DE69115894T2 - ENGINE FUEL ADDITIVES COMPOSITION AND METHOD FOR THEIR PRODUCTION - Google Patents

Abstract

A motor fuel additive composition comprises a mixture of:(a) from 5-50 weight percent, based upon the total weight of the additive, of a detergent component selected from the group consisting of (i) at least one nonionic compound having a molecular weight in the range of 200-1500, (ii) a reaction product of a substituted hydrocarbon and an amino compound, and (iii) a polybutylamine or polyisobutylamine; and (b) a fuel conditioner component comprising (i) from 2-50 weight percent, based upon the total weight of the additive, of a polar oxygenated hydrocarbon compound and (ii) from 2-50 weight percent, based upon the total weight of the additive, of an oxygenated compatibilizing agent. The fuel conditioner component may additionally comprise a hydrophilic separant, an aromatic hydrocarbon, or mixtures thereof. The additive may also additionally comprise a carrier oil or fluidizer. The additive is prepared by mixing together the detergent and fuel conditioner components, and is advantageous in that the detergent and fuel conditioner components synergistically interact to reduce both fuel intake system deposit formation and combustion chamber deposit formation, thereby inhibiting engine ORI.

Description

Background of the invention

This invention relates to an additive for a motor fuel and a process for producing such an additive.

More particularly, this invention relates to a motor fuel additive comprising a) a detergent selected from the group consisting of (i) a reaction product of a substituted hydrocarbon and an amine, and (ii) a polybutylamine or polyisobutylamine; and (b) a fuel conditioning compound comprising (i) a polar oxygenated hydrocarbon and (ii) an oxygenated compatibilizing compound. This invention also relates to a process for preparing a motor fuel additive comprising mixing the above-described reaction product and the fuel conditioning compounds.

The incomplete combustion of hydrocarbon-containing motor fuels in an internal combustion engine is a common problem which generally leads to the formation and accumulation of carbon and other deposits at various locations, including the fuel delivery system. Considerable efforts have previously been made to develop additives for fuels which reduce or prevent the formation of deposits in the fuel delivery system of the engine. At first, the so-called "first generation" additives, which were primarily intended to clean the carburetors and injectors, comprised low molecular weight amine derivatives such as fatty amines, amides, amidoamines and imidazolines. Later developed so-called "second generation" additives, which were intended to clean both the intake valves and the carburetors and injectors, were primarily based on polyolefins, in particular on polyisobutenes and their derivatives. For example, the use of polybutyl succinimide as a fuel additive is described in US Patent No. 3,443,918 (Kautsky et al.) and US Patent No. 3,170,892 (Leseur et al.); the use of polybutyl amines as a fuel additive is described in US Patent No. 3,438,757 (Honnen et al.); the use of a fuel system-only cleaning mixture based on an oxygen compound and a dispersant is described in US Patent No. 3,658,494 (Dorer, Jr.).

For effective deposit control, it has been common to use such additives in conjunction with petroleum or synthetic-based carrier oils. Petroleum-based oils useful in this regard include relatively high-viscosity naphthenic and paraffinic oils, including so-called solvent neutral oils such as SNO-500 and SNO-600 and so-called top cylinder oils and other similar oils. Synthetic oils that have been used heretofore include low molecular weight polypropylene and polyisobutylene, as well as polyalkylene oxides.

Although the additives described above have been shown to be effective in reducing deposits in the fuel intake system, the increasing use of these additives, particularly second generation additives, in fuels has led to an increase in deposits in the combustion chamber. The presence of deposits in the combustion chamber significantly reduces engine efficiency for several reasons. First, the accumulation of deposits within the combustion chamber prevents heat exchange between the chamber and the engine cooling system. This leads to higher temperatures in the combustion chamber, which results in increases in the end gas temperature of the incoming charge. Consequently, Auto-ignition of the end gas occurs, causing the engine to knock. In addition, the build-up of deposits in the combustion chamber reduces the volume of the combustion zone, creating a higher compression ratio in the engine than intended. This in turn also causes severe engine knocking. A knocking engine does not use the combustion energy effectively. In addition, prolonged engine knocking causes fatigue stress and wear of essential parts of the engine. The phenomenon described above is characteristic of gasoline-powered engines. It is usually remedied by using a higher octane gasoline to power the engine and has since become known as the octane requirement increase (ORI) phenomenon.

Therefore, it is clearly advantageous to use in engine oils an additive which reduces deposits in the fuel intake system and prevents the formation of deposits in the combustion chambers, thereby reducing or at least modifying the composition of the deposits which cause an Octane Demand Increase (ORI). An object of this invention is to provide an additive for a motor fuel which is useful for preventing deposits in both the fuel intake system and the combustion chambers. It is a feature of this invention that the additive contains a detergent and a fuel conditioning compound which work synergistically together to reduce the formation of deposits in both the fuel intake system and the combustion chamber. It is an advantage of this invention that it reduces both the formation of deposits in the engine's fuel intake system and the octane requirement increase associated with the formation of deposits in the combustion chamber.

Another object of this invention is to provide a process for preparing an additive for a motor fuel which reduces deposits in the fuel intake system of the engine and also in the combustion chambers, thereby reducing octane demand increase. It is a further feature of this invention that an additive is prepared by mixing a detergent and a fuel conditioning compound which work synergistically together to reduce the formation of deposits in the fuel intake system and the octane demand increase associated with the formation of deposits in the combustion chamber.

Summary of the invention

The additive for a motor fuel according to the invention contains a mixture of:

(a) 5-50% by weight, based on the total weight of the additive of a detergent selected from the group consisting of :

(i) a reaction product of:

(A) a substituted hydrocarbon of the formula

R1 - X (I)

wherein R₁ is a hydrocarbon radical having a molecular weight in the range of 150-10,000 and X is selected from the group consisting of halogens, succinic anhydride and dibasic succinic acid, and

(B) an amine of the formula

H - (NH - (A)m)n - Y - R₂ (II)

in which Y is O or NR₅ and R₅ is H or a hydrocarbon radical having 1-30 carbon atoms; A is a straight-chain or branched alkylene radical having 1-30 carbon atoms; m has a value in the range of 1-15; n has a value in the range of 0-6; and R₂ is selected from the group consisting of H, a hydrocarbon radical having a molecular weight in the range of 15-10,000, and a homopolymeric or heteropolymeric polyoxyalkylene radical of the formula

R3; - ( (Q)a(T)b(Z)C)d - (III)

where R₃ is H or a hydrocarbon radical having 1-30 carbon atoms, Q, T and Z are polyoxyalkylene radicals having 1-6 carbon atoms, a, b and c each have values between 0 and 30 and d has a value in the range between 1 and 50, and

(ii) a polybutylamine or polyisobutylamine of the formula

in which R₁₁ is a polybutyl or polyisobutyl radical derived from isobutene and up to 20% by weight of n-butene, and R₁₂ and R₁₃ are the same or different and each represent hydrogen, an aliphatic or aromatic hydrocarbon radical, a primary or secondary, aromatic or aliphatic aminoalkylene or polyaminoalkylene radical, a polyoxyalkylene, a heteroaryl or heterocyclyl radical, or together with the nitrogen atom to which they are attached, in which further heteroatoms may be present; and

(b) a fuel conditioning compound containing:

(i) 2-50% by weight, based on the total weight of the additive, of a polar, oxygen-containing hydrocarbon having an average molecular weight in the range between 250-500, an acid number in the range between 25-175, and a saponification number in the range of about 30-250 and

(ii) 2-50% by weight, based on the total weight of the additive, of an oxygen-containing compatibilizing compound having a solubility parameter in the range of about 8.8-11.5 and a moderate to strong hydrogen bonding ability.

The fuel conditioning compound may additionally contain a hydrophilic release agent such as a glycol monoether and an aromatic hydrocarbon such as xylene. The additive may additionally contain a carrier oil or a liquefier.

The invention is also directed to a process for preparing the motor fuel additive of the invention, in which a detergent and fuel conditioning compounds are mixed to obtain the additive. The motor fuel additive of the invention has the advantage that the detergent and fuel conditioning compounds act synergistically in reducing both deposits in the fuel inlet system and the formation of deposits in the combustion chamber, thereby improving the performance of the engine is improved and the octane requirement is reduced.

Short description of the drawings

Fig. 1 shows the results of engine test runs with different fuel compositions, whereby fuel compositions containing the additive according to the invention are also used.

Fig. 2 shows the results of engine test bench runs of Fig. 1 for various fuel compositions including motor fuels with the additive according to the invention as a diagram in which the combustion chamber rating is plotted against the deposits in the inlet valve (in mg).

Description of the preferred embodiment

The invention is directed to an additive for a motor fuel and a process for its preparation. The additive contains (a) a detergent selected from the group consisting of (i) the reaction product of a substituted hydrocarbon and an amine, (ii) a polybutylamine or polyisobutylamine; and (b) a fuel conditioning compound comprising a polar oxygenated hydrocarbon and an oxygenated compatibilizing compound.

If the above reaction product is used as detergent, then the substituted hydrocarbon used to prepare the reaction product has the formula

R1 - X (I)

where R₁ is a hydrocarbon radical with a molecular weight in the range between 150 to 10,000, preferably a polyalkylene radical with a molecular weight in the range between 400 to 5,000, most preferably a polyalkylene radical with a molecular weight in the range of 60 to 1,500, and X is selected from the group consisting of halogens, preferably chlorine, succinic anhydride and dibasic succinic acid. In a preferred embodiment, R₁ - X is a polyisobutylsuccinic anhydride. In another preferred embodiment, R₁ - X is a chloropolyisobutylene.

The amine used to produce the reaction product has the formula

H - (NH - (A)m)n - Y - R 2 (II)

where Y is O or NR₅ and R₅ is H or a hydrocarbon radical having 1 to 30, preferably 1 to 22 carbon atoms, A is a straight-chain or branched alkyl radical having 1 to 30, preferably 1 to 15 carbon atoms, m has a value in the range from 1 to 15, preferably 1 to 12, n has a value in the range from 0 to 6, preferably 0 to 5 and R₂ is selected from the group consisting of H, a hydrocarbon radical having a molecular weight in the range from 15 to 10,000, preferably 15 to 2,000 and a homopolymeric or heteropolymeric polyoxyalkylene radical of the formula

R3; - ((Q)a(T)b(Z)c)d- (III)

where R3 is H or a hydrocarbon radical having 1 to 30, preferably 1 to 22 carbon atoms, Q, T and Z are polyoxyalkylene radicals having 1 to 6 carbon atoms, a, b and c each have values between 0 to 30 and d has a value in the range from 1 to 50, preferably 1 to 25.

Various preferred meanings of the amine of formula (II) are given in the following Table 1: Table 1 gives an amine of the formula: R₂=Oleyl residue gives an amine of the formula: Oleyl

In another preferred embodiment, R₂ is the homopolymeric or heteropolymeric polyalkylene radical of formula (III) described above. The terms homopolymeric and heteropolymeric used in this description and the claims refer to polyalkylene compounds which, in the case of homopolymeric compounds, have one repeating polyoxyalkylene group and, in the case of heteropolymeric compounds, have more than one repeating polyoxyalkylene group, typically having 1 to 6 carbon atoms, such as ethylene oxide (EO), propylene oxide (PO) or butylene oxide (BO). For example, in one embodiment, R₂ may be a homopolymeric polyoxyalkylene radical of formula

R₃ - ((EO))d -

where in the formula (III), a=1, b=0, c=0, Q=ethylene oxide and R₃ and d have the meanings described above. In another embodiment, R₂ can be a heteropolymeric polyalkylene radical of the formula

R3; - ((EO)a (PO)b (BO)C)d-

where in formula (III), Q=ethylene oxide, T=propylene oxide, Z=butylene oxide and a, b, c, d and R₃ have the meanings described above.

In a further preferred embodiment, the amine described above is selected from the group consisting of polyethylene polyamines, polypropylene polyamines and mixtures thereof. In a further preferred embodiment, such polyamines are monoalkylated.

The reaction product is preferably prepared by reacting the substituted hydrocarbon R1 - X with the amine in a molar ratio in a range of 0.2:1 to 20:1, preferably in the range of 0.5:1 to 10:1. The reaction product can be prepared under reaction conditions (including, for example, reaction times, temperatures and proportions of starting materials) familiar to those skilled in the art for preparing such reaction products from an amine and a substituted hydrocarbon. The process for preparing such reaction products is described, for example, in U.S. Patent No. 3,172,892 (Leseur et al.), U.S. Patent No. 3,438,757 (Honnen et al.) and U.S. Patent No. 3,443,918 (Kautsky et al.).

The detergent may also be a polybutylamine or polyisobutylamine of the formula

in which R₁₁ is a polybutyl or a polyisobutyl radical, which is derived from isobutene and up to 20% by weight from n butene and R₁₂ and R₁₃ are the same or different and each represent a primary or secondary, aromatic or aliphatic aminoalkylene radical or a polyaminoalkylene radical, a polyoxyalkylene radical or a heteroaryl or heterocyclyl radical or together with the nitrogen atom to which they are bonded form a ring in which further heteroatoms may be present.

Compounds of the general formula (IV) and the process for their preparation are described, for example, in US Patent No. 4,832,702 (Kummer et al.). Compounds of the general formula (IV) are preferably prepared according to the process which is described in US Patent No. 4,832,702. In this process, a suitable polybutene or polyisobutene is hydroformylated with a rhodium or cobalt catalyst in the presence of CO and H₂ between 80 and 200°C and at CO/H₂ pressures of up to 600 bar and the oxo product formed is then subjected to a Mannich reaction or an amination in the presence of hydrogen, the amination preferably being carried out between 80 and 200°C and under pressures of up to 600 bar, preferably between 80 and 300 bar.

The fuel conditioning compound used to prepare the additive of the present invention in admixture with the detergent may preferably be the fuel conditioning compound previously described in U.S. Patent No. 4,753,661 (Nelson et al.). This fuel conditioning compound contains a polar oxygen-containing hydrocarbon compound and an oxygen-containing compatibilizing substance.

The proportion of polar oxygenated hydrocarbons in the fuel conditioning compound refers to mixtures of various organic compounds that are formed during the controlled oxidation of liquid petroleum with air. These air oxidations of liquid distillates are often carried out at temperatures between about 100 to 150ºC in the presence of an organometallic catalyst such as esters of manganese, copper, iron, cobalt, nickel or tin, or organic catalysts such as tertiary butyl peroxide. The result is a mixture of polar oxygenated compounds that can be divided into at least three categories: liquid, saponifiable and non-saponifiable.

The polar oxygen-containing compounds preferred according to the invention can be used in at least three ways are characterized by their molecular weight, their acid number and their saponification number. Chemically, these oxidation products are mixtures of acids, hydroxy acids, lactones, esters, ketones, alcohols, anhydrides and other oxygen-containing organic compounds. Compounds and mixtures with an average molecular weight between about 250 and 500, with an acid number between about 25 and 175 (ASTM-D-974), and a saponification number of about 30 to 250 (ASTM-D-974-52) are suitable for the present invention. Preferably, the polar oxygen-containing compounds used in the present invention have an acid number of about 50 to 100 and a saponification number of about 75 to 200. An example of a polar oxygen-containing hydrocarbon in this preferred range is ALOX 400L (Alox Corporation, Niagara Falls, New York).

Suitable compatibilizing substances for use in the fuel conditioning compound of the invention are organic compounds of moderate solubility and moderate to strong hydrogen bonding ability. Solubility parameters, 6, which are based on the cohesive energy density, are a fundamental characteristic of an organic solvent and provide a measure of its polarity. Simple aliphatic molecules of low polarity have a low 6 of about 7.3; highly polar water has a high 6 of 23.4. However, solubility parameters are only a first approximation of the polarity of an organic solvent. The dipole moment and the hydrogen bonding ability are also important for the general polarity and thus for the solvency. Symmetrical carbon tetrachloride and some aromatic compounds with a low dipole moment and low hydrogen bonding ability have a solubility parameter of about 8.5. In contrast, methyl propyl ketone has almost the same solubility parameter of 8.7, but a very strong Ability to form hydrogen bonds and a significant dipole moment. Consequently, no number describes the "polarity" of an organic solvent.

To practice the present invention, the compatibilizing substance should have a solubility parameter of about 8.8 to 11.5 and a moderate to strong ability to bond hydrogen. Suitable classes of organic solvents are alcohols, ketones, esters and ethers. Preferred compatibilizing substances are straight-chain, branched and alicyclic alcohols with 6 to 14 carbon atoms. Particularly preferred compatibilizing substances are hexanols, hectanols, octanols, nonyl alcohols, decanols and dodecanols.

The fuel conditioning compound according to the invention can additionally contain a hydrophilic separating agent which reduces the water content in the hydrocarbon-containing fuel and thus improves combustion. Suitable separating agents for carrying out the present invention are ethers of glycols or polyglycols, in particular monoethers. Monoethers are preferred over diethers when applying the invention.

Examples of such compounds that can be used are the monoethers of ethylene glycol, propylene glycol, trimethylene glycol, alpha-butylene glycol, 1,3-butanediol, beta-butylene glycol, isobutylene glycol, tetramethylene glycol, hexylene glycol, diethylene glycol, dipropylene glycol, tripropylene glycol, triethylene glycol, tetraethylene glycol, 1,5-pentanediol, 2-methyl-2-ethyl-1,3-propanediol, 2-ethyl-1,3-hexanediol. Some of these monoethers are ethylene glycol monophenyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-(n-butyl) ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-(n-butyl) Ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, diethylene glycol monocyclohexyl ether, ethylene glycol monobenzyl ether, triethylene glycol monophenyl ether, butylene glycol mono-(p-(n-butoxy) phenyl) ether, trimethylene glycol mono(alkylphenyl) ether, tripropylene glycol monomethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monoisobutyl ether, ethylene glycol monohexyl ether, triethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, 1-butoxyethoxy-2-propanol, the monophenyl ether of polypropylene glycol with an average molecular weight of about 975 to 1075, the monophenyl ether of polypropylene glycol, in which the polyglycol has an average molecular weight of about 400 to 450, the monophenyl ether of polypropylene glycol, in which the polypropylene glycol has an average molecular weight between 975 and 1075. These compounds are sold commercially under trade names such as Butyl CELLOSOLVE, Ethyl CELLOSOLVE, Hexyl CELLOSOLVE, Methyl CARBITOL, Butyl CARBITOL, DOWANOL Glycol Ether and similar designations.

In the practice of the present invention, it has been found useful to add aromatic hydrocarbons or a mixture thereof to the fuel conditioning compound of the present invention. Any aromatic hydrocarbon mixture which is liquid at room temperature is suitable. These include benzene, toluene, the three xylenes, trimethylbenzene, durene, ethylbenzene, cumene, biphenyl, dibenzyl and similar compounds or their mixtures. The preferred aromatic ingredient is a commercial mixture of the three xylenes because it is less expensive than any pure xylene. The word "xylene" as used in this specification and claims does not only mean the three specific xylenes o-xylene, m-xylene and p-xylene, but also includes aromatic fractions or distillates of aromatic hydrocarbons which include not only xylene but Benzene, toluene, durene and naphthol in admixture with the xylene. Aromatic naphtha is also useful. Without being bound by any theory or hypothesis for the use of aromatic hydrocarbons, it has been found that the presence of an aromatic hydrocarbon in the conditioning compound promotes clean and efficient combustion of the fuel.

The mixture according to the invention can additionally contain a suitable amount of a carrier oil or a liquefier selected from the group of petroleum oils, mineral oils, polypropylene compounds with a molecular weight in the range from 500 to 3,000, polyisobutylene compounds with a molecular weight in the range from 500 to 3,000, polyoxyalkylene compounds with a molecular weight in the range from 500 to 3,000, polybutyl and polyisobutyl alcohols containing polybutyl and polyisobutyl radicals derived from polyisobutene and up to 20% by weight of n-butene, the corresponding carboxylates of polybutyl or polyisobutyl alcohol or mixtures thereof. Petroleum oils that can be used include premium cylinder oils as well as both natural and synthetic, naphthenic and paraffinic oils of relatively high viscosity, including so-called solvent neutral oils (SNO) such as SNO-500 and SNO-600. Mineral oils that can be used include the so-called "light" mineral oils, e.g., the aliphatic and cyclic fractions of petroleum having a viscosity of less than 10,000 SUS at 25°C. A mixture of hydrocarbon fractions can also be used. The polybutyl and polyisobutyl alcohols described above include those disclosed in U.S. Patent No. 4,859,210 (Franz et al.). The terms "carrier oil" and "liquefier" used in this description and claims are interchangeable, which will be immediately understood by one skilled in the art.

Considering the many components described above, a large number of compositions are suitable for the additive of the invention. The following are a "useful range" and a "preferred range" in weight percent calculated on the total weight of the additive: Table 2 Component Useful range Preferred range Detergent Polar oxygenated compound Compatibilizing compound Hydrophilic release agent Aromatic hydrocarbon Carrier oil

The additive of the invention can be used in a wide variety of hydrocarbon-containing or modified hydrocarbon-containing (e.g. alcohol-containing) propellants for a variety of engines. Preferred motor fuel mixtures for use with the additive of the invention are those used in spark ignition internal combustion engines. Such motor fuels preferably contain a mixture of hydrocarbons which preferably boil between about 90 to 450 degrees Fahrenheit. This fuel can be made from straight chain or branched paraffins, cycloparaffins, olefins, aromatic hydrocarbons and their mixtures. The fuel may be derived from, among others, naphtha, polymeric gasoline, natural gasoline, catalytically or thermally cracked hydrocarbons or catalytically reformed gasoline. The fuel may also contain synthetic hydrocarbons, ethers such as methyl tertiary butyl ether (MTBE), ethyl tertiary butyl ether (ETBE) and similar ethers, alcohols such as methanol, ethanol, TBA and similar alcohols, and other functional organic compounds such as ketones, esters and similar compounds. The blend and octane number of the fuel are not critical and any conventional motor fuel may be used in the practice of this invention. Furthermore, the motor fuel blend may additionally contain other additives conventionally used in motor fuels (e.g. tetraethyl lead), antifreeze agents, cylinder head lubricating oils, carburetor detergents, anticorrosive additives, deemulsifying additives, odor reducers and similar additives.

Having described the invention in detail above, it will now be illustrated by the following examples. These examples, however, do not limit the application of this invention, which may also be carried out by other means in other systems.

example 1 (Comparison example)

Two automobiles (a Ford Escort and a Chevrolet Cavalier) were driven 7,000 miles on the same unleaded gasoline, containing no detergent additives (30% in the city, 70% on the highway), with an octane rating of 87. Before the test, the engines were disassembled and the combustion chambers completely cleaned.

After the 7,000 mile test drive, the engines were disassembled and the deposits that had accumulated in the intake valve and combustion chamber were collected and weighed. The results are summarized as follows: Car Model Ford Escort Chevrolet Cavalier Cylinder Injector Deposits in intake valve (g)* Deposits in combustion chamber (g)* * per unit

Example 2 (Comparison example)

The same test as in Example 1 was repeated, but this time each vehicle used an unleaded gasoline containing a different detergent additive blend at its recommended level. After 7,000 miles, the following results were obtained: Car Additive Deposits in the intake valve (g) Deposits in the combustion chamber

* Additive A 250 ppm of a polybutylsuccinimide additive*** + 500 ppm SNO 600.

** Additive B = 350 ppm of a polybutylamine additive*** + 600 ppm of a top cylinder oil.

*** Reaction product of a substituted hydrocarbon with an amine.

The above results show that although commercially available additives A and B improved intake valve cleanliness compared with Example 1, the deposit in the combustion chamber was increased, thereby unfavorably increasing the octane requirement increase (ORI).

Example 3 (Comparison example)

The same test as in Example 1 was conducted, but each vehicle used an unleaded gasoline containing 500 ppm of a fuel conditioning compound of the invention as described in U.S. Patent No. 4,753,661 and available from Polar Molecular Corporation (Saginaw, Mi.) under the trade name Duralt Fuel Conditioner.* The following results were obtained: Car Intake valve deposits (g) Combustion chamber deposits * Contained 30% (based on the weight of the fuel conditioning compound) of an active polar oxygen-containing compound.

Example 4 (Invention)

The same test was conducted as in Example 1, except that each vehicle used an unleaded gasoline containing the additives (A or B) as in Example 2 and in addition 500 ppm of the fuel conditioning compound of the invention available from Polar Molecular Corporation (Saginaw, Mi.) under the trade name Duralt Fuel Conditioner. The following results were obtained: Car Additive Deposits in the intake valve (g) Deposits in the combustion chamber DurAlt

The above results demonstrate that the additive of the invention in a fuel blend reduces both intake valve and combustion chamber deposits and therefore helps to reduce the Octane Demand Increase (ORI). These results are unexpected since the use of Additives A and B without the fuel conditioning agent DurAlt (see Example 2) showed much larger deposits (3 to 4 times larger) in the combustion chamber and consequently a larger Octane Demand Increase (ORI). Thus, the combination of the detergent and the fuel conditioning compound in the additive of the invention acts synergistically to reduce both intake valve and combustion chamber deposits.

Example 5 (According to the invention)

The same test was carried out as in Example 1, except that each vehicle used an unleaded gasoline containing the additives (A or B) as in Example 2 and, in addition, 300 ppm or 100 ppm of the fuel conditioning compound Duralt Fuel Conditioner. The following results were obtained: Car Additive Deposits in the intake valve (g) Deposits in the combustion chamber DurAlt

The above results again demonstrate that the additive of the invention in a motor fuel reduces both intake valve and combustion chamber deposits and, consequently, octane requirement increase (ORI). These results are again unexpected because when additives A and B were used without the fuel conditioning compound Duralt (see Example 2), much larger (2 to 3 times larger) combustion chamber deposits and, consequently, a higher octane requirement increase (ORI) occurred. Thus, the combination of detergent and fuel conditioning compound in the additive of the invention acts synergistically to reduce both intake valve and combustion chamber deposits.

Example 6 (Comparison example)

The same test as in Example 1 was conducted on Car #2, except that Car #2 used unleaded gasoline with Additive Blend B and an additional 500 ppm of a commercially available additive, namely a poly(oxyethylene) (oxypropylene) polyol described in U.S. Patent No. 4,548,616 (Sung et al.). These additives are available from BASF Wyandotte Corporation under the PLURONIC series of trade names. The following results were obtained: Car Additive Intake valve deposits (g) Combustion chamber deposits PLURONIC L-31 * PLURONIC L-31, a product of BASF Wyandotte Corporation, is a poly(oxyethylene)-poly(oxypropylene)-poly(oxyethylene) polyol having a molecular weight of about 950, in which about 10 wt. % is derived from poly(oxyethylene) and about 90 wt. % is derived from poly(oxypropylene).

The above results show that a combination of the additive mixture B, added to the poly(oxyethylene)(oxypropylene) polyol (PLURONIC L-31), affects the deposits in the combustion chamber and thus the octane requirement increase (ORI) of the engine less effectively than the additive according to the invention, as shown in Examples 4 and 5.

Example 7 (According to the invention)

Knocking problems were observed in a Honda Accord having a 1-4 engine with a 2-barrel carburetor and 64,550 miles of mileage that had been run primarily on unleaded gasoline with commercial additives. This car was then run for 2,000 miles on a fuel containing the additive of the invention, namely an additive blend of Additive B as described in Example 2 (350 ppm of the polybutylamine additive and 600 ppm of a top cylinder oil) and 500 ppm Duralt FC. The knocking problems completely disappeared, demonstrating a clear reduction in the Octane Demand Increase (ORI) for this vehicle. This example illustrates the utility of the invention in so-called "clean-up" applications where use of the invention improves the performance of engines that have already demonstrated an Octane Demand Increase (ORI).

Additional test results were obtained using an E56500 Honda engine test system. Two identical engine systems with equal loading (electrical resistance of 1,500 and 2,500 watt hot water appliances) were used according to the test procedure described by M. Megnin et al., "Development of a Gasoline Additive screening Test for Intake Valve Stickiness and Deposit Levels," SAE Paper No. 892121 (presented at the International Fuels and Lubricants Meeting, Baltimore, Md. Sept. 1989), but modified as follows:

In preparation for the test, the engine was first disassembled. The intake valve was then cleaned with a rubber solvent consisting of a mixture of 1/3 acetone, 1/3 toluene and 1/3 methanol to remove any lubricating oil from the valves. The valves were then stored in a dryer for at least one hour and then weighed to the nearest 0.1 mg immediately before reassembly of the engine. The combustion chambers and their openings were cleaned with a suitable wire brush. The cleaned cylinder heads were reassembled and fitted into the engine and the rest of the machine was then reassembled. The oil and oil filter were replaced before testing.

The fuel mixture to be tested was prepared and added to the fuel tank. The engine was started and idle for 30 seconds to warm up. The engine was then run at a load of 1,500 watts for two hours. After two hours, the generator load, coolant inlet and outlet temperatures, oil temperature, exhaust temperatures for cylinders 1 and 2, and manifold vacuum were recorded. The engine was then run for an additional two hours at a load of 2,500 watts. After these two hours, the data described above were again recorded. The four-hour test run described above was carried out (interrupted by refueling) for 16 hours per day for five consecutive days, for a total of 80 hours. After the 80 hours, the gasoline tank was drained and the gasoline added to the remaining test mixture intended for the experimental run. The total volume of remaining fuel was measured to calculate fuel consumption during the 80-hour test run.

After completing the 80-hour test run, the was disassembled, including the removal of the cylinder head, camshaft and rocker arm assembly. The amount of deposits on the intake system consisting of the carburetor throttle body, manifold inlet and Intake valves were determined using the procedure described in the Coordination Research Council (CRC) Rating Manual No. 16, Atlanta, Ga. 1987 ("CRC Rating"), which is well known to those skilled in the art. Deposits in the combustion chamber and on the tops of the pistons were similarly determined using the CRC Rating System. The order for determination, weighing of the valves, and taking photographs was as follows: The tops of the pistons, cylinder head, combustion chamber, manifold inlet, and throttle valve were all initially determined and photographed. The side of the intake valves facing the combustion chamber was then cleaned and then the intake valves were carefully removed so as not to disturb the deposits deposited thereon. The valve stems were wiped with rubber solvent to remove lubricating oil and then photographed. The valves were then placed in a dryer for one hour, then removed and immediately weighed, the weight being determined to the nearest 0.1 mg. The valves were then returned to the dryer and weighed again after another half hour. This procedure was repeated until the weights of the valves were within 0.5 mg. The valves were then cleaned with the rubber solvent and a wire brush and kept in the dryer until final weighing. The engine was then reassembled with a new set of intake valves and the engine runs repeated.

A fuel blend obtained from Sun Refining and Marketing Company was used in all of the following examples. Analysis of the fuel blend revealed the following: Measured value Result API Weight, ASTM D287 Research Octane Number R, ASTM D2699 Motor Octane Number M, ASTM D2700 Sensitivity (RM) Octane Number (R+M/2) Reid Vapor Pressure, psi ASTM D323 automated Distillation, ASTM D86 automated Initial Boiling Point 10% evaporated Final Boiling Point Hydrocarbon Composition Vol.%, ASTM D1319 Aromatics Olefins Saturated Hydrocarbons

The fuel mixture was tested without any additives in both Honda engine systems to obtain comparative results. Both intake valve deposit weights (in mg) and combustion chamber ratings were obtained according to the CRC procedure described above for the two engines as follows:

Example 8 (Comparison example)

A variety of fuel blends, including fuel blends containing the additive of the invention, were tested in Honda engines using the above procedure to obtain intake valve deposit measurements and combustion chamber ratings. These test results are summarized below:

Example 9

Motor fuel blends were prepared using Sun Refining and Marketing Company’s fuel blend with the addition of the following additives: Fuel Detergent (250 mg/l fuel) Fuel Conditioner* Carrier Oil (Comparative) (Invention) Polyisobutylamine Isooctylphenylpolyethoxyethanol yes * In fuels No. I-VII, 250 mg of a 1:1 mixture of SNO-600 oil and synthetic oil was used as carrier oil ** The fuel conditioner was 100 mg/l fuel of a polar oxygenated hydrocarbon plus 40 ppm of a compatibilizing compound (hexanol).

Fuels I-VII were classified according to the amount of deposits in the intake valve (in mg) and according to the method of combustion chamber evaluation (CRC), as summarized in Fig. 1. As is clear from Fig. 2, in which the data from Fig. 1 are plotted, fuel blends Nos. III, V and VII (ie fuel blends with the additive according to the invention) showed superior properties both in terms of combustion chamber evaluation (ie high CRC ratings) and a reduction of deposits in the intake valve (ie low values of deposits in mg in the intake valves).

It is to be understood that the terms and expressions used herein are for the purpose of description and not of limitation. In using these descriptive terms and expressions, it is not intended to exclude equivalents of the described acts, and it is recognized that various modifications are possible within the scope of the claimed invention.

Claims (18)

1. Additive for motor fuel containing a mixture of : (a) 5-50% by weight, based on the total weight of the additive of a detergent selected from the group consisting of : (i) a reaction product of: (A) a substituted hydrocarbon of the formula R1 - X (I) wherein R₁ is a hydrocarbon radical having a molecular weight in the range of 150-10,000 and X is selected from the group consisting of halogens, succinic anhydride and dibasic succinic acid, and (B) an amine of the formula H - (NH - (A)m)n - Y - R₂ (II) in which Y is 0 or NR₅ and R₅ is H or a hydrocarbon radical having 1-30 carbon atoms; A is a straight-chain or branched alkylene radical having 1-30 carbon atoms; m has a value in the range of 1-15; n has a value in the range of 0-6; and R₂ is selected from the group consisting of H, a hydrocarbon radical having a molecular weight in the range of 15-10,000, and a 1-30 homopolymeric or heteropolymeric polyoxyalkylene radical of the formula R3; - ((Q)a(T)b(Z)c)d - (III) where R₃ is H or a hydrocarbon radical having 1-30 carbon atoms, Q, T and Z are polyoxyalkylene radicals having 1-6 carbon atoms a, b and c each have values between 0 and 30 and d has a value in the range between 1 and 50, and (ii) a polybutylamine or polyisobutylamine of the formula in which R₁₁ is a polybutyl or polyisobutyl radical derived from isobutene and up to 20% by weight of n-butene, and R₁₂ and R₁₃ are the same or different and each represents hydrogen, an aliphatic or aromatic hydrocarbon radical, a primary or secondary, aromatic or aliphatic aminoalkylene or polyaminoalkylene radical, a polyoxyalkylene, a heteroaryl or heterocyclyl radical, or together with the nitrogen atom to which they are attached; form a ring in which further heteroatoms may be present; and (b) a fuel conditioning compound containing: (i) 2-50% by weight, based on the total weight of the additive, of a polar, oxygen-containing hydrocarbon having an average molecular weight in the range between 250-500, an acid number in the range between 25-175, and a saponification number in the range of about 30-250 and (ii) 2-50% by weight, based on the total weight of the additive, of an oxygen-containing compatibilizing compound having a solubility parameter in the range of about 8.8-11.5 and a moderate to strong hydrogen bonding ability. 2. Additive according to claim 1, in which the molar ratio of the substituted hydrocarbon R₁-X to the amine is in the range between 0.2:1 to 20:1. 3. Additive according to claim 1, wherein R₁-X is a chloropolyisobutylene or a polyisobutylene succinic anhydride. 4. Additive according to claim 1, in which R₂ is selected from the group consisting of hydrogen, a hydrocarbon radical having a molecular weight in the range of 15-2000, and a polyoxyalkylene radical of the formula (III) in which R₃ is H or a hydrocarbon radical having 1-22 carbon atoms, Q, T and Z are polyoxyalkylene moieties having 1-6 carbon atoms, a, b, c and d have values in the range of 1-25, Y is O or NR₅, where R₅ is H or a hydrocarbon radical having 1-22 carbon atoms, A is a straight-chain or branched alkylene radical having 1-15 carbon atoms, m has a value in the range between 1-12 and n has a value in the range between and 5. 5. Additive according to claim 1, wherein the amine of formula (II) is selected from the group consisting of polyethylenepolyamines, polypropylenepolyamines and their mixtures. 6. Additive according to claim 1, wherein the compatibilizing compound is an alcohol containing three or more carbon atoms. 7. Additive according to claim 1, wherein the fuel conditioning compound additionally contains 0-40 wt.%, based on the total weight of the additive, of a hydrophilic release agent. 8. Additive according to claim 1, wherein the fuel conditioning compound additionally contains 0-80 wt.%, based based on the total weight of the additive, of an aromatic hydrocarbon. 9. Additive according to claim 1, which additionally contains 0-80% by weight, based on the total weight of the additive, of a carrier oil selected from the group of oils derived from petroleum, mineral oils, polypropylene compounds with a molecular weight in the range between 500 and 3000, polyisobutylene compounds with a molecular weight in the range of 500- 3000, polyoxyalkylene compounds with a molecular weight in the range of 500-3000, and polybutyl and polyisobutyl alcohols which contain polybutyl or polyisobutyl radicals which are derived from polyisobutene and up to 20% by weight of n-butene, as well as corresponding carboxylates of polybutyl or isobutyl alcohol and mixtures thereof. 10. A process for preparing an additive compound for motor fuels, which comprises mixing: (a) 5-50% by weight, based on the total weight of the additive, of a detergent selected from the group consisting of : (i) the reaction product of: (A) a substituted hydrocarbon of the formula R1 - X (I) in which R₁ is a hydrocarbon radical having a molecular weight in the range between 150 and 10,000 and X is selected from the group consisting of halogens, succinic anhydride and dibasic succinic acid, and (B) an amine of the formula H - (NH - (A)m)n - Y - R₂ (II) in which YO or NR₅, where R₅ is H or a hydrocarbon radical having 1-30 carbon atoms; A is a straight-chain or branched alkylene radical having 1-30 carbon atoms; m has a value in the range between 1-15; n has a value in the range between 0-6; and R₂ is selected from the group consisting of hydrogen, a hydrocarbon radical having a molecular weight in the range of 15-10,000 and a homopolymeric or heteropolymeric polyoxyalkylene radical of the formula R3; - ((Q)a(T)b(Z)c)d - (III) in which R₃ is H or a hydrocarbon radical with 1-30 carbon atoms, Q, T and Z polyoxyalkylene radicals with 1-6 carbon atoms, a, b and c each have values between 0-30 and d have a value between 1-50 and (ii) a polybutylamine or polyisobutylamine of the formula in which R₁₁ is a polybutyl or polyisobutyl radical derived from isobutene and up to 20% by weight of n-butene and R₁₂ and R₁₃ are the same or different and are each hydrogen, an aliphatic or aromatic hydrocarbon, a primary or secondary, aromatic or aliphatic aminoalkylene radical or polyaminoalkylene radical, a polyoxyalkylene radical or a heteroaryl or heterocyclyl radical, or together with the nitrogen atom to which they are attached form a ring in which further heteroatoms may be present; and (b) a fuel conditioning compound containing: (i) 2-50% by weight, based on the total weight of the additive, of a polar, oxygen-containing hydrocarbon having an average molecular weight in the range of 250-500, an acid number in the range of 25-175 and a saponification number in the range of about 30-250 and (ii) 2-50% by weight, based on the total weight of the additive, of an oxygen-containing, compatibilizing compound having a solubility parameter in the range of about 8.8-11.5 and moderate to strong hydrogen-binding ability. 11. The process of claim 10 wherein the molar ratio of the substituted hydrocarbon R1-X to the amine is in the range of 0.2:1 to 20:1. 12. A process according to claim 10, in which R₁-X is a chloropolyisobutylene or a polyisobutene succinic anhydride . 13. A process according to claim 10, in which R₂ is selected from the group consisting of H, a hydrocarbon radical having a molecular weight in the range between 15-2000, and a polyoxyalkylene radical of the formula (III) in which R₃ is H or a hydrocarbon radical having 1-22 carbon atoms, Q, T and Z are polyoxyalkylene radicals having 1-6 carbon atoms, a, b, c and d are values between 1-25, Y is 0 or NR₅, where R₅ is H or a hydrocarbon radical having 1-22 carbon atoms, A is a straight-chain or branched alkylene radical having 1-15 carbon atoms, m has a value between 1-12 and n has a value between 0-5. 14. The process according to claim 10, wherein the amine of formula (II) is selected from the group consisting of polyethylenepolyamines, polypropylenepolyamines and mixtures thereof. 15. A process according to claim 10, in which the compatibilizing compound is an alcohol having three or more carbon atoms. 16. A method according to claim 10, in which the fuel conditioning compound additionally contains 0-40 wt.%, based on the total weight of the additive, of a hydrophilic release agent. 17. A method according to claim 10, in which the fuel conditioning compound additionally contains 0-80% by weight, based on the total weight of the additive, of an aromatic hydrocarbon. 18. The method according to claim 10, in which the reaction product and the fuel conditioning compounds are additionally mixed with 0-80% by weight, based on the total weight of the additive, of a carrier oil which is selected from the group consisting of petroleum-derived oils, mineral oils, polypropylene compounds with a molecular weight in the range between 500-3000, polyisobutylene compounds with a molecular weight in the range between 500-3000, polyoxyalkylene compounds with a molecular weight in the range between 500-3000, and polybutyl and polyisobutyl alcohols which contain polybutyl or polyisobutyl radicals which are derived from polyisobutene and up to 20% by weight from n-butene, corresponding carboxylates of polybutyl or polyisobutyl alcohol and mixtures thereof.