Corrosion inhibitors for fuels and lubricants

Abstract

The present invention relates to novel uses of corrosion inhibitors in fuels and lubricants.

1 : A process, comprising inhibiting corrosion in a fuel or lubricant by contacting the fuel or lubricant with a copolymer, wherein the copolymer is obtained by:
 (I) copolymerizing
 (A) at least one ethylenically unsaturated mono- or dicarboxylic acid or derivatives thereof, 
 (B) at least one α-olefin having from at least 12 up to and including 30 carbon atoms, 
 (C) optionally at least one further aliphatic or cycloaliphatic olefin which has at least 4 carbon atoms and is different than (B), and 
 (D) optionally one or more further copolymerizable monomers other than monomers (A), (B) and (C), selected from the group consisting of
 (Da) vinyl esters, 
 (Db) vinyl ethers, 
 (Dc) (meth)acrylic esters of alcohols having at least 5 carbon atoms, 
 (Dd) allyl alcohols or ethers thereof, 
 (De) N-vinyl compounds selected from the group consisting of vinyl compounds of heterocycles containing at least one nitrogen atom, N-vinylamides or N-vinyllactams, 
 (Df) ethylenically unsaturated aromatics, 
 (Dg) α,β-ethylenically unsaturated nitriles, 
 (Dh) (meth)acrylamides and 
 (Di) allylamines, 
 
   
       to obtain a copolymer precursor; and then
 (II) optionally partly hydrolyzing anhydride functionalities, carboxylic ester functionalities, or both, present in the copolymer precursor, with the proviso that more than 90% of the anhydride and carboxylic ester functionalities present remain intact after the hydrolyzing, to obtain the copolymer. 
 
     
     
         2 : The process of  claim 1 , comprising contacting the copolymer with a fuel comprising at least one metal selected from the group consisting of sodium, zinc, magnesium and calcium. 
     
     
         3 : The process of  claim 1 , wherein monomer (A) is selected from the group consisting of acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate, methyl methacrylate and maleic anhydride. 
     
     
         4 : The process of  claim 1 , wherein monomer (B) is an α-olefin having from 14 to 26 carbon atoms. 
     
     
         5 : The process of  claim 1 , wherein olefin (C) is a polymer having more than 30 carbon atoms derived from units of propene, 1-butene, 2-butene, isobutene, or mixtures thereof, and having an average molecular weight Mw ranging from 500 to 5000 g/mol. 
     
     
         6 : The process of  claim 1 , wherein a mixture of olefins (B) and (C) averaged to molar amounts thereof has at least 12 carbon atoms. 
     
     
         7 : The process of  claim 1 , wherein the copolymerizing (I) includes a monomer (D) selected from the group consisting of (Da), (Db), (Dc), (De) and (Df). 
     
     
         8 : The process of  claim 1 , wherein a molar ratio of (A)/((B) and (C)) (in total) is from 10:1 to 1:10. 
     
     
         9 : The process of  claim 8 , wherein the molar ratio of monomer (B) to monomer (C) is from 1:0.05 to 10. 
     
     
         10 : The process of  claim 8 , wherein a proportion of the one or more further copolymerizable monomers (D), based on an amount of the monomers (A), (B) and optionally (C) (in total), is 5 to 200 mol %. 
     
     
         11 : The process of  claim 1 , wherein maleic anhydride is used as component (A) and the optional reaction step (II) is not conducted. 
     
     
         12 : The process of  claim 1 , wherein maleic anhydride is used as component (A) and more than 90% and up to 99.9% of the anhydride functionalities remain intact in reaction step (II). 
     
     
         13 : The process of  claim 1 , wherein the inhibiting corrosion involves inhibiting corrosion of at least one iron surface, steel surface, nonferrous metal surface, or combination thereof. 
     
     
         14 : The process of  claim 1 , wherein the inhibiting corrosion involves inhibiting corrosion of copper and copper-containing alloys. 
     
     
         15 : The process of  claim 1 , wherein the fuel is a diesel or gasoline fuel.