EP0303351B1

EP0303351B1 - Deposit-resistant motor fuel composition containing an additive which lowers the use of octane boosters

Info

Publication number: EP0303351B1
Application number: EP19880306166
Authority: EP
Inventors: Rodney Lu-Dai Sung; Milton Daniel Behrens; Michael Angelo Caggiano; John Frederick Knifton; John Michael Larkin; Robert Leroy Zimmerman; Thomas Hayden
Original assignee: Texaco Development Corp
Current assignee: Texaco Development Corp
Priority date: 1987-08-12
Filing date: 1988-07-06
Publication date: 1991-06-19
Also published as: EP0303351A1; JPS6466293A; JP2613271B2; DE3863325D1

Description

This invention relates to a gasoline-soluble reaction product, to a concentrate comprising the reaction product dissolved in a hydrocarbon solvent, and to a haze-free, deposit resistant and ORI-inhibited motor fuel composition comprising the reaction product.
Combustion of a hydrocarbon and hydrocarbonceous motorfuel in an internal combustion engine generally results in the formation and accumulation of deposits on various parts of the combustion chamber as well as on the fuel intake and exhaust systems of the engine. The presence of deposits in the combustion chamber seriously reduces the operating efficiency of the engine. First, deposit accumulation within the combustion chamber inhibits heat transfer between the chamber and the engine cooling system. This leads to higher temperatures within the combustion chamber, resulting in increases in the end gas temperature of the incoming charge. Consequently, end gas auto-ignition occurs, which causes engine knock. In addition, the accumulation of deposits within the combustion chamber reduces the volume of the combustion zone, causing a higher than design compression ratio in the engine. This, in turn also results in serious engine knocking. A knocking engine does not effectively utilize the energy of combustion. More over, a prolonged period of engine knocking will cause stress fatigue and wear in vital parts of the engine. The above-described phenomenon is characteristic of gasoline powered internal combustion engines. It is usually overcome by employing a higher octane gasoline for powering the engine, and hence has become known as the engine octane requirement increase (ORI)phenomenon. It would therefore be highly advantageous if engine ORI could be substantially reduced or eliminated by preventing or modifying deposit formation in the combustion chambers of the engine.
Another problem common to internal combustion engines relates to the accumulation of deposits in the carburetor which tend to restrict the flow of air through the carburetor at idle and at low speed, resulting in an overrich fuel mixture. This condition also promotes incomplete fuel combustion and leads to rough engine idling and engine stalling. Excessive hydrocarbon and carbon monoxide exhaust emissions are also produced under these conditions. It would therefore be desirable from the standpoint of engine operability and overall air quality to provide a motor fuel composition which minimizes or overcomes the above-described problems.
A third problem common to internal combustion engines is the formation of intake valve deposits. Intake valve deposits interfere with valve closing and eventually result in valve burning. Such deposits interfere with valve motion and valve sealing, and in addition reduce volumetric efficiency of the engine and limit maximum power. Valve deposits are usually a result of thermal and oxidative unstable fuel or lubricating oil oxidation products. Hard carbonaceous deposits collect in the tubes and runners that conduct the exhaust gas recirculation (EGR) gases. These deposits are believed to be formed from exhaust particles which are subjected to rapid cooling while mixing with the air-fuel mixture. Reduced EGR flow can result in engine knock and NO_X emission increases. It would therefore be desirable to provide a motor fuel composition which minimizes or overcomes the formation of intake valve deposits.
Deposit-inhibiting additives for use in motor fuel compositions are well known in the art. For example :
Co-assigned U.S. Pat. Appl. Serial No. 000,253, filed January 2, 1987, (D # 78,650) (Sung et al.) discloses a novel polyoxyalkylene diamine compound of the formula:
where c has a value from about 5-150, b + d has a value from about 5-150, and a + e has a value from about 2-12. Motor fuel compositions comprising the novel polyoxyalkylene diamine, alone or in combination with a polymer/copolymer additive are also disclosed.
Co-assigned U.S. 4,689,031 (Sung) discloses an additive composition useful in improving the storage stability of middle distillate fuel oils, the additive prepared by reacting (i) a hydrocarbon-substituted mono primary amine or a hydrocarbon-substituted mono primary ether amine, (ii) a dibasic acid anhydride, and (iii) an N-alkyl alkylene diamine.
Co-assigned U.S. 4,581,040 (Sung et al.) teaches the use of a reaction product as a deposit inhibitor additive in fuel compositions. The reaction product taught is a condensate product of the process comprising : (i) reacting a dibasic acid anhydride with a polyoxyisopropylenediamine thereby forming a maleamic acid ; (ii) reacting the maleamic acid with a polyalkylene polyamine, thereby forming a condensate product ; and (iii) recovering the condensate product.
Co-assigned US. 4,659,336 (Sung et al.) discloses the use of the mixture of : (i) the reaction product of maleic anhydride, a polyether polyamine containing oxyethylene and oxypropylene ether moieties, and a hydrocarbyl polyamine ; and (ii) a polyolefin polymer/copolymer as an additive in motor fuel compositions to reduce engine ORI.
Co-assigned U.S. 4,659,337 (Sung et al.) discloses the use of the reaction product of maleic anhydride, a polyether polyamine containing oxyethylene and oxypropylene ether moieties, and a hydrocarbyl polyamine in a gasoline motor fuel to reduce engine ORI and provide carburetor detergency.
Co-assigned U.S. 4,643,738 (Sung et al.) discloses a motor fuel additiye useful in reducing combustion chamber deposits, the additive prepared by reacting a dibasic acid anhydride, a polyoxyisopropylene diamine, and an N-alkyl-alkylene diamine.
Co-assigned U.S. 4,643,737 (Sung et al.) discloses a motor fuel additive useful in reducing combustion chamber deposits, the additive prepared by reacting maleic anhydride, an alpha-hydroxy omega-hydroxy-poly(oxyethylene) poly(oxypropylene) poly(oxyethylene) block copolymer, and an N-alkyl-alkylene diamine.
Co-assigned U.S. 4,631,069 (Sung) discloses a wear-inhibiting additive for use in alcohol fuel compositions, the additive prepared by reacting a polyoxyisopropylene diamine, a dibasic acid anhydride, and an N-alkyl-alkylene diamine.
U.S. 4,604,103 (Campbell) discloses a motor fuel deposit control additive for use in internal combustion engines which maintains cleanliness of the engine intake system without contributing to combustion chamber deposits or engine octane requirement increase (ORI). The additive disclosed is a hydrocarbyl polyoxyalkylene polyamine ethane of molecular weight range 300-2500 having the formula
where R is a hydrocarbyl radical of from 1 to about 30 carbon atoms ; R' is selected from methyl and ethyl ; x is an integer from 5 to 30 ; and R" and R"' are independently selected from hydrogen and -(CH₂CH₂NH-)y H where y is an integer from 0-5.
U.S. 4,357,148 (Graiff) discloses a motor fuel additive useful in controlling ORI which is the combination of (a) an oil-soluble aliphatic polyamine containing at least one olefinic polymer chain, and (b) a polymer, copolymer, or corresponding hydrogenated polymer or copolymer of a C₂-C_e mono olefin with a molecular weight of 500-1500.
U.S. 4,166,726 (Harle) discloses a fuel additive which is the combination of (i) the reaction product of an alkylphenol, an aldehyde, and an amine, and (ii) a polyalkylene amine.
U.S. 3,960,515 (Honnen) and U.S. 3,898,056 (Honnen) disclose the use of a mixture of high and low molecular weight hydrocarbyl amines as a detergent and dispersant in motor fuel compositions.
U.S. 3,438,757 (Honnen et al.) discloses the use of hydrocarbyl amines and polyamines with a molecular weight range of 450-10,000, alone or in combination with a lubricating mineral oil, as a detergent for motor fuel compositions.
It is one object of this invention to provide a gasoline-soluble reaction product additive for use in motor fuel compositions. It is another object of this invention to provide a concentrate composition comprising the reaction product additive dissolved in a hydrocarbon solvent. It is yet another object of this invention to provide a haze-free, deposit resistant and ORI-inhibited motor fuel composition comprising the reaction product as well as a hydrocarbon solvent based concentrate composition which may be added to motor fuel to produce such a motor fuel composition.
It is one advantage of this invention that motor fuel compositions of the instant invention are haze-free, ORI-inhibited, and deposit-resistant. It is another advantage of this invention that the reaction product additive of the instant invention is soluble in gasoline and similar motor fuel compositions, and therefore requires no admixing with a solvent prior to introduction into a base motor fuel composition.
The invention provides a motor fuel composition exhibiting both reduced ORI and increased resistance to carburetor intake valve, intake manifold, and EGR system deposit formation in comparison with conventional motor fuel compositions.
Motor fuel compositions of the instant invention show improved ORI-inhibition and carburetor and valve deposit resistance over conventional motor fuel compositions. Motor fuel compositions of the instant invention comprise a mixture of hydrocarbons boiling in the range 30 to 230°C (90°F-450°F) and additionally comprise:

(I) from 0.0005-5.0 weight percent of the reaction product obtained by reacting a temperature of 30°C-200°C:
- (a) 1 mole of a dibasic acid anhydride of the formula
  where each R₁ is H or C₁-C₅ alkyl,
- (b) 1-2 moles of a polyoxyalkylene diamine of the formula
  where R₅ and R₈ are C₁-C₁₂ alkylene groups, q and r are 0 or 1, c is 5-150, b + d is 5-150, and a +
  - e is 2-12 ; and
- (c) 1-2 moles of a hydrocarbyl polyamine which may be either
  - (i) a hydrocarbyl polyamine of the formula
    where R₂ is alkyl having 1-24 carbon atoms, R₃ is an alkylene radical having 1-6 carbon atoms, and x 1-10, or
  - (ii) a N-alkyl-alkylene diamine of the formula
    where R₄ is an aliphatic hydrocarbon radical having 1-24 carbon atoms and n 1-6 ; and
(II) from 0.001-1.0 weight percent of a mixture comprising a hydrocarbon solvent and :
- (a) 50-75 parts by weight of polyisobutylene ethylene diamine of the formula
  and
- (b) 5-25 parts by weight of polyisobutylene of the formula
  where z is 30-40.

The instant invention is also directed to a concentrate comprising a hydrocarbon solvent in admixture with 0.1-10.0 weight percent of the abovedescribed reaction product component and 25.0-75.0 weight percent of, the abovedescribed hydrocarbon solvent-polyisobutylene ethylene diamine-polyisobutylene mixture.
Referring now to the drawings, Figure 1 is a graphical representation of data obtained which compares the octane requirement (as a function of hours of engine operation) of a Chevrolet 1.8 liter engine using an commercial unleaded base fuel containing 191.2 g/m³ (60PTB) of a commercial fuel additive, and the identical engine using a motorfuel composition of the instant invention as exemplified by Example IV. Figure 2 is a graphical representation of data obtained which compares the octane requirement (as a function of hours of engine operation) of a Chevrolet 2.0 liter engine using a commercial, gasoline, and the identical engine using a motor fuel composition of the instant invention as exemplified by Example IV.
Component (I) of the instant invention is a reaction product prepared by reacting a dibasic acid anhydride, a diamine containing block copolymers with polyoxyalkylene backbones, and a hydrocarbyl polyamine. The reaction product component of the instant invention is identical to the reaction product disclosed in U.S. Pat. Appl. Serial No. 000,230 corresponding to EP-A-0273545.
The dibasic acid anhydride reactant used to prepare the reaction product component of the instant invention is of the formula
where R₁ is either H or a C₁-C₅ alkyl radical. Accordingly, dibasic acid anhydrides suitable for use include maleic anhydride ; alpha-methyl maleic anhydride ; alpha-ethyl maleic anhydride ; and alpha, beta-dimethyl maleic anhydride. The preferred dibasic acid anhydride for use is maleic anhydride.
The polyoxyalkylene diamine reactant has the formula
where R₅ and R₆ are C₁-C₁₂ alkylene, and q and r are 0 or 1.
The preferred polyoxyalkylene diamine reactant used to prepare the reaction product component of the instant invention is a diamine of the formula
where c is 5-150, preferably 8-50 ; b + d is 5-150, preferably 8-50 ; and a + e is 2-12, preferably 4-8. The novelty of the prescribed polyoxyalkylene diamine reactant resides in the fact that it contains a large number (5-150, preferably 8-50) of polyoxypropylene and polyoxyethylene ether moieties in combination with a smaller number (2-12, preferably 4-8) of polyoxybutylene ether moieties. The method of synthesis of the prescribed novel polyoxyalkylene diamine reactant is setforth in detail in U.S. Pat. Appl. Serial No. 000,253 (corresponding EP-A-0273545).
The hydrocarbyl polyamine reactant used to prepare the reaction product component of the instant invention may be either :

(i) a hydrocarbyl polyamine of the formula
where R₂ is alkyl having from 1-24, preferably 12-20 carbon atoms, R₃ is alkylene having from 1-6 carbon atoms, and x is 1-10, preferably 1-5 ; or
(ii) a N-alkyl-alkylene diamine of the formula
where R₄ is an aliphatic hydrocarbon radical having 1 to 24 carbon atoms, preferably 12 to 20 carbon atoms, and n is 1-10, preferably 1 to 6, most preferably 3. N-alkyl-alkylene diamines suitable for use in preparing the reaction product used in the instant invention include aliphatic diamines commercially available from Akzo Chemie America Co. under the DUOMEEN series trade name. Examples of such N-alkyl-alkylene diamines include N-coco-1,3-diamino-propane (DUOMEEN C), N-soya-1,3-diaminopropane (DUOMEEN S), N-tallow-1,3-diaminopropane (DUOMEEN T), and N-oleyl-1,3-diaminopropane (DUOMEEN OL). The most preferred N-alkyl-alkylene diamine reactant for use in preparing the reaction product component used in the instant invention is N-tallow-1,3 diaminopropane.

The reaction product component (I) used in the instant invention is prepared by first reacting 1 mole of dibasic acid anhydride with 1 to 2 moles, preferably 1.5 moles of the prescribed diamine reactant containing block copolymers with polyoxyethylene, polyoxypropylene and polyoxybutylene backbones at a temperature of30°C-200°C, preferably 90°C-150°C. The reaction of dibasic acid anhydride with the polyoxyalkylene diamine reactant is preferably carried out in the presence of a solvent. A preferred solvent is one which will distill with water azeotropically. Suitable solvents include hydrocarbons boiling in the gasoline boiling range of 30°C to 200°C. Generally, this will include saturated and unsaturated hydrocarbons having from 5 to 10 carbon atoms. Specific suitable hydrocarbons solvents include hexane, cyclohexane, benzene, toluene, and mixtures thereof. Xylene is the preferred solvent. The solvent can be present in an amount of up to 90% by weight of the total reaction mixture. The reaction mixture is thereafter cooled to 50°C-75°C, preferably 60°C, and 1-2 moles, preferably 1 mole of the hydrocarbyl polyamine is added. The new mixture is then reacted at 30°C-200°C, preferably 90°C-150°C.
In a preferred mode of preparing the reactoin product component of the instant invention, 1 mole of maleic anhydride and 1.5 moles of the prescribed polyoxyalkylene diamine where c is 8-50, b + d is 8-50, and a + e is 4-8 are combined with the solvent xylene and reacted at a temperature of 100°C. The reaction mixture is maintained at this temperature for approximately 2 hours. The mixture is then cooled to 60°C, whereupon 1 mole of the hydrocarbyl polyamine N-tallow-1,3 diaminopropane is added. The new mixture is then reacted at 140°C for reflux and azeotroping for 5 hours, with about 1 to 1.5 moles of water being removed. The reaction product can then be separated from the solvent using conventional means, or left in admixture with some or all of the solvent.
A critical feature of the reaction product component of the instant invention is the presence of a large number (5-150, preferably 8-50) of polyoxypropylene and polyoxyethylene ether moieties in combination with more limited numbers (2-12, preferably 4-8) of polyoxybutylene ether moieties. These moieties are provided by the prescribed polyoxyalkylene diamine reactant. In particular, the presence of a large number of polyoxypropylene and polyoxyethylene ether moieties enhances the gasoline solubility of the reaction product component, thus increasing the efficacy of the reaction product as an additive in motor fuel compositions. The reaction product component of the instant invention is advantageous over other reaction product additives employed to control ORI in motor fuels such as those disclosed in US-A-4659336 and -4659337 in that the reaction product component used in the instant invention is soluble in gasoline and similar motor fuel compositions, and therefore requires no admixing with a solvent prior to introduction into a base motor fuel composition.
The following examples illustrate the preferred method of preparing the novel reaction product component of the instant invention. In the examples, all parts are parts by weight unless otherwise specified.

Example I

In the best mode for preparing the reaction product component of the instant invention, 54 parts of maleic anhydride, 3265 parts of xylene, and 3000 parts of a polyoxyalkylene diamine were reacted at a temperature of 100°C for 2 hours. The polyoxyalkylene diamine was of the formula
where c had an approximate value of 5-150, b + d had an approximate value of 5-150, and a + e had an approximate value of 2-12.
The mixture was thereafter cooled to about 60°C, and 54 parts of N-tallow-1,3 diaminopropane (DUOMEEN T) were added. The new mixture was then reacted at about 140°C for 5 hours to produce the final reaction product. The final reaction product was then filtered and stripped of remaining solvent under vacuum.

Example 11

A reaction product is formed by reacting 54 parts of maleic anhydride, 3206 parts of xylene, and 3000 parts of a polyoxyalkylene diamine at 100°C for 2 hours. The polyoxyalkylene diamine is of the formula
where c has an approximate value of 5-150, b + d has an approximate value of 2-12.
The mixture is thereafter cooled to about 60°C, and 152 parts of N-coco-1,2 diaminopropane (DUOMEEN C) are added. The new mixture is then reacted at about 140°C for 5 hours to produce the final reaction product. The final reaction product is then filtered and stripped of remaining solvent under vacuum.

Example III

A reaction product is formed by reacting 54 parts of maleic anhydride, 3231 parts of xylene, and 3000 parts of a polyoxyalkylene diamine at 100°C for 2 hours. The polyoxyalkylene diamine is of the formula
where c has an approximate value of 5-150, b + d has an approximate value of 5-150, and a + e has an approximate value of 2-12.
The mixture is thereafter cooled to about 60°C, and 176 parts of N-oleyl-1,3 diaminopropane (DUOMEEN OL) are added. The new mixture is then reacted at about 140°C for 5 hours to produce the final reaction product. The final reaction product is then filtered and stripped of remaining solvent under vacuum.
Component (II) of the motor fuel composition of the instant invention is a mixture of a major amount of polyisobutylene ethylene diamine and a minor amount of polyisobutylene. These subcomponents will usually be employed in admixture with a hydrocarbon solvent to facilitate addition of Component (II) to a base motor fuel composition.
The polyisobutylene ethylene diamine subcomponent of Component (II) of the instant invention is typically present in a concentration range of 50-75 parts, preferably about 60 parts by weight, based upon the weight of the entire composition which makes up Component (II). The polyisobutylene ethylene diamine subcomponent is of the formula
where z has a value of 30-40, preferably 32-35, most preferably 33.
The polyisobutylene subcomponent of Component (II) of the instant invention is typically present in a concentration range of 5-25 parts, preferably 10-20 parts by weight, based upon the weight of the entire composition which makes up Component (II). The polyisobutylene subcomponent is of the formula
where z again has a value of 30-40, preferably 32-35, most preferably 33.
The hydrocarbon solvent employed to facilitate admixture of the abovedescribed subcomponents is preferably a light aromatic distillate composition. A commercially available light aromatic distillate composition containing the abovedescribed polyisobutylene ethylene diamine and polyisobutylene compounds in the abovespecified concentrations and particularly preferred for use as Component (II) of the instant invention is the commercial gasoline additive ORONITE OGA-472, available from Chevron Chemical Company. ORONITE OGA-472 is a composition containing approximately 60 parts by weight of polyisobutylene ethylene diamine, approximately 13 parts by weight polyisobutylene, and approximately 27 parts by weight light aromatic distillate, including xylene and Cg alkylbenzenes. Fuel compositions containing ORONITE OGA 472 as an additive include those described in US-A-4141693, -4028065 and -3966429.
The motor fuel composition of the instant invention comprises a major amount of a base motor fuel and 0.0005-5.0 weight percent, preferably 0.001-1.0 weight percent of Component (I) (the abovedescribed reaction product component) and 0.001-1.0 weight percent, preferably 0.01-0.5 weight percent of Component (II), (the abovedescribed mixture comprising a major amount of polyisobutylene ethylene diamine and a minor amount of polyisobutylene in a hydrocarbon solvent). Preferred base motor fuel compositions are those intented for use in spark ignition internal combustion engines. Such motor fuel compositions, generally referred to as gasoline base stocks, comprise a mixture of hydrocarbons boiling in the gasoline boiling range from 30 to 230°C (90°F to 450°F). This base fuel may consist of straight chains or branched chains or paraffins, cycloparaffins, olefins, aromatic hydrocarbons, or mixtures thereof. The base fuel can be derived from, among others, straight run naphta polymer gasoline, 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 addition, the motor fuel composition may contain any of the additives generally employed in gasoline. Thus, the fuel composition can contain conventional carburetor detergents, anti-knock compounds such as tetraethyl lead compounds, anti-icing additives, upper cylinder lubricating oils, and the like. A motor fuel composition representing the best mode of practicing the instant invention is set forth in Example IV, below.

Example IV

In the best mode of practicing the instant invention, 85.6 g/m³ (30 PTB) of the reaction product set forth in Example I (equivalent to 0.01 weight percent of reaction product component based on the weight of the fuel composition) and 584.9 g/m³ (205 PTB) (0.07 weight percent) of a composition (ORONITE OGA-472) containing approximately 60 parts by weight polyisobutylene ethylene diamine, approximately 13 parts by weight polyisobutylene, and approximately 27 parts by weight light aromatic distillate comprising xylene and Cg alkylbenzenes were added to a major amount of a base motor fuel composition which comprises a mixture of hydrocarbons boiling in the range of 30 to 230°C (90°F-450°F).
It has been found that a motor fuel composition containing 0.0005-5.0 weight percent, preferably 0.001-1.0 weight percent of Component (I) and 0.001-1.0 weight percent, preferably 0.01-0.5 weight percent of Component (II) is effective in both minimizing and reducing the ORI of a gasoline internal combustion engine, and in improving carburetor detergency and intake valve cleanliness of the motorfuel. These improvements have been demonstrated in ORI and carburetor detergency tests where the performance characteristics of a base motor fuel composition containing a commercial fuel additive and an improved motor fuel composition of the instant invention where compared.
The base motor fuel employed in the tests (herein designated as Base Fuel A) was a premium grade gasoline essentially unleaded (less than 0.05 g of tetraethyl lead per 3 litres), and comprised a mixture of hydrocarbons boiling in the gasoline boiling range consisting of about 22% aromatic hydrocarbons, 11% olefinic carbons, and 67% paraffinic hydrocarbons, boiling in the range from 30 to 230°C (90°F to 450°F).
In preparing motor fuels for the ORI and carburetor, intake valve and manifold detergency tests, a suitable amount of the reaction product component of the instant invention was added directly to Base Fuel A without additional solvents being necessary. As previously stated, the gasoline solubility of the reacticn product component of the instant invention is attributed to the presence of a large number of polyoxypropylene ether moieties in combination which polyoxyethylene and polyoxybutylene ether moieties.
The ORI tendencies of Base Fuel A containing 171.2 g/m³ (60 PTB) of a commercial fuel additive, (equivalent to about 0.02 weight percent of reaction product based on the weight of the fuel composition), as well as a motor fuel composition of the instant invention, as exemplified by Example IV, were measured via the Fuel Related Deposit Test (FRDT). The test measures the octane requirement of an engine for a particular motor fuel as a function of varying engine speed and load. This test employs a 1.8 liter Chevrolet engine controlled by a dedicated computer which operates the engine speed and load controls, test stand safeties, and data acquisition. Due to the multifunctional capabilities of the computer ccntrolled system, the test cycle very closely simulates an actual engine in a vehicle. The computer can change the engine speed and load quickly and often, and therefore provides a good simulation of a vehicle driving in an urban environment.
The experimental results obtained from the FRDT for Base Fuel A containing 171.2 g/m³ (60 PTB) of commercial fuel additive and a motor fuel composition of the instant invention (Example IV) are set forth in Figure 1. As illustrated by Figure 1, the octane requirement of the engine using Base Fuel A containing 171.2 g/m³ (60 PTB) of commercial fuel additive was consistently higher than the corresponding octane requirement of the engine using a motor fuel composition of the instant invention over the duration of the test. The one exception to this was the engine octane requirement results obtained for Run # 2, where the octane requirement of Base Fuel A containing 171.2 g/m³ (60 PTB) of commercial additive significantly decreased between 150 and 200 hours of engine operation (see broken lines in Figure 1). However, this unusual result was due to engine ignition problems in Run # 2, and does not detract from the superiority of the instant invention over a motor fuel containing a commercial fuel additive. The data set forth in Figure 1 thus indicate that a motor fuel composition of the instant invention has reduced ORI tendencies in comparison with a typical commercially available motor fuel composition.
The carburetor intake valve and intake manifold detergency properties of a commercially available motor fuel and a motorfuel composition of the instant invention (Example IV) were also measured via the Merit Rating Test. This test may be described as follows. At the end of a FRDT run for a given motor fuel composition, portions of the engine are dissassembled and various engine components are visually examined to determine the extent of deposit formation. This is determined via a visual rating system scaled from 1-10, with a value of 10 being a clean component and a value of 1 being a deposit-laden component.
The experimental results obtained from the Merit Rating Test are set forth in Table I. As illustrated by Table I, a motor fuel composition of the instant invention is approximately as effective (based upon merit ratings) as a commercially available fuel. In addition, a motor fuel composition of the instant invention shows improved valve deposit control, in view of both valve merit rating and reduced valve deposit weight.

Claims

1. A motor fuel composition comprising a mixture of hydrocarbons boiling in the range from 30 to 230°C (90 to 450°F) and (I) 0.0005 to 5.0 weight percent of a reaction product obtained by reacting at a temperature of 30°C-200°C:

(a) 1 mole of a dibasic acid anhydride of the formula

where each R₁ is H or C₁-C₅ alkyl ;

(b) 1-2 moles of a polyoxyalkylene diamine of the formula

where R₅ and R₆ are C₁-C₁₂ alkylene groups, q and r are 0 or 1, c is 5-150, b + d is 5-150, and a + e is 2-12; and

(c) 1-2 moles of a hydrocarbyl polyamine which may be either :

(i) a hydrocarbyl polyamine of the formula

where R₂ is alkyl having from 1-24 carbon atoms, R₃ is alkylene having 1 to 6 carbon atoms, and x is 1-10; or

(ii) a N-alkyl-alkylene diamine of the formula

where R₄ is an aliphatic hydrocarbon radical having 1-24 carbon atoms and n is 1-6, characterised in that the composition further comprises (II) from 0.001-1.0 weight percent of a mixture comprising a hydrocarbon solvent and :

(a) 50-75 parts by weight of polyisobutylene ethylene diamine of the formula

and

(b) 5-25 parts by weight of polyisobutylene of the formula

where z is 30-40.

2. A composition according to Claim 1 characterised in that said reaction product (I) is obtained by reacting 1 mole of said dibasic acid anhydride with 1.5 moles of said polyoxyalkylene diamine and 1 mole of said hydrocarbyl polyamine or N-alkyl-alkylene diamine.

3. A composition according to Claim 1 or Claim 2 characterised in that said dibasic acid anhydride reactant is maleic anhydride.

4. A composition according to any of the preceding Claims characterised in that said polyoxyalkylene diamine reactant is of the formula

where c is 8-50, b + d is 8-50, and a + e is 4-8.

5. A composition according to any of the preceding claims, characterised in that said hydrocarbyl polyamine reactant is either :

(III) a hydrocarbyl polyamine of the formula:

where R₂ is alkyl having from 12-20 carbon atoms, R₃ is alkylene having from 1-5 carbon atoms, and x is 1-5, or

(IV) a N-alkyl-alkylene diamine of the formula

where R₄ is an aliphatic hydrocarbon radical having 12-20 carbon atoms, and n is 3.

6. A composition according to Claim 5, characterised in that said n-alkyl-alkylene diamine reactant is

N-coco-1,3-diaminopropane ;

N-soya-1,3-diaminopropane ;

N-tallow-1,3-diaminopropane or

N-oleyl-1,3-diaminopropane.

7. A composition according to any one of claims 1 to 6 characterised in that the reaction product additive (I) is present in an amount of 0.0001-1.0 weight percent.

8. A composition according to claim 7, characterised in that the amount of reaction product additive (I) is 0.01-0.1 weight percent.

9. A composition according to any one of Claims 1 to 8, characterised in that the composition additionally comprises from 0.001-1.0 weight percent of a polyolefin polymer or copolymer, or the corresponding hydrogenated polymer or copolymer, or mixtures thereof, of a C₂-C_e unsaturated hydrocarbon, said polyolefin polymer or copolymer having a molecular weight of 500-3500.

10. A composition according to Claim 9, characterised in that said polyolefin polymer or copolymer component is derived from an unsaturated hydrocarbon selected from ethylene, propylene, isopropylene, butylene, isobutylene, amylene, hexylene, isoprene and butadiene.

11. A composition according to Claim 10, characterised in that said polyolefin polymer, copolymer, or corresponding hydrogenated polymer or copolymer component has a molecular weight of 650-2600.

12. A composition according to Claim 11 characterised in that said polyolefin polymer component is a polypropylene having a molecular weight of 750-1000.

13. A composition according to Claim 12, characterised in that said polyolefin polymer component is a polypropylene with an average molecular weight of 800.

14. A composition according to Claim 11, characterised in that said polyolefin polymer component is a polyisobutylene having a molecular weight of 1000-1500.

15. A composition according to Claim 14, characterised in that said polyolefin polymer component is a polyisobutylene having an average molecular weight of 1300.

16. A composition according to any one of Claims 9 to 15, characterised in that said polyolefin polymer or copolymer component is present in an amount of 0.01-0.5 weight percent.

17. A composition according to any one of claims 1 to 16 characterised in that z is 32-35.

18. A composition according to any one of Claims 1 to 17 characterised in that said hydrocarbon solvent in (II) is an aromatic distillate comprising xylene and Cg alkylbenzene compounds.

19. A composition according to any one of Claims 1 to 18, characterised in that the composition includes from 0.01-0.5 weight percent of a mixture comprising an aromatic distillate, 60 parts by weight of said polyisobutylene ethylene diamine and 10-20 parts by weight of said polyisobutylene, and in which z has a value of 32-35.

20. A concentrate composition, characterised in that it comprises a hydrocarbon solvent in admixture with: from 0.1-10.0 weight percent of the reaction product (I) defined in Claim 1, and 25.0 to 75.0 weight percent of the mixture (II) defined in Claim 1.