel compositions, generally referred to as gasoline base ~tocks, preferably comprise a mixture of hydrocarbons boiling in the gasoline boiling range, preferably from about 90F to about 450F. This base fuel may consist of straight chains or branched chains or paraffins, cycloparaffins~ olef~ns, aromatic hydrocarbons, or mixtures thereof. The base fuel can be derived fr~m, among others, straight run naphtha, polymer gas~line, natural gasoline, or from catalytically cracked or thermally cracked hydrocarbons and catalytically reformed stock. The composition and octane level of the base fuel are not critical and any conventional motor fuel base can be employed in the practice of this invention.

In the following examples, inventive and comparative motor fuel compositions were prepared to determine the extent of macroemulsion and microemulsion formation. ~he extent of macroemulsion formation was determined by visual inspection of the emulsion and by measuring the time it took to clear the gasoline and water phase. The extent of microemulsion formation was determined by the experimental approaches of water retention analysis and water uptake analysis.

More specifically, water uptake and water retention experiments are employed to quantify the amount of water that can be solubilized and, thus, tolerated, in a motor fuel composition. Advantaqeously, the two tec~niques approach the same equilibrium state from two d$rections. Accordingly, ~y employing these two analytic techniques, the results provided I~D992p~ v -- 1 4 below reflect a true thermodynamic equilibrium.

In the examples used to determine water uptake tExamples I-V and Comparative Examples VI-XV), water and gasoline were mixed at a water:gasoline ratio of 10:40 and at the varying temperatures identified in Table I and, thereafter, were permitted to equilibrate in a circulation bath and settle at the various temperatures, The resulting clear gasoline layers were tw~ce sampled and analyzed (two separate runs) for water content by the Karl Fischer titration method. In Examples I-V, each of the gasoline compositions included .5 weight percent of SURFONIC~ N-40. The gasoline compositions produced in Comparative Examples VI-XV did not include the surfactant additive. In Examples I-V and Comparative Examples VI-X, regular unleaded gasoline having the composition described in U.S. Patent No. 4,96~,321 was employed. In Examples XI-XV, an unrelated commercial brand of regular unleaded gasoline was employed.

8D9g2p- . d6v -- 15 EXAMPLES I-V AND COMPARATIVE EXAMPLES VI~V

TABLE I
S
Temp. Run Run (F~ No. 1 ~Q. 2 Averaae E~a~ple No.

Comparative Ex~mple No, VII o 133 136 135 - all values given are ppm, except when otherwise indicated.

As these data demonstrate, the inventive gasoline 35compositionfi produced in Examples I-V, which include the ~1 SURFONI ~ N-40 surfactant additive, exhibit an increased water r content o~ the microemulsion relative to the non-inventive ga~oline compositions produced in Comparat$ve Examples VI-X and the gasoline compositions produced in Comparative Examples XI-40XV, all of which are devoid of the surfactant add~tive.

In the examples used to determine water retent$on (Examples XVI-XX and Comparative Examples XXI-XXV), water and gasoline were mixed at a water:gasol$ne ratio of 10:40 at room 1~0992p~ 6 --temperature. The mixtures were then allowed to e~uilibrate and settle at room temperature. Thereafter, the water and gasoline layers were separated in a separatory funnel. The gasoline is presumed to contain the equilibrium amount of water at room temperature. The gasoline phase (layer) was then divided into five parts, each of which was cooled down to a different temperature listed in Table II. Two samples were drawn from each part (at different temperatures), and analyzed (two separate runs) for water content. This experiment allows one to determine if the water content drops or stays the same as the temperature is decreased.

The gasoline employed in the mixtures of Examples XVI-XX
was the same gasoline employed above in Examples I-V and Comparative Examples VI-X and that employed in Examples XXI-XXV
was another commercial brand of unleaded gasoline. The mixtures of Examples XVI-XX and Comparative Examples XXI-XXV
all included .5 percent by weight of SURFONIC~ N-40.

00992pa . d~v ~ 17 z~)~;449~
EXAMPLES XVI-XX AND CoMpARATIvE EXAMPLES XXI-XXV

TABLE II

Temp. Run Run (F) No. 1 No. 2 A~eFaae ExamDle No.

Comparative ~xample No.

XXII o 142 .166 154 As these data demonstrate, the water content of the gasoline composition formed in Examples XVI-XX retained more water in microemulsion form at all temperatures than did the non-inventive gasoline compositions formed in Examples XXI-XXV.
In the following Examples XXVI-XXXI, the water content of five (5) different gasoline/water admixture5 (Example XXVII was a straight gasoline sample) were determined by the Xarl Fisher titration method. In each of the examples ~except XXVII) water 35and gasoline were mixed and shaken at the water:gasoline ratios identified in Table III and at a temperature of 25C. The samples of Examples XXVII-XXXI contained .~ weight percent of SURFONIC~ N-40. Example XXVI did not contain any SURFONIC~ N-40. The Karl Fisher titrat~on re~ults are also reported in 40Table III. In Example XXVI and Examples XXVIII-XXXI, the resulting macroemulsions were obser~ed as they broke up, 110992p- . d6~ -- 18 leaving behind optically clear gasoline (water retained in microemulsion) and water layers. The gasoline layers were sampled twice (two runs) for water content analysis. The gasoline used in Examples XXVI-XXXI was, again, that described in U.S. Patent No. 4,968,321. The samples of Examples XXVI and XXVII represented baseline data, inasmuch as the gasoline in Example XXVI contained no added surfactant such as SURFONIC~ N-40, and in Example XXVII, the gasoline contained the added surfactant but was not brought in contact with water.
EXAMPLES XXVI-XXXI

TABL~ III
Water:GasolineWater Content (~Dm) Exam~le No.RatioRun No. 1 Run No. 2 Averaae XXVI 10:40 249 160 205 XXVIII 1:49 830 840 835 XXIX 5:45 1290 1190 1240 XXX 10:40 1390 1210 1300 XXXI 25:25 1150 907 1029 As these data demonstrate, when the surfactant of this invention is included with the additives described in U.S.
Patent No. 4,96~,321, the water content in the gasoline in microemulsion form is significantly increased at all the water-~o to-gasoline ratios that were investigated. Without the surfactant of this invention, Example XXVI shows that only a minor increase in the water tolerance of the gasoline is achieved.

In the following Examples XXXII-XXXVII, the water content of five ~5) additional gasoline/water admixtures (Examples XXXIII was a straight gasoline sample) were determined by the aoss2p-~dtY -- lg --Karl Fisher titration method. In each of the examples (except XXXIII) water and gasoline were mixed and shaken at the water:gasoline ratios identified in Table IV and at a temperature of 2SC. The samples of Examples XxxIII-xxxvII
each contained .5 weight percent of SURFONIC~ N-40- The sample of Example XXXII contained no added surfactant. The Karl Fisher titration results are also reported in Table IV. In Examples XXXIV-XXXVII, the resulting macroemulsions were observed as they broke up, leaving behind optically clear gasoline (water retained in microemulsion) and water layers.
The gasoline layers were sampled twice (two runs) for water content analysis.

~XAMPLES XXXII-XXXVII
TABLE IV
Water:Gasoline Water Content Lppm) _ Example No. Ratio Run No. 1 Run No. 2 Ave~aae XXXII 10:40 182 175 179 XXXIV 1:49 290 260 275 XXXV 5:45 250 290 270 XXXVI 10:40 290 265 278 XXXVII 25:25 340 2~0 310 As demonstrated by these data and those data presented ~oabove in Table III, the motor fuel composition of the present invention (Examples XXVIII-XXXI) retains a substantially greater amount of water in microemulsion form relative to the amount retained by non-inventive compositions (XXXIV-XXXVII).

35As evidenced by the data in Tables I-IV, the surfactant of this invention alone does not substantially increase the amount of water in microemulsion form in the gasoline. Analogous~y, 80092p- . ~6" -- 20 the motor fuel composition including the additives described in U.S. Patent No. 4,968,321 alone do not substantially increase the amount of water in microemulsion form in the gasoline.
However, when the surfactant of this invention is included in the gasoline composition described in U.S. Patent No.
4,968,321, a substantial increase in the water tolerance of the gasoline is obtained.

8Dfl92p- . dsv -- 21

Claims

1. A motor fuel composition comprising a mixture of hydrocarbons boiling in the range of from about 90°F to about 450°F and (I) the reaction product of (a) a hydrocarbyl-substituted dibasic acid anhydride and (b) a polyoxyalkylene diamine; (II) a polymeric component including a polyolefin polymer, a polymeric copolymer, an aminated polyolefin polymer, an aminated polyolefin copolymer, a halogenated polyolefin polymer, a halogenated polyolefin copolymer or mixtures thereof; (III) A polyoxyalkylene glycol having a molecular weight in the range of about 500 to about 2000; (IV) a lubricating oil; and (V) a polyoxyalkylene adduct of a linear of branched aliphatic alcohol, or an alkyl phenol, said adduct being employed as a surfactant additive and in an amount sufficient to enhance the water tolerance of said motor fuel composition.

2. The motor fuel composition of Claim 1 wherein said (v)polyoxyalkylene adduct is represented by the formula:

where x is an integer from about 1 to about 10, R1 is either (a) Cn H2n+1, where n is an integer from 10 to 18, or (b) Cn H2n+1 - C6H4, where n is an integer from 8 to 18 and where R2 is H?, CH3- or CH3CH2-.

3. The motor fuel composition of Claim 1 wherein said surfactant additive comprises an alkylphenol ethoxylate.

4. The motor fuel composition of Claim 1 wherein said surfactant additive comprises an alcohol ethoxylate.

5. The motor fuel composition of Claim 1 wherein said surfactant additive has a hydrophile-lipophile balance of about 3 to about 11.

6. The motor fuel composition of Claim 1 wherein said surfactant additive has a hydrophile-lipophile balance of about 5 to about 10.

7. The motor fuel composition of Claim 3 wherein said alkylphenol ethoxylate is represented by the formula:

where n is an integer between about 8-18 and x is an integer from about 1 to about 10.

8. The motor fuel composition of Claim 1 wherein said surfactant additive comprises a nonylphenol ethoxylate having a hydrophile-lipophile balance of about 3 to about 11.

9. The motor fuel composition of Claim 4 wherein said alcohol ethoxylate is represented by the formula:

Cn H2n+1-O-(CH2CH2O)x-H, where n is an integer between about 8-18 and x is an integer from about 1 to about 10.

10. The motor fuel composition of Claim 1 wherein said surfactant additive is employed in an amount of about 0.001 to about 5.0 weight percent.

11. The motor fuel composition of Claim 1 wherein said surfactant additive is employed in an amount of up to about 1.0 weight percent.

12. The motor fuel composition of Claim 1 wherein said hydrocarbyl-substituted dibasic acid anhydride is represented by the formula:

where R1 is a hydrocarbyl group having a molecular weight range of about 500-2500 and y has a value of 0-3.

13. The motor fuel composition of Claim 1 wherein said hydrocarbyl-substituted dibasic acid anhydride is a polyisobutenyl succinic acid anhydride of the formula:

where x has a value of about 10-25.

14. The motor fuel composition of Claim 1 wherein said polyoxyalkylene diamine is represented by the formula:

where R2 and R3 are C1-C12 alkylene groups, q and r are integers having a value of about 0-1, c has a value of from about 2-150, b+d has a value of from about 2-150, and a+e has a value of about 2-12.

15. The motor fuel composition of Claim 1 wherein said polyoxyalkylene diamine is represented by the formula:

where c has a value of about 2-50, and b+d has a value of about 2-50.

16. The motor fuel composition of Claim 1 wherein said reaction product is employed in an amount of about 0.0005 to about 5.0 weight percent.

17. The motor fuel composition of Claim 1 wherein said polymeric component is employed in admixture with a hydrocarbon solvent to facilitate the addition of said polymeric component into said mixture of hydrocarbons.

18. The motor fuel composition of Claim 1 wherein said hydrocarbon solvent comprises a light aromatic distillate composition.

19. The motor fuel composition of Claim 1 wherein said polymeric component comprises propylene with an average molecular weight of about 750-1000.

20. The motor fuel composition of Claim 1 wherein said polymeric component comprises polyisobutylene with an average molecular weight of about 100-1500.

21. The motor fuel composition of Claim 1 wherein said polymeric component comprises a mixture of (i) a major amount of polyisobutylene ethylene diamine and (ii) a minor amount of polyisobutylene in admixture with a hydrocarbon solvent.

22. The motor fuel composition of Claim 21 wherein said polyisobutylene ethylene diamine is represented by the formula:

where z has a value of about 10-40.

23. The motor fuel composition of Claim 21 wherein said polyisobutylene is represented by the formula:

where z has a value of about 10-40.

24. The motor fuel composition of Claim 1 wherein said polymeric component is employed in an amount of about 0.001 to about 1.0 weight percent.

25. The motor fuel composition of Claim 1 wherein said polyoxyalkylene glycol is selected from the group consisting of polyethylene glycol, polypropylene glycol and polybutylene glycol.

26. The motor fuel composition of Claim 1 wherein said polyoxyalkylene glycol is employed in an amount of about 0.001 to about 1.0 weight percent.

27. The motor fuel composition of Claim 1 wherein said lubricating oil is employed in an amount of about 0.001 to about 1.0 weight percent.