Fuel for motor vehicles

Abstract

Fuel for motor vehicles comprising an emulsion between water and a liquid hydrocarbon, and an anti-cavitation additive comprising a copolymer including 20-80% in moles, preferably 35-70% in moles, of units containing at least one carboxylic group and 80-20% in moles, preferably 65-30% in moles, of units deriving from at least one monomer having an ethylene unsaturation, and wherein at least 20% in moles of the carboxylic groups, preferably 30-90% in moles, is in the form of at least one derivative selected from carboxylate salt, ester, amide and imide.

1 . A fuel for motor vehicles comprising an emulsion between water and a liquid hydrocarbon, and an anti-cavitation additive, including a copolymer comprising 20-80% in moles of units containing at least one carboxylic group and 80-20% in moles of units deriving from at least one monomer having an ethylene unsaturation, and wherein at least 20% in moles of the carboxylic groups is in the form of at least one derivative selected from carboxylate salt, ester, amide and imide.  
   
   
       2 . The fuel for motor vehicles according to  claim 1 , wherein the copolymer has an average molecular weight Mw ranging from 700 to 3000.  
   
   
       3 . The fuel for motor vehicles according to  claim 1  or  2 , wherein the carboxylic groups present in the copolymer are partially or totally salified by means of a neutralization reaction carried out with an inorganic or organic base.  
   
   
       4 . The fuel for motor vehicles according to  claim 3 , wherein the base is selected from: hydroxides of alkaline or alkaline earth metals, ammonium hydroxide or quaternary ammonium hydroxides, sodium and/or potassium carbonates and bicarbonates, C 1 -C 30  aliphatic alkyl amines.  
   
   
       5 . The fuel for motor vehicles according to  claim 1  or  2 , wherein the carboxylic groups present in the copolymer are partially or totally esterified by means of an alcohol or a polyol with a low number of carbon atoms.  
   
   
       6 . The fuel for motor vehicles according to  claim 1  or  2 , wherein the carboxylic acid groups present in the copolymer are partially or totally transformed into amide or imide groups by means of thermal treatment in the presence of a primary or secondary aliphatic amine with a low number of carbon atoms.  
   
   
       7 . The fuel for motor vehicles according to any of the previous claims, wherein the units containing at least one carboxylic group derive from a C 3 -C 10  aliphatic monocarboxylic acid having an ethylene unsaturation, or from a C 4 -C 10  aliphatic dicarboxylic acid having an ethylene unsaturation.  
   
   
       8 . The fuel for motor vehicles according to any of the previous claims, wherein the monomer having an ethylene unsaturation is selected from: C 2 -C 12  α-olefins, C 1 -C 6  alkyl esters of (meth)acrylic acid, vinyl ethers and vinyl esters.  
   
   
       9 . The fuel for motor vehicles according to any of the previous claims, wherein the liquid hydrocarbon has a viscosity at 40° C. ranging from 1 to 5.3 cSt and a density at 15° C. ranging from 0.75 to 1.1 kg/dm 3 .  
   
   
       10 . The fuel for motor vehicles according to any of the previous claims, wherein the water is present in a quantity ranging from 2 to 40% by weight, with respect to the total.  
   
   
       11 . The fuel for motor vehicles according to any of the previous claims, wherein the emulsion is of the water-in-oil type.  
   
   
       12 . The fuel for motor vehicles according to  claim 11 , wherein the emulsion comprises at least one emulsifying agent whose concentration ranges from 0.1 to 10% by weight with respect to the total.  
   
   
       13 . The fuel for motor vehicles according to any of the previous claims, wherein said at least one emulsifying agent has an HLB (Hydrophilic-Lipophilic Balance) value ranging from 2 to 10.  
   
   
       14 . The fuel for motor vehicles according to  claim 13 , wherein said at least one emulsifying agent has an HLB (Hydrophilic-Lipophilic Balance) value ranging from 3 to 8.  
   
   
       15 . The fuel for motor vehicles according to any of the previous claims, wherein said at least one emulsifying agent is a product obtained by the reaction of: (a1) a polyolefinic oligomer functionalized with at least one group deriving from a dicarboxylic acid, or one of its derivatives; with (a2) a polyoxy-alkylene comprising linear oxy-alkylene units, said polyoxy-alkylene being bound to a long-chain alkyl group optionally containing at least one ethylene unsaturation.  
   
   
       16 . The fuel for motor vehicles according to any of the claims from 1 to 14, wherein said at least one emulsifying agent is a product obtained by the reaction of (b1) a carboxylic acylating agent containing a hydrocarbon chain having from 50 to 500 carbon atoms, with (b2) ammonia or an amine.  
   
   
       17 . A process for feeding an internal combustion engine which comprises: feeding a fuel to a combustion chamber of said engine; igniting said fuel in said combustion chamber, wherein said fuel comprises an emulsion between water and a liquid hydrocarbon, and an anti-cavitation additive according to any of the claims from 1 to 16.  
   
   
       18 . The process according to  claim 17 , wherein the internal combustion engine is a diesel cycle engine.