Deposit control additives for direct injection gasoline engines

Abstract

Deposits in a direct injection gasoline engine are reduced by providing as fuel for the operation of said direct injection engine a fuel composition comprising the fuel-soluble reaction products obtained by reacting (i) a monocarboxylic acid of the formula: wherein R 1 is a saturated or unsaturated, linear or branched, C 8-18 hydrocarbyl group; and (ii) an amine of the formula NH 2 —CH 2 —CH 2 —NH—R 2 , wherein R 2 comprises (C x H 2x Z) y H, wherein x=2 or 3, y=0-4 and Z=NH or O.

We claim:  
     
         1 . A method for controlling deposits in a direct injection gasoline engine which comprises introducing into a direct injection gasoline engine with the combustion intake charge a spark-ignition fuel composition comprising a) a spark-ignition fuel and b) a fuel-soluble compound comprising the reaction products of (i) a monocarboxylic acid of the formula:  
       
         
           
           
               
               
           
         
       
       wherein R 1  is a saturated or unsaturated; linear, branched or cyclic; C 7-23  hydrocarbyl group; and (ii) an amine of the formula NH 2 —CH 2 —CH 2 —NH—R 2 , wherein R 2  comprises (C x H 2x Z) y H, wherein x=2 or 3, y=0-4 and Z=NH or O.  
     
     
         2 . The method of  claim 1  wherein the spark-ignition fuel composition comprises the fuel-soluble compound (b) in proportions effective to reduce the volume of injector deposits in a direct injection gasoline engine operated on a spark-ignition fuel containing an injector deposit-controlling amount of said fuel-soluble compound (b) to below the volume of injector deposits in said direct injection gasoline engine operated in the same manner on the same spark-ignition fuel except that it is devoid of a fuel-soluble compound (b).  
     
     
         3 . The method of  claim 1  wherein the spark-ignition fuel comprises gasoline.  
     
     
         4 . The method of  claim 1  wherein the spark-ignition fuel comprises a blend of hydrocarbons of the gasoline boiling range and a fuel-soluble oxygenated compound.  
     
     
         5 . The method of  claim 1  wherein the fuel-soluble compound (b) has an Iodine Value of 150 or less.  
     
     
         6 . The method of  claim 5  wherein the fuel-soluble compound (b) has an Iodine Value of 125 or less.  
     
     
         7 . The method of  claim 6  wherein the fuel-soluble compound (b) has an Iodine Value of 75 or less.  
     
     
         8 . The method of  claim 7  wherein the fuel-soluble compound (b) has an Iodine Value of 25 or less.  
     
     
         9 . The method of  claim 8  wherein the fuel-soluble compound (b) has an Iodine Value of 5 or less.  
     
     
         10 . The method of  claim 1  wherein the monocarboxylic acid is saturated.  
     
     
         11 . The method of  claim 1  wherein the monocarboxylic acid comprises isostearic acid.  
     
     
         12 . The method of  claim 1  wherein the monocarboxylic acid comprises 2-ethylhexanoic acid.  
     
     
         13 . The method of  claim 1  wherein the monocarboxylic acid comprises naphthenic acid.  
     
     
         14 . The method of  claim 1  wherein the fuel-soluble compound (b) is present in an amount sufficient to provide 0.1-15 pounds by weight of compound (b) per thousand barrels by volume of fuel.  
     
     
         15 . The method of  claim 1  wherein the fuel composition further comprises at least one amine detergent selected from the group consisting of nitrogen-containing derivatives of hydrocarbyl succinic acylating agents, Mannich condensation products, hydrocarbyl amines and polyetheramines.  
     
     
         16 . The method of  claim 1  wherein the fuel composition further comprises a carrier fluid selected from the group consisting of 1) a mineral oil or a blend of mineral oils that have a viscosity index of less than about 120, 2) one or more poly-α-olefin oligomers, 3) one or more poly (oxyalkylene) compounds having an average molecular weight in the range of about 500 to about 3000, 4) one or more polyalkenes, 5) one or more polyalkyl-substituted hydroxyaromatic compounds and 6) mixtures thereof.  
     
     
         17 . The method of  claim 16  wherein the carrier fluid comprises at least one poly (oxyalkylene) compound.  
     
     
         18 . The method of  claim 1  wherein the fuel composition further comprises at least one additive selected from the group consisting of antioxidants, carrier fluids, metal deactivators, dyes, markers, corrosion inhibitors, biocides, antistatic additives, drag reducing agents, demulsifiers, emulsifiers, dehazers, anti-icing additives, antiknock additives, anti-valve-seat recession additives, lubricity additives, surfactants and combustion improvers.  
     
     
         19 . A fuel composition comprising a) a spark-ignition fuel; b) the reaction products obtained by reacting (i) a monocarboxylic acid of the formula:  
       
         
           
           
               
               
           
         
       
       wherein R 1  is a saturated or unsaturated; linear, branched or cyclic; C 7-23  hydrocarbyl group; and (ii) an amine of the formula NH 2 —CH 2 —CH 2 —NH—R 2 , wherein R 2  is selected from the group consisting of (C x H 2x Z) y H, wherein x=2 or 3, y=0-4 and Z=NH or O; and c) an amine detergent selected from the group consisting of nitrogen-containing derivatives of hydrocarbyl succinic acylating agents, Mannich condensation products, hydrocarbyl amines and polyetheramines.  
     
     
         20 . The fuel composition of  claim 19  wherein the fuel-soluble compound (b) is present in an amount sufficient to provide 0.1-15 pounds by weight of compound (b) per thousand barrels by volume of fuel.  
     
     
         21 . The fuel composition of  claim 19  wherein the fuel-soluble compound (b) has an Iodine Value of 150 or less.  
     
     
         22 . The fuel composition of  claim 21  wherein the fuel-soluble compound (b) has an Iodine Value of 125 or less.  
     
     
         23 . The fuel composition of  claim 22  wherein the fuel-soluble compound (b) has an Iodine Value of 75 or less.  
     
     
         24 . The fuel composition of  claim 23  wherein the fuel-soluble compound (b) has an Iodine Value of 25 or less.  
     
     
         25 . The fuel composition of  claim 24  wherein the fuel-soluble compound (b) has an Iodine Value of 5 or less.  
     
     
         26 . The fuel composition of  claim 19  wherein the monocarboxylic acid of compound (b) comprises a saturated monocarboxylic acid.  
     
     
         27 . The fuel composition of  claim 19  wherein the monocarboxylic acid comprises isostearic acid.  
     
     
         28 . The fuel composition of  claim 19  wherein the monocarboxylic acid comprises 2-ethylhexanoic acid.  
     
     
         29 . The fuel composition of  claim 19  wherein the monocarboxylic acid comprises naphthenic acid.  
     
     
         30 . The fuel composition of  claim 19  wherein the fuel composition further comprises a carrier fluid selected from the group consisting of 1) a mineral oil or a blend of mineral oils that have a viscosity index of less than about 120, 2) one or more poly-α-olefin oligomers, 3) one or more poly (oxyalkylene) compounds having an average molecular weight in the range of about 500 to about 3000, 4) one or more polyalkenes, 5) one or more polyalkyl-substituted hydroxyaromatic compounds and 6) mixtures thereof.  
     
     
         31 . The fuel composition of  claim 30  wherein the carrier fluid comprises at least one poly (oxyalkylene) compound.  
     
     
         32 . The fuel composition of  claim 19  wherein the fuel composition further comprises at least one additive selected from the group consisting of antioxidants, carrier fluids, metal deactivators, dyes, markers, corrosion inhibitors, biocides, antistatic additives, drag reducing agents, demulsifiers, dehazers, anti-icing additives, antiknock additives, anti-valve-seat recession additives, lubricity additives and combustion improvers.  
     
     
         33 . A method of controlling deposits in a direct injection gasoline engine comprising adding to a spark-ignition fuel a fuel-soluble compound comprising the reaction products of (i) a monocarboxylic acid of the formula:  
       
         
           
           
               
               
           
         
       
       wherein R 1  is a saturated or unsaturated; linear, branched or cyclic; C 7-23  hydrocarbyl group; and (ii) an amine of the formula NH 2 —CH 2 —CH 2 NH—R 2 , wherein R 2  comprises (C x H 2x Z) y H, wherein x=2 or 3, y=0-4 and Z=NH or O; and operating a direct injection gasoline engine using said fuel containing b).