Oxidation-stabilized lubricant additives for highly desulfurized fuel oils

Abstract

An additive for improving the lubricity of fuel oils having a maximum sulfur content of 0.035% by weight, comprising A) at least one partial ester composed of a di- or polyhydric alcohol and unsaturated and optionally also saturated fatty acids whose carbon chain lengths are between 8 and 30 carbon atoms, at least 60% of the fatty acid radicals containing at least one double bond, and B) at least one alkylphenol-aldehyde resin, obtainable by the condensation of (i) at least one alkylphenol having at least one C 6 -C 24 -alkyl or C 6 -C 24 -alkenyl radical and (ii) at least one aldehyde or ketone,  to a degree of condensation of between 2 and 50 alkylphenol units.

What is claimed is:  
     
         1 . An additive for improving the lubricity of fuel oils having a maximum sulfur content of 0.035% by weight, comprising 
 A) at least one partial ester composed of a di- or polyhydric alcohol and unsaturated and optionally also saturated fatty acids whose carbon chain lengths are between 8 and 30 carbon atoms, at least 60% of the fatty acid radicals containing at least one double bond, and    B) at least one alkylphenol-aldehyde resin, obtainable by the condensation of 
 (i) at least one alkylphenol having at least one C 6 -C 24 -alkyl or C 6 -C 24 -alkenyl radical and  
 (ii) at least one aldehyde or ketone,  
    to a degree of condensation of between 2 and 50 alkylphenol units.    
     
     
         2 . An additive as claimed in  claim 1 , wherein the iodine number of constituent A) is more than 50 g of I/100 g of ester.  
     
     
         3 . An additive as claimed in  claim 1  and/or  2 , wherein the OH number of constituent A) is between 10 and 200 mg of KOH/g of ester.  
     
     
         4 . An additive as claimed in one or more of  claims 1  to  3 , wherein the fatty acids which are a constituent of the fatty acid mixture contain from 10 to 26 carbon atoms.  
     
     
         5 . An additive as claimed in one or more of  claims 1  to  4 , wherein the fatty acid mixtures comprise up to 20% by weight of saturated fatty acids.  
     
     
         6 . An additive as claimed in one or more of  claims 1  to  5 , wherein the fatty acid mixtures comprise one or more dicarboxylic acids.  
     
     
         7 . An additive as claimed in one or more of  claims 1  to  6 , wherein the alcohols contain from 2 to 6 carbon atoms.  
     
     
         8 . An additive as claimed in one or more of  claims 1  to  7 , wherein the alcohols contain from 2 to 5 hydroxyl groups, but a maximum of one hydroxyl group per carbon atom.  
     
     
         9 . An additive as claimed in one or more of  claims 1  to  8 , which also comprises at least one nitrogen-containing paraffin dispersant.  
     
     
         10 . An additive as claimed in one or more of  claims 1  to  9 , which also comprises at least one ethylene copolymer.  
     
     
         11 . An additive as claimed in one or more of  claims 1  to  10 , which also comprises at least one comb polymer.  
     
     
         12 . A fuel oil having a maximum sulfur content of 0.035% by weight, comprising an additive as claimed in one or more of  claims 1  to  11  in amounts of from 0.001 to 0.5% by weight, based on the fuel oil.  
     
     
         13 . The use of an additive as claimed in one or more of  claims 1  to  11  in amounts of from 0.001 to 0.5% by weight, based on the fuel oil, for improving the lubricity of fuel oils having a maximum sulfur content of 0.035% by weight.