US3480414A - Broad spectrum fuel additives - Google Patents

Description

United States Patent US. Cl. 44-72 2 Claims ABSTRACT OF THE DISCLOSURE The fiuoborate salts of aliphatic hydrocarbon substituted alkylene diamines are provided for fuel detergents as well as antiicing and antirust agents.

This invention concerns novel additives for fuels which greatly enhance a broad spectrum of fuel properties.

Numerous additives are added to fuels to improve the operation of combustion engines. Antiicing additives are necessary because in cold weather gasoline evaporation in the carburetor has sufi'icient refrigerating effect to condense and freeze moisture present in the air. The resulting ice particles deposit on the metal surfaces of the carburetor and partially or completely block the air passage between the carburetor throat and the carburetor throttle valve causing stalling, particularly when the engine is idling.

Antirusting additives are necessary during the handling of hydrocarbon liquids. It is frequently necessary to transport and/or store the liquids in steel or iron containers or pipelines. Almost invariably, the hydrocarbon liquids contain traces or more of water which react with the container resulting in rusting and contamination of the hydrocarbon liquid. This problem is especially serious when handling gasoline, kerosene, fuel oil, diesel fuel, etc.

Numerous other additives are frequently included to provide detergency, antiknock properties, lead scavenging, oxidation inhibition, antistatic properties, copper deactivation, etc. As is evident, each of these various additives must be compatible with all the other necessary additives and none of them may significantly interfere with the smooth operation of the combustion engine, the ultimate evaluation of the eifectiveness of a fuel.

Pursuant to this invention, fuels having greatly improved properties are obtained by incorporating in the fuel an effective amount of the novel fluoborate salts of N-aliphatic hydrocarbon substituted alkylene diamines, wherein the aliphatic hydrocarbon group is of from about to 30 carbon atoms, preferably from about 12 to 24 carbon atoms and the alkylene group is of from 2 to 3 carbon atoms.

For the most part, the compositions of this invention will have the following formula:

RNHANH HBF wherein R is an aliphatic hydrocarbon group (alkyl or alkenyl) of from 10 to 30 carbon atoms, more usually of from 12 to 24 carbon atoms and A is an alkylene group of from about 2 to 3 carbon atoms. The proton from the fluoboric acid may be bonded to either of the nitrogens; that is, depending on the character of R, the proton may be bonded to the secondary amine or the primary amine nitrogen or a mixture of both.

The fluoborates are prepared by reaction of the N-aliphatic hydrocarbyl alkylene diamine with fluoboric acid which may be formed by reacting boron trifiuoride with hydrogen fluoride or hydrofluoric acid with boric oxide. The fluoboric acid is commercially available as an aqueous solution of approximately 48 percent concentration and 3,480,414 Patented Nov. 25, 1-969 will generally be used as such. Upon addition of the diamine to the aqueous solution of the fluoboric acid, the fluoborate salt is formed in a moderately exothermic reaction. Benzene may then be added or be included initially and the water removed by azeotropic distillation.

The diamines have the following formula:

R NHA NH wherein R is an aliphatic hydrocarbyl group of from 10 to 30 carbon atoms, more usually of from 12 to 24 carbon atoms, and A is alkylene of from 2 to 3 carbon atoms, i.e., ethylene and propylene (1,2- or l,3-). The diamines of the above formula are generally commercially available and derived from natural sources. However, the alkyl group may also be prepared by synthetic means.

In the preparation of the fluoborates, individual diamines may be used or mixtures having average molecular weights. Therefore, Within the scope of this invention some of the diamines in the mixture may be outside the designated range, as long as a major proportion of the N-alkyl diamine used is within the designated carbon atom range. The aliphatic hydrocarbon group may be aliphatically saturated or unsaturated, e.g., ethylenic unsaturation, usually free of acetylenic unsaturation. The aliphatic group may be straight chain or branched chain usually being straight chain.

Illustrative aliphatic hydrocarbon groups are oleyl, hexadecyl, eicosyl, polyisobutenyl, polypropenyl, pentapropenyl, hexapropenyl, tetraisobutenyl, tetradecyl, behenyl, arachidyl, etc.

The fluoborate salts of the N-alkyl alkylene diamines can be used in a number of fuels to greatly enhance the properties of the fuel for use in combustion engines. Depending on the particular fuel, the additives of this invention may be used for different purposes. As already indicated, the additives of this invention provide deicing or antistalling properties, rust inhibiting properties or corrosion inhibiting properties, as well as some detergency.

Generally, the additives will be present in at least 15 parts per million, usually at least 50 parts per million and generally not greaterthan about 0.1 weight percent. Most frequently, excellent results will be obtained with concentrations of from about 100 to 5,000 p.p.m.

The additives of this invention are particularly useful with volatile fuels having Reid vapor pressures above about 9. These are generally winter gasolines employed in northern areas where the Reid vapor pressure is generally between about 9 and 13.5.

The following example is offered by way of illustration and not by way of limitation.

EXAMPLE I Into a reaction vessel was introduced 17.6 g. (0.1 mole) of fluoboric acid as an approximately 50 weight percent solution in Water and g. of benzene. The mixture was stirred at room temperature and then 35.6 g. (0.1 mole) of N-(alkyl) propylene diamine (where the alkyl group is of from 15 to 20 carbon atoms and supplied by Armour Chemical Company as Duomeen L-lS) was slowly added, resulting in a moderately exothermic reaction. At the end of the addition, the benzene and water were removed by azeotropic distillation and the residue isolated as product.

-In order to demonstrate the effectiveness of the compositions of this invention as antistalling/antiicing additives, the following test was carried out. In the first test, a pump is used to pull an air-fuel mixture (l00 percent relative humidity, 40 F.) through a simulated carburetor. The apparatus is sized and operated to simullate the operation of a carburetor on a 1965 slant-six 225-cubic inch Plymouth engine operating at 1500 rpm. with an air-fuel mixture of 14:1 and a manifold vacuum of -12" Hg. Evaporation of the gasoline in the glass tube cools the moist air with resulting ice formation on the perforated throttle plate. The ice on the plate restricts the flow of the air-fuel mixture, causing the pressure to change. The time that additives in the fuel delay formation of ice on the plate as measured by a pressure increase of 4" Hg is called the induction period and is a measure of the effectiveness of the additive. The winter grade gasolines A and B used in the test give a stall in about 42 seconds, while the winter grade gasoline C gives a stall in about 17 seconds.

TABLE I Conc., Induction No. of deter- Additive, Ex. ppm. period minations Fuel 1 100 114 10 A 100 170 5 B 100 87 C K The fuels are commercially available base fuels.

Boiling midpoint, F.

A 1-88192 B 213 C 198-200 Additives which provide stalling times of over 100 seconds for the A and B gasolines and 50 seconds for the C gasoline under the above described test conditions are regarded as effective antistalling, antiicing additives.

The additive of Example I and the fluoborate salt of N-aminopropyl-Z-amino C alkane (supplied by Armour Chemical Co. as Duomeen L-11) (prepared as described in Example I) were tested in a Lab Engine test as follows:

The carburetor which is used is designed for the 1965 Plymouth 225-cubic inch engine and is employed with at Plymouth L-head 23'0-cubic inch engine. The carburetor is thermally isolated from the engine and during the test is maintained in a warmed-up condition by a controlled heating element. When the equilibrium temperature has been established in the carburetor, the engine is started and accelerated to 2400 r.p.m., no load, where it is operated for seconds. The engine speed is then dropped to idle (525-550 r.p.m.) for 15 seconds. As soon as the engine stalls, or at the end of 15 seconds, it is accelerated again to 2400 rpm, no load. This cycle is repeated 14 times, during which time the intake air and the carburetor are gradually warmed up.

The air which is used is initially at F. and 100% relative humidity and gradually rises to F. during the course of the determination.

The following table indicates the effect of the antiicing additives of this invention on reducing the number of stalls with troublesome winter fuels. The results are reported as number of talls.

TABLE II N o. of deter- Additive, Ex. Cone, ppm. Stalls minations I 30 5. 7 12 Base Fuel 7. 4. 12 II 30 6. 6 5 Base Fuel 7. 7 10 In addition to the above demonstrated antiicing action of the fiuoborate salts of diamines, these additives are also effective in suppressing surface ignition in spark plug fouling in gasoline fuels, as detergents and as rust inhibitors. I

In order to demonstrate the excellent effectiveness of the compositions of this invention as rust inhibitors, a particularly bad fuel, as far as rusting is concerned, was tested according to the rusting test ASTM D 665-60, using synthetic water. The fuel is a hydrofined straight run distillate (boiling range350650 F.). The rating is based on a scale of from 1 to 7, 7 being completely rusted and 1 being no rust. One hundred ppm. or the composition of Example I was used in the fuel and the test carried out for 20 hours at F. The fuel without the additive had a rating of 7, while the fuel with the additive had a rating of 1, shownng excellent rust protection.

It is evident from the above results that the compositions of this invention provide a broad spectrum of enhanced properties to fuels. In this way, rather than having a variety of different additives, each of which must be compatible with the other, one additive is capable of fulfilling a number of functions. Not only is the use of a single additive more efficient, but also cheaper.

As will be evident to those skilled in the art, various modifications on this invention can be made or followed, in the light of the foregoing disclosure and discussion, without departing from the spirit or scope of the disclosure or from the scope of the following claims.

I claim:

1. Fuel compositions comprising a liquid hydrocarbon fuel and in an amount sufficient to provide deicing and/ or corrosion inhibition protection, a fiuoborate salt of N-aliphatic hydrocarbon substituted alkylene diamines, wherein the aliphatic hydrocarbon group is of from about 10 to 30 carbon atoms and the alkylene group is of from 2 to 3 carbon atoms.

2. A composition according to claim 1, wherein said aliphatic hydrocarbon group is of from 12 to 24 carbon atoms.

References Cited UNITED STATES PATENTS 3,118,745 1/1964 Knowles et al. 4472 DANIEL E. WYMAN, Primary Examiner Y. H. SMITH, Assistant Examiner US. Cl. X.R. 252-389