Corrosion inhibitor

Abstract

The corrosion inhibitor blend of at least one corrosion inhibitor base (which may be a Mannich reaction product), a solvent selected from the group consisting of C 1 acids and ester and salt derivatives thereof, and optionally a surfactant, has been found to be effective as a corrosion inhibitor for metals in acid media, particularly fluids containing halogen acids. The corrosion inhibitor has improved performance over similar or identical corrosion inhibitor compositions where an alcohol such as methanol is used as a solvent. Suitable, non-limiting possibilities for the solvent include, but are not necessarily limited to formic acid, formate salts, methyl formate, ethyl formate, benzyl formate, formate salts of amines, inorganic formate, and mixtures thereof.

I claim:  
     
         1 . A corrosion inhibitor comprising: 
 a. at least one corrosion inhibitor base selected from the group consisting of: 
 i) a Mannich reaction product, and  
 ii) a nitrogen-substituted heterocycle of 6 to 10 members quaternized with at least one alkyl or aryl halide; and  
   b. at least one first solvent selected from the group consisting of C 1  acids and ester derivatives thereof and salts thereof.    
     
     
         2 . The corrosion inhibitor of  claim 1  where the Mannich reaction product comprises the product of reaction of 
 (i) one mole of an ammonia derivative having at least one hydrogen attached to nitrogen and having no groups reactive under the conditions of reaction other than hydrogen,  
 (ii) from 1.5 to 10 moles of a carbonyl compound having at least one hydrogen atom on the carbon atom adjacent to the carbonyl group,  
 (iii) from 2 to 10 moles of an aldehyde different from the carbonyl compound, selected from the group consisting of aliphatic aldehydes having from 1 to 16 carbon atoms and aromatic aldehydes of the benzene series and having no functional groups other than aldehyde groups, and  
 (iv) from 0.6 to 24 parts by weight based on (1), (2), and (3) of a fatty acid having from 1 to 20 carbon atoms  
 at a temperature of from about 150° F. (66° C.) to about 250° F. (121° C.) for from about 1 to 16 hours.  
 
     
     
         3 . The corrosion inhibitor of  claim 1  where the at least one first solvent is selected from the group consisting of formic acid, formate salts, methyl formate, ethyl formate, benzyl formate, formate salts of amines, inorganic formates, and mixtures thereof.  
     
     
         4 . The corrosion inhibitor of  claim 1  where the components are present in the following proportions: 
 a. about 10 to 60 volume % corrosion inhibitor base; and  
 b. about 3 to 50 volume % solvent,  
 based on the total corrosion inhibitor.  
 
     
     
         5 . The corrosion inhibitor of  claim 1  further comprising a second solvent different from the first solvent present up to about 50 volume %, based on the total corrosion inhibitor.  
     
     
         6 . A corrosion inhibitor comprising: 
 a. at least one corrosion inhibitor base selected from the group consisting of: 
 i) a Mannich reaction product, and  
 ii) a nitrogen-substituted heterocycle of 6 to 10 members quatemized with at least one alkyl or aryl halide;  
   b. at least one first solvent selected from the group consisting of C 1  acids and ester derivatives thereof and salts thereof; and    c. at least one surfactant.    
     
     
         7 . The corrosion inhibitor of  claim 6  where the Mannich reaction product comprises the product of reaction of 
 (i) one mole of an ammonia derivative having at least one hydrogen attached to nitrogen and having no groups reactive under the conditions of reaction other than hydrogen,  
 (ii) from 1.5 to 10 moles of a carbonyl compound having at least one hydrogen atom on the carbon atom adjacent to the carbonyl group,  
 (iii) from 2 to 10 moles of an aldehyde different from the carbonyl compound, selected from the group consisting of aliphatic aldehydes having from 1 to 16 carbon atoms and aromatic aldehydes of the benzene series and having no functional groups other than aldehyde groups, and  
 (iv) from 0.6 to 24 parts by weight based on (1), (2), and (3) of a fatty acid having from 1 to 20 carbon atoms  
 at a temperature of from about 150° F. (66° C.) to about 250° F. (121° C.) for from about 1 to 16 hours.  
 
     
     
         8 . The corrosion inhibitor of  claim 6  where the at least one surfactant is an alcohol or an esterified alcohol that has been alkoxylated.  
     
     
         9 . The corrosion inhibitor of  claim 8  where the alcohol used to make the at least one surfactant has from about 6 to 30 carbon atoms.  
     
     
         10 . The corrosion inhibitor of  claim 6  where the at least one first solvent is selected from the group consisting of formic acid, formate salts, methyl formate, ethyl formate, benzyl formate, formate salts of amines, inorganic formates, and mixtures thereof.  
     
     
         11 . The corrosion inhibitor of  claim 6  where the components are present in the following proportions: 
 a. about 10 to 60 volume % corrosion inhibitor base;  
 b. about 3 to 50 volume % solvent; and  
 c. about 5 to 50 volume % surfactant,  
 based on the total corrosion inhibitor.  
 
     
     
         12 . The corrosion inhibitor of  claim 6  further comprising a second solvent different from the first solvent present up to about 50 volume %, based on the total corrosion inhibitor.  
     
     
         13 . A method of inhibiting the corrosion of metals in the presence of a liquid medium containing at least one halogen acid comprising including in the fluid a corrosion inhibitor comprising 
 a. at least one corrosion inhibitor base selected from the group consisting of: 
 i) a Mannich reaction product, and  
 ii) a nitrogen-substituted heterocycle of 6 to 10 members quaternized with at least one alkyl or aryl halide; and  
   b. at least one first solvent selected from the group consisting of C 1  acids and ester derivatives thereof and salts thereof.    
     
     
         14 . The method of  claim 13  where the corrosion inhibitor comprises at least one Mannich reaction product comprises the product of reaction of 
 (i) one mole of an ammonia derivative having at least one hydrogen attached to nitrogen and having no groups reactive under the conditions of reaction other than hydrogen,  
 (ii) from 1.5 to 10 moles of a carbonyl compound having at least one hydrogen atom on the carbon atom adjacent to the carbonyl group,  
 (iii) from 2 to 10 moles of an aldehyde different from the carbonyl compound, selected from the group consisting of aliphatic aldehydes having from 1 to 16 carbon atoms and aromatic aldehydes of the benzene series and having no functional groups other than aldehyde groups, and  
 (iv) from 0.6 to 24 parts by weight based on (1), (2), and (3) of a fatty acid having from 1 to 20 carbon atoms at a temperature of from about 150° F. (66° C.) to about 250° F. (121° C.) for from about 1 to 16 hours.  
 
     
     
         15 . The method of  claim 13  where in the corrosion inhibitor, the at least one first solvent is selected from the group consisting of formic acid, formate salts, methyl formate, ethyl formate, benzyl formate, formate salts of amines, inorganic formates, and mixtures thereof.  
     
     
         16 . The method of  claim 13  where the components of the corrosion inhibitor are present in the following proportions: 
 a. about 10 to 60 volume % corrosion inhibitor base; and  
 b. about 3 to 50 volume % solvent, based on the total corrosion inhibitor.  
 
     
     
         17 . The method of  claim 13  where the corrosion inhibitor further comprises a second solvent different from the first solvent, and the second solvent is present up to about 50 volume %, based on the total corrosion inhibitor.  
     
     
         18 . A method of inhibiting the corrosion of metals in the presence of a liquid medium containing at least one halogen acid comprising including in the fluid a corrosion inhibitor comprising 
 a. at least one corrosion inhibitor base selected from the group consisting of: 
 i) a Mannich reaction product, and  
 ii) a nitrogen-substituted heterocycle of 6 to 10 members quaternized with at least one alkyl or aryl halide;  
   b. at least one first solvent selected from the group consisting of C 1  acids and ester derivatives thereof and salts thereof; and    c. at least one surfactant.    
     
     
         19 . The method of  claim 18  where the corrosion inhibitor comprises at least one Mannich reaction product comprises the product of reaction of 
 (i) one mole of an ammonia derivative having at least one hydrogen attached to nitrogen and having no groups reactive under the conditions of reaction other than hydrogen,  
 (ii) from 1.5 to 10 moles of a carbonyl compound having at least one hydrogen atom on the carbon atom adjacent to the carbonyl group,  
 (iii) from 2 to 10 moles of an aldehyde different from the carbonyl compound, selected from the group consisting of aliphatic aldehydes having from 1 to 16 carbon atoms and aromatic aldehydes of the benzene series and having no functional groups other than aldehyde groups, and  
 (iv) from 0.6 to 24 parts by weight based on (1), (2), and (3) of a fatty acid having from 1 to 20 carbon atoms  
 at a temperature of from about 150° F. (66° C.) to about 250° F. (121° C.) for from about 1 to 16 hours.  
 
     
     
         20 . The method of  claim 18  where in the corrosion inhibitor, the at least one surfactant is an esterified alcohol that has been alkoxylated.  
     
     
         21 . The method of  claim 20  where in the surfactant, the alcohol used to make the at least one surfactant has from about 6 to 30 carbon atoms.  
     
     
         22 . The method of  claim 18  where in the corrosion inhibitor, the at least one first solvent is selected from the group consisting of formic acid, formate salts, methyl formate, ethyl formate, benzyl formate, formate salts of amines, inorganic formates, and mixtures thereof.  
     
     
         23 . The method of  claim 18  where the components of the corrosion inhibitor are present in the following proportions: 
 a. about 10 to 60 volume % corrosion inhibitor base;  
 b. about 3 to 50 volume % solvent;  
 c. about 5 to 50 vol. % surfactant; and  
 based on the total corrosion inhibitor.  
 
     
     
         24 . The method of  claim 18  where the corrosion inhibitor further comprises a second solvent different from the first solvent, and the second solvent is present up to about 50 volume %, based on the total corrosion inhibitor.  
     
     
         25 . The method of  claim 18  where the amount of corrosion inhibitor in the liquid ranges from about 0.1 to about 3.0% volume %.  
     
     
         26 . A fluid for contacting a metal surface, the fluid comprising 
 A. at least one halogen acid; and    B. a corrosion inhibitor comprising: 
 a. at least one corrosion inhibitor base selected from the group consisting of: 
 i) a Mannich reaction product, and  
 ii) a nitrogen-substituted heterocycle of 6 to 10 members quaternized with at least one alkyl or aryl halide; and  
 
 b. at least one first solvent selected from the group consisting of C 1  acids and ester derivatives thereof and salts thereof.  
   
     
     
         27 . The fluid of  claim 26  where in the corrosion inhibitor, the Mannich reaction product comprises the product of reaction of 
 (i) one mole of an ammonia derivative having at least one hydrogen attached to nitrogen and having no groups reactive under the conditions of reaction other than hydrogen,  
 (ii) from 1.5 to 10 moles of a carbonyl compound having at least one hydrogen atom on the carbon atom adjacent to the carbonyl group,  
 (iii) from 2 to 10 moles of an aldehyde different from the carbonyl compound, selected from the group consisting of aliphatic aldehydes having from 1 to 16 carbon atoms and aromatic aldehydes of the benzene series and having no functional groups other than aldehyde groups, and  
 (iv) from 0.6 to 24 parts by weight based on (1), (2), and (3) of a fatty acid having from 1 to 20 carbon atoms  
 at a temperature of from about 150° F. (66° C.) to about 250° F. (121° C.) for from about 1 to 16 hours.  
 
     
     
         28 . The fluid of  claim 26  where in the corrosion inhibitor, the at least one first solvent is selected from the group consisting of formic acid, formate salts, methyl formate, ethyl formate, benzyl formate, formate salts of amines, inorganic formate, and mixtures thereof.  
     
     
         29 . The fluid of  claim 26  where in the corrosion inhibitor, the components are present in the following proportions: 
 a. about 10 to 60 vol. % corrosion inhibitor base; and  
 b. about 3 to 50 vol. % solvent.  
 
     
     
         30 . The fluid of  claim 26  where the amount of corrosion inhibitor in the liquid ranges from about 0.1 to about 22 volume %.  
     
     
         31 . The fluid of  claim 26  where the corrosion inhibitor further comprises a second solvent different from the first solvent, and the second solvent is present up to about 50 volume %, based on the total corrosion inhibitor.  
     
     
         32 . A fluid for contacting a metal surface, the fluid comprising 
 A. at least one halogen acid; and    B. a corrosion inhibitor comprising: 
 a. at least one corrosion inhibitor base selected from the group consisting of: 
 i) a Mannich reaction product, and  
 ii) a nitrogen-substituted heterocycle of 6 to 10 members quaternized with at least one alkyl or aryl halide;  
 
 b. at least one first solvent selected from the group consisting of C 1  acids and ester derivatives thereof and salts thereof; and  
 c. at least one surfactant.  
   
     
     
         33 . The fluid of  claim 32  where in the corrosion inhibitor, the Mannich reaction product comprises the product of reaction of 
 (i) one mole of an ammonia derivative having at least one hydrogen attached to nitrogen and having no groups reactive under the conditions of reaction other than hydrogen,  
 (ii) from 1.5 to 10 moles of a carbonyl compound having at least one hydrogen atom on the carbon atom adjacent to the carbonyl group,  
 (iii) from 2 to 10 moles of an aldehyde different from the carbonyl compound selected from the group consisting of aliphatic aldehydes having from 1 to 16 carbon atoms and aromatic aldehydes of the benzene series and having no functional groups other than aldehyde groups, and  
 (iv) from 0.6 to 24 parts by weight based on (1), (2), and (3) of a fatty acid having from 1 to 20 carbon atoms  
 at a temperature of from about 150° F. (66° C.) to about 250° F. (121° C.) for from about 1 to 16 hours.  
 
     
     
         34 . The fluid of  claim 32  where in the corrosion inhibitor, the at least one surfactant is an esterified alcohol that has been alkoxylated.  
     
     
         35 . The fluid of  claim 34  where in the surfactant, the alcohol used to make the at least one surfactant has from about 3 to at least 22 carbon atoms.  
     
     
         36 . The fluid of  claim 32  where in the corrosion inhibitor, the at least one solvent is selected from the group consisting of formic acid, formate salts, methyl formate, ethyl formate, benzyl formate, formate salts of amines, inorganic formate, and mixtures thereof.  
     
     
         37 . The fluid of  claim 32  where in the corrosion inhibitor, the components are present in the following proportions: 
 a. about 10 to 60 vol. % corrosion inhibitor base;  
 b. about 3 to 50 vol. % solvent; and  
 c. about 5 to 50 vol. % surfactant.  
 
     
     
         38 . The fluid of  claim 32  where the amount of corrosion inhibitor in the liquid ranges from about 0.1 to about 22 volume %.  
     
     
         39 . The fluid of  claim 32  where the corrosion inhibitor further comprises a second solvent different from the first solvent, and the second solvent is present up to about 50 volume %, based on the total corrosion inhibitor.