US3387953A - Rust-inhibited hydrocarbon fuels - Google Patents

Description

United States Patent 3,387,953 RUST-INHIBITED HYDROCARBON FUELS Roland A. Bouifard, Union, N.J., assignor to Esso Research and Engineering Company, a corporation of Delaware No Drawing. Filed May 5, 1966, Ser. No. 547,731 6 Claims. (Cl. 44-63) ABSTRACT OF THE DISCLOSURE Organo-substituted nitrogen oxides, particularly amine oxides, have been found to be very efiective inhibitors against rusting when they are added to a gasoline. The amine oxides are also effective as anti-icing agents in the gasoline. The preferred amine oxide is one that contains, in addition to the amine oxide group, at least one polar group from the class consisting of hydroxy, amine, thiol, ester, heterocyclic nitrogen, and heterocyclic oxygen groups. Particularly eifective amine oxides include bis (Z-hydroxyethyl) cocoamine oxide and 'bis(2-hydroxyethyl) tallowamine oxide. The amine oxides used in the invention can be added to a gasoline composition in a concentration within the range of about 0.2 to about 100 pounds of amine oxide per one thousand barrels of gasoline.

This invention concerns a method and composition for inhibiting the rusting characteristics of petroleum distillate products, particularly motor gasoline and aviation gasoline. Briefly, the invention involves the use of organo-su'bstituted nitrogen oxides, particularly amine oxides, and certain derivatives thereof, as rust inhibitors in gasoline whereby the rusting of ferrous surfaces brought about by the presence of traces of moisture in the gasoline is prevented. These additives also serve as anti-icing agents for gasoline.

One problem that exists in the handling and use of petroleum products is the rusting which frequently occurs in containers such as pipelines, storage tanks, engines, etc. In order to reduce and overcome the problems, many solutions have been suggested, including the development of effective rust inhibitors for petroleum products. The rusting problem which occurs in storing and using petroleum products is usually the result of traces of moisture which are inevitably present in petroleum distillates. Moisture finds its way into the distillates in a variety of ways and it is impossible to prevent entrainment of moisture in such products during storage and handling. In this connection, for example, storage tanks are generally provided with breather devices to permit the intake and exhaust of air during atmospheric temperature changes. As a result, cool, moisture-laden air is generally drawn into a storage tank at night, resulting in the condensation of moisture in the tank. A portion of this moisture is dissolved in or entrained in petroleum products when pumped from the storage tanks.

Another problem that is encountered in the use of gasoline is the tendency of a gasoline engine to stall under idling conditions in cool, humid weather. This phenomenon is well known in the art and is especially severe when the gasoline has a 50 percent ASTM distillation point of less than about 220 F. The problem is usually encountered when the relative humidity is high, i.e., above about 65 percent, and atmospheric temice peratures are above about 30 F. and below about 60 F. On a cool, moist day the refrigerating effect of evaporation of gasoline in the carburetor of the engine is suflicient to condense and freeze moisture that is present in the air entering the carburetor. This results in the formation of ice on the throttle plate and in the carburetor barrel. The more moisture there is in the entering air, the greater will be the build-up of ice. When the engine idles under these conditions, the throttle plate closes and the ice plugs oil the normal flow of air through the small clearance between the throttle plate and the wall of the carburetor barrel, thus causing the engine to stall. Usually the engine can then be restarted when the heat from the exhaust manifold melts the ice sufiiciently, but stalling will continue until the engine is sufiiciently warmed up. Eifective anti-icing agents added to the gasoline will prevent this difiiculty.

It has now been found that organo-substituted nitrogen oxides, and particularly tertiary amine oxides, are very effective inhibitors against rusting and are also efiective as anti-icing agents when incorporated into gasoline compositions.

The organo-substituted nitrogen oxides that are employed in this invention have from 6 to 50 carbon atoms and can be represented by the general formula:

wherein a, b, and c are selected from the class consisting of aliphatic, substituted aliphatic, aromatic, substituted aromatic, alkylated aromatic, substituted alkylated aromatic, cycloaliphatic, and heterocyclic radicals, including compounds wherein a and b, or a, b, and c, are portions of the same radical attached to N through -a common atom such as carbon or another nitrogen atom.

Thus, the nitrogen oxides include compounds of the type:

wherein R is the balance of a S-membered or 6-membered heterocyclic ring, and wherein the ring can include carbon, oxygen, phosphorus, sulfur, or additional nitrogen atoms.

Preferably the nitrogen oxides used in this invention are amine oxides selected from the group consisting of aliphatic, alicyclic, aromatic, and heterocyclic amine oxides having from 6 to 50 carbon atoms. More preferably, the amine oxides have at least 12 carbon atoms and no more than about 36 carbon atoms.

Representative formulas for the amine oxides are given below:

Formula 3 R2 R1-1 I)O where R, is C to C alkyl, aryl, cycloaliphatic, heterocyclic, substituted alkyl or substituted aryl, and R and R are the same or different and are C, to C alkyl, aryl, substituted alkyl or aryl, cycloaliphatic or heterocylic.

Preferably R is C to C alkyl or alkylated aryl, e.g., phenyl with C to C alkyl group, and R and R are C to C alkyl.

Formula 4 R: 15 CHz-%)Y X R:

In the above formula, R is an alkyl, aryl, alkylated aryl, or cycloaliphatic group of from 6 to 34 carbon atoms, preferably C to C R and R are each C, to C 30 alkyl groups, R is C to C alkyl, aryl, alkylated aryl or cycloaliphatic, and n is l to 6.

Formula 6 N CH2 where R is C to C alkyl, aryl, alkylated aryl, or cycloaliphatic, and n is 1 to 4.

CHg-CH: 0

where n is l to 2 and R is C to C alkyl, aryl, alkylated aryl, or cyeloaliphatic.

Organo-substituted nitrogen oxides Within the broader concept of the invention include nitrile oxides, furoxan compounds, and azoxy compounds of the following types:

Formula 8 RCEN O wherein R is a C to C aromatic hydrocarbon group or alkoxy-substituted or thioalkoxy substituted aromatic hydrocarbon group, e.g., 2,4,6-triethoxy benzonitrile oxide, or 2,6 diamyl benzonitrile oxide.

Formula 9 where R is a C to C aliphatic, aromatic, or cyeloaliphatic group, e.g., where R is ortho-dodecyl-substituted phenyl.

Formula l0 l0 RN=NR where R and R are aryl or C to C alkylated aryl, e.g., phenyl, octylphenyl, etc.

In all of the above formulas the significance of the arrow is to designate a single pair of electrons shared between the oxygen and nitrogen. This symbol is well known to organic chemists and designates a semi-polar bond wherein there is an electron transfer in the direction of the arrow. This is explained, for example, in Organic Chemistry by Fieser and Fieser, third edition, page 240.

The preparation of amine oxides involves the oxidation of tertiary amines with mild oxidizing agents such as hydrogen peroxide, perbenzoic acid, permonosulfuric acid and the like. It is particularly advantageous to employ hydrogen peroxide in the presence of glacial acetic acid and/or a lower alcohol, e.g., ethanol or isopropanol. An informative description of amine oxides and their preparation is given in Sidgwicks Organic Chemistry of Nitrogen by Taylor and Baker (1937, Oxford University Press), page 166 et seq.

Particularly useful are amine oxides derived from fatty tertiary amines, as for example those of the type of Formula 3 wherein any or all of the R groups are C to C groups derived from a fatty acid, e.g., stearic acid, or from mixed fatty acids, e.g., from coconut oil, tallow or the like. Such amine oxides Where R is long chain and R and R are short chain alkyl, e.g., methyl, isopropyl, or hy-droxy alkyl are commercially available and can be prepared as described by D. B. Lake and G. L. K. Hoh in Journal of American Oil Chemists Society, vol. 40, page 628 (November 1963). Commercial amine oxides of this type include his (Z-hydroxycthyl) cocoamine oxide, bis (Z-hydroxyethyl) tallowamine oxide, bis tfZ-hydroxyethyl) stearylamine oxide, dimethylcocoamine oxide, dimethyl hydrogenated tallowamine oxide, and dimethylhexadecylamine oxide.

To prepare compounds of the type of Formula 4, wherein Y and Z are hydroxy, a primary amine such as dodecyl amine may be reacted with two moles of alkylene oxide such as ethylene oxide, propylene oxide, octylene oxide, or decylene oxide, and the resulting hydroxy amine is mildly oxidized to the amine oxide. To prepare a compound of this type when there is only one hydroxyl group present, one can start with 1 mole of a secondary amine and react it with an equal molar proportion of an alkylene oxide and then oxidize the product to an amine oxide.

To prepare compounds of the type represented by Formula 4, wherein X, Y, and Z are all hydroxy, a dialkanol amine can be reacted with a 1,2-epoxy alkane in the presence of anhydrous aluminum chloride prior to oxidation to the amine oxide. This type of preparation is taught in US. Patent 3,202,714. One can also start with hydroxyl amine and react it with 3 moles of a 1,2-epoxy alkane, t3.g.,

An amine oxide of the type of Formula 4 where R is an alkylated aryl group can be prepared from the condensation product of an alkylated styrene oxide with a primary or secondary amine. The amine oxide from the secondary amine condensation product will have the formula:

iii. C H-C Hz-N where R is the alkyl group of the alkyl styrene oxide and R and R are alkyl, aryl, alkylated aryl or cycloaliphatic.

To prepare a compound of the type of Formula 4, wherein X and Y are amino groups, an alkylene polyamine such as diethylene triamine can be alkoxylated at just one of the amino groups, after which the product can be oxidized.

Thiol groups can be introduced by using thioepoxides in place of epoxides in any of the reactions described above. An amine oxide with ester groups can be prepared by esterifying the hydroxyl groups of a hydroxy oxide.

To prepare diamine dioxides of the type shown in Formula 5, the corresponding diamines can be oxidized by procedures disclosed in US. Patent 3,197,509.

Specific examples of compounds represented by Formula 3, wherein R R and R are unsubstituted, include diethyldecyl amine oxide, dimethylhexadecyl amine oxide and methyl isopropyl cetyl amine oxide. Specific examples of compounds defined by Formula 4 include the following:

(A) R is C alkyl; R andR are hydrogen; and X, Y, and Z are NH (B) R is C alkyl; R is methyl; R is hydrogen; X is hydrogen; and Y and Z are OH.

(C) R is C alkyl; R is methyl; and R is C alkyl; X and Y are hydrogen and Z is an SH group.

Specific compounds useful in this invention which fit Formula 5 include N,N,N'-trimethyl N-decyl ethylene diamine N,N'-dioxide and N,N,N-trimethyl N-octadecyl ethylene diamine N,N'-dioxide.

Specific compounds wherein the nitrogen is part of a heterocyclic ring include:

and

The preparation of nitrile oxides (Formula 8) and of furoxans (Formula 9) is shown by Grundmann and Dean in Journal of Organic Chemistry, vol. 30, page 2809 (August 1965).

While the simple amine oxides having only the N+O group will give satisfactory rust protection, added rust protection can be provided by using compounds wherein there are additional functional groups such as hydroxy, amino, ester, or mercapto in the beta to delta position to the nitrogen atom, most advantageously in the beta position, to increase the polarity of the amine oxide. The N O group is the active group that provides the rust inhibition. The providing of an additional polar group positioned proximate to the N O group, e.g., in the beta position, is believed to enhance the absorption of the compound on the metal surface to supply a rust protecting barrier.

The gasolines in which the additives of this invention are employed in order to prevent rust are conventional petroleum distillate fuels boiling in the gasoline range and intended for internal combustion engines, preferably spark ignition engines. Gasoline is defined as a mixture of liquid hydrocarbons having an initial boiling point in the range of about 70 to 135 F. and a final boiling point in the range of about 250 to 450 F. Gasolines are supplied in a number of different grades, depending upon the type of service for which they are intended. The additives of the invention may be employed in all of these grades but are particularly useful in motor and aviation gasolines. Motor gasolines include those defined by ASTM Specification D-439-58T, Types A, B and C. They are composed of a mixture of various types of hydrocarbons, including aromatics, olefins, parafiins, isoparaffins, naphthenes, and, occasionally, diolefins. Suitable gasolines to which the additives of the instant invention may be added include those having an octane number range of to 105 or higher, such as a clear octane number of over 90, for example, over or 100, and comprising at least 10% by volume of aromatic hydrocarbons and less than 30% by volume of olefinc hydrocarbons. These fuels are derived from petroleum crude oil by refining processes such as fractional distillation, catalytic cracking, hydroforming, alkylation, isomerization, polymerization and solvent extraction. Motor gasolines normally have boiling ranges between about 70 F. and about 450 F., while aviation gasolines have narrower boiling ranges of between F. and 330 F. The vapor pressures of gasoline as determined by ASTM Method D-86 vary between about 7 and about 15 psi. at 100 F. The amine oxides and related nitrogen oxides may also be employed in aviation gasolines which have properties similar to those of motor gasolines, but normally have somewhat higher octane numbers and narrower boiling ranges. The properties of aviation gasolines are set forth in US. Miliaiy Specification MILF5572 and ASTM Specification D-91057T.

The additives employed in accordance with this invention may be used in gasolines with other additive agents conventionally used in such fuels. It is common practice to employ from about 0.5 to about 7.0 cc./gal. of alkyl lead antiknock agents, such as tetraethyl lead, tetramethyl lead, dimethyl diethyl lead or a similar alkyl lead antiknock agent or olefinic lead antiknock agents such as tetravinyl lead, triethylvinyl lead, and the like, or a combination thereof, in both motor gasolines and in aviation gasolines, e.g., 1.0 to 3.0 cc. of a tetraethyl-leadtetramethyl-lead combination. Antiknock agents may also includes other organometallic additives containing lead, iron, nickel, lithium, manganese and the like. Other additives such as those conventionally employed in gasolines may be used such as corrosion inhibitors, antioxidants, antistatic agents, lead octane appreciators, e.g., t-butyl acetate, axiliary scavengers like tri-B-chloroethyl phosphate, dyes, anti-icing agents, e.g., isopropanol, hexylene glycol, and the like.

It has recently been found advantageous to incorporate into gasolines, and particularly those used as motor fuels, certain oil-soluble dispersants and detergents to provide significant improvement in overall engine cleanliness. This is taught, for example, by Calvino et al. in US. Patent 3,223,495. These dispersants function not only to maintain a high level of cleanliness in the fuel lines and carburetor region of the internal combustion engine, but also serve to bolster the action of dispersants that have been added to the crankcase lubricant. A certain portion of the dispersant that has been added to the gasoline finds its way past the piston rings and helps to inhibit the deposition of varnish and sludge in the regions of the engine that are normally contacted only by the lubricant. The additives of the present invention may advantageously be used in gasoline compositions containing such dispersants.

The gasoline compositions embodying this invention will contain from about 0.2 to about 100 pounds of organo nitrogen oxide per thousand barrels of gasoline. More usually from about 1 to 50 pounds per thousand barrels will be employed and preferably from about 2 to 10 pounds per thousand barrels, if the additive is to be used primarily for rust protection. The preferred range is from 2 to 30 pounds per thousand barrels if the organo nitrogen oxide is to serve also as an anti-icing additive. If a dispersant is also employed in the gasoline, from 5 to 200 pounds, or more usually from about 10 to 100 pounds, of dispersant will be used per thousand barrels of gasoline. It is frequently desirable also to incorporate a solvent oil into the gasoline in order to reduce intake valve deposits. It a solvent oil is used, it

may be convenient to blend the dispersant and the solvent oil together and add the blend to the gasoline. A particularly preferred solvent oil will have a boiling range within the limits of about 350 to 800 F. at l mm. of mercury pressure. More preferably, the boiling range is about 400 to 700 F. at the reduced pressure. Solvent oils having a viscosity within the range of 45 to 150 SSU at 210 F. are usually preferred.

For those amine oxides and the organo nitrogen oxides of the present invention that have only limited solubility in gasoline, it is usually not economic to prepare a concentrate of such additive in a gasoline fraction for subsequent dilution blending. Many of the amine oxides can be employed as to 60 wt. percent concentrates in a lower aliphatic alcohol such as methyl or isopropyl to aid in the blending operation. The alkanol thus incorporated along with the additive will not be detrimental in the gasoline and may in fact enhance the anti-icing action of the amine oxide. The concentrate of amine oxide in isopropyl alcohol can be such that when blended into gasoline there may be supplied 1 to 2 wt. percent of the alcohol as an anti-icing agent along with the desired amount of amine oxide for rust protection. The amine oxide or its concentrate in an alcohol may be added conveniently to the gasoline by means of an in-line proportionating blender. Core centrates comprising to 60 percent of a C to C alcohol or a 50 mixture of such alcohol and xylene, 40 to 50 percent dispersant, and 2 to 4 percent amine oxide can be prepared for subsequent blending into gasoline. Mixed aromatic hydrocarbons, or a heavy aromatic naphtha, or a fraction in the gasoline range from a hydrofining operation, may be employed in place of or in conjunction with the xylene.

The nature of this invention and the advantages accruing from the practice thereof will be better understood when reference is made to the following examples, which include a preferred embodiment:

EXAMPLE 1 A number of gasoline blends were prepared and subjected to a rust test which was a modification of ASTM Test D-665. In this test, 350 ml. of gasoline maintained at a temperature of 77 F. is stirred with a polished soft steel spindle. After ten minutes of stirring, for the purpose of conditioning the spindle, 50 ml. of the gasoline is removed and discarded, 30 ml. of distilled water is added, and stirring is continued for one hour, with the temperature being maintained at 77 F. The steel spindle is then removed from the mixture of gasoline and water and inspected for rust spots. Rusting that does not exceed 5 percent of the area is considered satisfactory.

The gasoline that was used in preparing the blends that were subjected to this rust test had the following inspections given in Table I:

Table I.Base gasoline inspections ASTM Distillation, Method D-86z Using the gasoline described above, blends were prepared with various additives which were added by simple mixing. These blends were then subjected to the rust test described above, duplicate tests being run for each blend. Some of the blends tested contained one of a number of prior art additives advocated as anti-rust additives. Other blends contained an amine oxide of the present invention. In a second set of blends a dispersant was also present in the gasoline. The various additives used and the results obtained in the duplicate test are given in the following Table II. Where the area rusted was too small to express as a percentage, the rusting is reported as the number of specks of rust observed. In each case where an additive concentrate was used, the indicated amount added was of the concentrate. The designation p.t.b. in Table II means pounds per thousand barrels. (1 bbl.=42 gal.)

Table II Anti-rust additive: Percent area rusted None 100; 100 Amine oxide AF 1 p.t.b O; 0 Amine oxide B, 2 p.t.b 0; 1 speck Amine oxide B, 5 p.t.b Amine oxide 0, 2 p.t.b 0; 2 specks Amine oxide C, 3 p.t.b 0; O Additive X, 3 p.t.b 50; 50 Additive Y, 5 p.t. b 20; 40 Additive Z, 7.7 p.t.b 95 .Dispersant blend without anti-rust additive 75; 75 .lDispersant blend plus 1 p.t.b. amine oxide A 5 specks; 5 specks .Dispersant blend plus 2 p.t.b. amine oxide A 1 speck; 2 specks 1 In each case where a. concentrate was used the indicated amount of additive is of the concentrate.

's(2-hydroxyethyl) cocoamine oxide. Mol. wt. 301. Comal product. 50 Wt. percent concentrate in lower alcohol. a methyl cocoamine oxide. Commercial product. 40 wt. percent concentrate in lower alcohol.

4 Bis(2hydr'oxyethyl) tallow amine oxide. Commercial product. M01. wt. 366. 50 wt. percent concentrate in lower alcohol.

nl3utyl amine salt of mixed monoand di-phosphates of C13 0x0 alcohol. 75 Wt. percent concentrate in kerosine. (See British Patent 1,001,470.)

Dimer of linoleic acid plus a phosphorus compound. (Santolene (5.)

Mixed monoand iii-amides of long chain diamine and oleic acid. {MFA-85.)

It will be seen from the data in Table II that amine oxides of the present invention were much more effective than any of the prior art anti-rust agents and that the amine oxide also provided satisfactory rust protection when a dispersant was present.

The dispersant used in the dispersant blends mentioned above was prepared by chlorinating polyisobutylene of about 780 molecular weight at about 250 F. to a chlorine content of about 4.3% and then condensing the chlorinated polyisobutylene with acrylic acid at 250 F. to 425 F. to form polyisobutylene propionic acid. Seventy parts of the polyisobutylene propionic acid were then mixed with 32 parts of a mineral lubricating oil of 150 SSU viscosity at F. and the mixture was reacted with 3.4 parts of tetraethylene-pentaamine at 300 F. for about nine hours to give a concentrate containing about 70 wt. percent of reaction product and 30 wt. percent of diluent mineral oil. This concentrate was added to the gasoline by simple mixing in the amount of 25 pounds per thousand barrels to form the dispersant blends referred to.

EXAMPLE 2 The effect of an amine oxide in reducing carburetor icing was determined by using a standardized carburetor icing test procedure. In brief, the operating conditions used for conducting the tests were as follows: 40 F. intake air temperature, 90% i5% humidity, and continuous air circulation.

The procedure used the following steps: (1) Start cold engine; {2) accelerate to 1500 r.p.m. and maintain for one minute; (3) decelerate to idle r.p.m. and idle engine for one-half minute; (4) observe and record engine stalling characteristics; (5) if engine stalls, immediately restart and rerun the cycles described by items 1 through 3.

The engine, atmospheric conditions and operating procedure are selected to emphasize icing conditions so that the reduction of ice formation attributable to an additive would be further reduced several fold under normal consumer conditions. Except that the engine load and speed must be low, the selection of optimum speeds for carburetor icing tests is relatively flexible. In general, the throttle opening should be at a minimum adjustment for prolonged engine warm-up and for maximum throttle blade exposure to the moist air. At the same time the throttle must be sufficiently opened to cause adequate fuel flow through primary jets of the carburetor so that freezing temperatures will result from vaporization of the volatile gasoline.

Engine speed to attain these conditions was established at 1500 rpm; and although ice formation begins on the throttle blade at this speed, the engine seldom, if ever, stalls until the speed is reduced to idle. When decelerating from 1500 rpm. to idle, the air crack between the throttle valve and throttle body begins filling with ice, shutting off air into the manifold. Just prior to stalling, the air fuel ratio becomes excessively rich and occasionally causes the engine to buck before stalling. It should be noted that the engine sometimes idles throughout the allotted 30-second period without stalling but that bucking is observed, thus suggesting that a stall almost occurred.

Using this procedure, a volatile winter-grade base gasoline and the same gasoline containing pounds per thousand barrels of bis(2-hydroxyethyl) cocoamine oxide were compared for their tendency to cause stalling as the result of icing of the carburetor. A Ford engine having a 4-barrel carburetor was used in the tests. The base gasoline used had the inspections given in Table III:

Table III.-Base gasoline inspections F. Initial boiling point 86 vol. percent evaporated at 147 50 vol. percent evaporated at 186 80 vol. percent evaporated at 260 Final boiling point 390 The results obtained, which are given in Table IV, show that the amine oxide effectively reduced the stalling To the base gasoline described in Table I there is added trilauryl amine oxide in the amount of 4 pounds per thousand barrels.

EXAMPLE 4 To a regular grade gasoline having an ASTM 50 percent distillation point of about 208 F. and containing about 2.8 cc. of lead tetraethyl per gallon, there are added as a dispersant 20 pounds per thousand barrels of a polyisobutenyl succinimide of tetraethylene pentamine (polyisobutenyl group of about 950 mol. wt.) (i.e., a dispersant of Type C of U.S. Patent 3,223,495) and as an antirust agent about 6 pounds per thousand barrels of an amine oxide of Formula 7 of the present disclosure, wherein n is 1 and R is a lauryl group. The compound is prepared as taught in U.S. Patent 3,098,794.

EXAMPLE 5 To separate portions of a gasoline of 95 research octane number containing 2.5 cc. of lead tetraethyl per gallon and having 21 volume percent aromatic hydrocarbons, the gasoline having a 55% boiling point of 212 F. and a final boiling point of 395 F. (ASTM Method D-86), blends of gasoline having improved anti-rust properties are prepared by adding organo-substituted nitrogen oxides as designated below:

GASOLINE DLENDS Amount Added Blend Additive (Pounds Per 1000 Barrels) A 2,4,6-trimcthoxy bcnzonitrile oxide 4 B Azoxybenzenen 5 O N ,N,N-trimeth cyl ethylene di- 3 amine N,N dio. e. D Cetyl methyl propylamine oxide 12 E Oxide of condensation product of decyl 8 styrene oxide and di-n-butyl amine. F N Ilagryl tri5ethoxy) dimethyl amine 10 0x1 e. G Tristcaryl amine oxide i. 3 H fl-hydroxypropyl bis(Ci2Cn coco 6 amine oxide. I Bis(fi-thiopropyl) stcaryl amine 2 oxide 4 J Dimcthyl O1zAliol amine oxide 2 1 Prepared from CiTCl-i fraction of coconut oil fatty acids; approximate ratio 2 parts C12 to 1 part C14.

2 Prepared from reaction of 1 mole of stearyl amine and 2 moles of propylene episulfide.

The C Alfol group referred to above designates a straight-chain primary alkyl group derived from petrochemical raw materials as referred to by Lake and Hoh, supra.

It is to be understood that this invention is not to be limited to the specific embodiments herein presented by Way of example. The scope of the invention is to be determined by the appended claims.

What is claimed is:

1. A gasoline composition comprising a major proportion of gasoline, and a minor rust-preventing proportion of a gasoline-soluble amine oxide having from about 6 to about 50 carbon atoms, said amine oxide having, in addition to the oxide group, at least one polar group from the class consisting of hydroxy, amine, thiol, ester, heterocyclic nitrogen, and heterocyclic oxygen groups.

2. A composition as defined by claim 1 wherein said amine oxide has the formula:

wherein R is selected from the class consisting of alkyl, aryl, alkylated aryl, substituted aryl, and cycloaliphatic groups of from 6 to 24 carbon atoms, R is hydrogen or a methyl group, R is hydrogen or a C to C alkyl group, and X, Y, and Z are selected from the class consisting of hydrogen, hydroxy, amino, thiol and ester groups, at least one of X, Y and Z being other than hydrogen.

3. A composition as defined by claim 1 wherein said amine oxide has in the range of 12 to 36 carbon atoms.

4. Composition as defined by claim 1 wherein said amine oxide is a tertiary amine oxide having at least one C to C alkyl group derived from a fatty acid.

5. A gasoline composition comprising a major proportion of gasoline, and a minor rust-preventing proportion of his (2-hydroxy ethyl) cocoamine oxide.

6. A gasoline composition comprising a major proportion of gasoline, and a minor rustpreventing proportion of his (2-hydroxy ethyl) tallow amine oxide.

References Cited UNITED STATES PATENTS 2,490,744 12/ 1949 T rigg et a1 252-5 1.5 2,699,427 1/ 1955 Smith et a1 25233.6 3,277,003 10/ 1966 Grayson a- 252392 3,007,784 11/ 1961 Ebner 4472 DANIEL E. WY MAN, Primary Examiner.

Y. H. SMITH, Assistant Examiner.

ammrsrsmszin UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,387,953 June 11, 1968 Roland A. Bouffard It is certified that error appears in the above identified patent and. that said Letters Patent are hereby corrected as shown below:

Column 2, Formula 3, at the extreme bottom "R should read R Column 3, Formula 4, at the extreme left, "R should read R line 23, "Example 5" should read Formula 5 Column 10, claim 2, at the extreme bottom of the formula "R" should read R Signed and sealed this 16th day of September 1969.

(SEAL) Attest:

Edward M. Fletcher, Jr.

Attesting Officer Commissioner of Patents WILLIAM E. SCHUYLER, IR.