Quaternary ammonium salts containing non-halogen anions as anticorrosive agents

Abstract

Disclosed are quaternary ammonium salts containing non-halogen anions (e.g., quaternary ammonium carbonates, bicarbonates, and mixtures thereof) as anti-corrosive agents. The invention relates to a method for inhibiting the corrosion of metal surfaces by applying a composition containing one or more quaternary ammonium carbonate or bicarbonate. The disclosure is also directed to anti-corrosive coatings for metal substrates containing these compounds, to metal substrates having these anticorrosive coatings, and to aqueous cleaning solutions containing these compounds.

1 . A method for inhibiting corrosion of a metal substrate comprising the step of contacting the substrate with a composition comprising 
 (a) at least one quaternary ammonium salt containing a non-halogen anion, and    (b) optionally, a solvent.    
   
   
       2 . A method for inhibiting corrosion of a metal substrate comprising the step of contacting the substrate with a composition comprising 
 (a) at least one quaternary ammonium salt containing a non-halogen anion other than carbonate and bicarbonate, and    (b) optionally, a solvent.    
   
   
       3 . The method of  claim 1  or, wherein the quaternary ammonium salt has the formula  
     
       
         
         
             
             
         
       
     
     wherein R 1  is an optionally aryl-substituted C 1-20  alkyl group, and R 2  is an optionally aryl-substituted C 1-20  alkyl group, R 3  and R 4  independently of each other are C 1-4  alkyl groups, X n−  is an anion selected from the group consisting of hydroxide, carbonate, bicarbonate, phosphates, phosphites, hypophosphite, nitrate, sulfates, borates, anions of saturated and unsaturated acyclic C 1-20  monocarboxylic acids, anions of saturated and unsaturated C 2-20  dicarboxylic acids, and anions of hydroxy-substituted carboxylic acids, and n denotes the appropriate number of negative charges of said anion.  
   
   
       4 . The method of  claim 2 , wherein R 3  and R 4  are methyl groups.  
   
   
       5 . The method of  claim 2 , wherein R 1  and R 2  are the same C 1-20  alkyl groups.  
   
   
       6 . The method of  claim 2 , wherein R 1  and R 2  are C 10  alkyl groups.  
   
   
       7 . The method of  claim 6 , wherein R 1  and R 2  are n-C 10  alkyl groups.  
   
   
       8 . The method of  claim 2 , wherein R 1  is methyl.  
   
   
       9 . The method of  claim 8 , wherein R 1  and R 2  are methyl.  
   
   
       10 . The method of  claim 2 , wherein R 1  is benzyl or phenylethyl.  
   
   
       11 . The method of  claim 1 , wherein the composition further comprises a surfactant selected from the group consisting of amine oxides, linear alcohol ethoxylates, secondary alcohol ethoxylates, ethoxylate ethers, betaines, fatty acids containing from 6 to 22 carbon atoms, salts of fatty acids containing from 6 to 22 carbon atoms, and mixtures thereof.  
   
   
       12 . The method of  claim 11 , wherein the surfactant is nonylphenol ethoxylate.  
   
   
       13 . The method of  claim 1 , wherein the metal substrate is in an oil environment.  
   
   
       14 . The method of  claim 13 , wherein oil environment comprises a petroleum distillate.  
   
   
       15 . The method of  claim 14 , wherein the petroleum distillate is selected from the group consisting of kerosene, white spirit, hydrocarbon fractions, and mixtures thereof.  
   
   
       16 . The method  claim 1 , wherein the composition further comprises at least one ingredient selected from the group consisting of builders, colorants, perfumes and fragrances.  
   
   
       17 . The method of  claim 1 , wherein the metal substrate is selected from the group consisting of steel, cast iron, aluminum, metal alloys and combinations thereof.  
   
   
       18 . An anti-corrosive coating for a metal substrate comprising 
 (a) at least one quaternary ammonium salt containing a non-halogen anion, and    (b) a coating material.    
   
   
       19 . An anti-corrosive coating for a metal substrate comprising 
 (a) at least one quaternary ammonium salt of the formula                          wherein R 1  is an optionally aryl-substituted C 1-20  alkyl group, and R 2  is an optionally aryl-substituted C 1-20  alkyl group, R 3  and R 4  independently of each other are C 1-4  alkyl groups, X n−  is an anion selected from the group consisting of hydroxide, carbonate, bicarbonate, phosphates, phosphites, hypophosphite, nitrate, sulfates, borates, anions of saturated and unsaturated acyclic C 1-20  monocarboxylic acids, anions of saturated and unsaturated C 2-20  dicarboxylic acids, and anions of hydroxy-substituted carboxylic acids, and n denotes the appropriate number of negative charges of said anion, and    (b) a coating material.    
   
   
       20 . The anti-corrosive coating of  claim 18 , wherein the quaternary ammonium salt is dispersed in the coating material.  
   
   
       21 . A metal substrate having the anti-corrosive coating of  claim 18  on at least one surface thereof.  
   
   
       22 . An anti-corrosive cleaning solution comprising at least one quaternary ammonium salt containing a non-halogen anion.  
   
   
       23 . An anti-corrosive metalworking fluid comprising an aqueous or non-aqueous solution comprising at least one quaternary ammonium salt containing a non-halogen anion.  
   
   
       24 . A corrosion inhibitor for use in powder metallurgy comprising an aqueous or non-aqueous solution comprising at least one quaternary ammonium salt containing a non-halogen anion.  
   
   
       25 . The method of  claim 1 , wherein the at least one quaternary ammonium salt is selected from the group consisting of quaternary ammonium carbonates, quaternary ammonium bicarbonates, and mixtures thereof.  
   
   
       26 . The method of  claim 25 , wherein the quaternary ammonium carbonate has the formula  
     
       
         
         
             
             
         
       
     
     wherein R 5  is an optionally aryl-substituted C 1-20  alkyl group, and R 6  is an optionally aryl-substituted C 1-20  alkyl group.  
   
   
       27 . The method of  claim 25 , wherein the quaternary ammonium bicarbonate has the formula  
     
       
         
         
             
             
         
       
     
     wherein R 5  is an optionally aryl-substituted C 1-20  alkyl group, and R 6  is an optionally arylsubstituted C 1-20  alkyl group.  
   
   
       28 . The method of  claim 26 , wherein R 5  and R 6  are the same C 1-20  alkyl groups.  
   
   
       29 . The method of  claim 26 , wherein R 5  and R 6  are C 10  alkyl groups.  
   
   
       30 . The method of  claim 29 , wherein R 5  and R 6  are n-C 10  alkyl groups.  
   
   
       31 . The method of  claim 29 , wherein the quaternary ammonium carbonate is didecyldimethylammonium carbonate and the quaternary ammonium bicarbonate is didecyldimethylammonium bicarbonate.  
   
   
       32 . The method of  claim 26 , wherein R 5  is methyl.  
   
   
       33 . The method of  claim 31 , wherein R 5  and R 6  are methyl.  
   
   
       34 . The method of  claim 26 , wherein R 5  is benzyl or phenylethyl.  
   
   
       35 . The method of  claim 25 , wherein the composition further comprises a surfactant selected from the group consisting of amine oxides, linear alcohol ethoxylates, secondary alcohol ethoxylates, ethoxylate ethers, betaines, fatty acids containing from 6 to 22 carbon atoms, salts of fatty acids containing from 6 to 22 carbon atoms, and mixtures thereof.  
   
   
       36 . The method of  claim 35 , wherein the surfactant is nonylphenol ethoxylate.  
   
   
       37 . The method of  claim 24 , wherein the metal substrate is in an oil environment.  
   
   
       38 . The method of  claim 37 , wherein oil environment comprises a petroleum distillate.  
   
   
       39 . The method of  claim 38 , wherein the petroleum distillate is selected from the group consisting of kerosene, white spirit, hydrocarbon fractions, and mixtures thereof.  
   
   
       40 . The method of  claim 24 , wherein the composition further comprises at least one ingredient selected from the group consisting of builders, colorants, perfumes and fragrances.  
   
   
       41 . The method of  claim 24 , wherein the metal substrate is selected from the group consisting of steel, cast iron, aluminum, metal alloys and combinations thereof.  
   
   
       42 . The anti-corrosive coating for a metal substrate of  claim 19 , wherein the at least one quaternary ammonium salt is selected from quaternary ammonium carbonates, quaternary ammonium bicarbonates, and mixtures thereof.  
   
   
       43 . The anti-corrosive coating of  claim 42 , wherein the quaternary ammonium carbonate, bicarbonate, or mixture thereof is dispersed in the coating material.  
   
   
       44 . A metal substrate having the anti-corrosive coating of  claim 42  on at least one surface thereof.  
   
   
       45 . The anti-corrosive cleaning solution of  claim 22 , comprising an aqueous solution comprising at least one quaternary ammonium carbonate, quaternary ammonium bicarbonate, or a mixture thereof.  
   
   
       46 . The anti-corrosive metalworking fluid of  claim 23 , wherein the at least one quaternary ammonium salt is selected from quaternary ammonium carbonates, quaternary ammonium bicarbonates, and mixtures thereof.  
   
   
       47 . The corrosion inhibitor for use in powder metallurgy of  claim 24 , wherein the at least one quaternary ammonium salt is selected from quaternary ammonium carbonates, quaternary ammonium bicarbonates, and mixtures thereof.