Non-triazole imidazoline and amide compounds and methods for inhibiting corrosion in industrial water treatment

Abstract

Methods of treating aqueous systems with treatment compositions including non-triazole derivatives of imidazoline and/or amide compounds are provided that are effective to inhibit corrosion of corrodible metal surfaces in the aqueous systems. The non-triazole imidazoline and/or amide compounds show comparable or better corrosion inhibition as compared to conventional triazole corrosion inhibitors, and have low toxicity and good stability in the presence of halogens such as halogen-containing biocides or free chlorine.

What is claimed is: 
     
         1 . A method of inhibiting corrosion of a corrodible metal surface that contacts a water stream in a water system, the method comprising:
 during a first period of time, introducing into the water stream a treatment composition in a first amount, the treatment composition including at least one of (i) at least one non-triazole derivative of imidazoline compound comprising at least one carboxylic or carboxylate group, at least two nitrogen atoms, and an alkyl group, and (ii) at least one amide compound comprising at least one carboxylic or carboxylate group, at least two nitrogen atoms, and an alkyl group; and   after the first period of time, introducing the treatment composition in a second amount that is lower than the first amount.   
     
     
         2 . The method of  claim 1 , wherein the first amount is sufficient so that the at least one non-triazole derivative of imidazoline compound or the at least one amide compound is present in the water in an amount in a range of from 5 ppm to 500 ppm. 
     
     
         3 . The method of  claim 1 , wherein the second amount is sufficient so that the at least one non-triazole derivative of imidazoline compound or the at least one amide compound is present in the water in an amount in a range of from 0.01 ppm to 5 ppm. 
     
     
         4 . The method of  claim 1 , wherein, during a second period of time after the first period of time, and before the treatment composition is introduced in the second amount, none of the treatment composition is introduced into the water stream. 
     
     
         5 . The method of  claim 1 , wherein the treatment composition includes the non-triazole derivative of imidazoline compound, and the non-triazole derivative has a structure corresponding to Formula (I): 
       
         
           
           
               
               
           
         
         where R is a hydrocarbon group having in a range of 7 to 20 carbon atoms. 
       
     
     
         6 . The method of  claim 1 , wherein the treatment composition includes the amide compound, and the amide compound has a structure corresponding to Formula (II): 
       
         
           
           
               
               
           
         
         where R is a hydrocarbon group having 7 to 20 carbon atoms, each R′ is independently H or C, R″ is N, a nitrogen-containing group, O, C, OH, or COOH, n is in a range of 1 to 20, m is in a range of 1 to 20, and 1 is in a range of 1 to 20. 
       
     
     
         7 . The method of  claim 1 , wherein the at least one carboxylate group of the non-triazole derivative is a carboxylate ether, and wherein the at least one carboxylate group of the amide compound is a carboxylate ether. 
     
     
         8 . The method of  claim 1 , wherein the treatment composition includes the non-triazole derivative of imidazoline compound, and the non-triazole derivative is sodium dicarboxylethyl coco phosphoethyl imidazoline. 
     
     
         9 . The method of  claim 1 , wherein the treatment composition includes the amide compound, and the amide compound is selected from the group consisting of disodium cocoamphodiacetate, sodium cocoamphoacetate, and disodium lauroamphodiacetate. 
     
     
         10 . The method of  claim 1 , wherein the at least one non-triazole derivative of imidazoline compound or the at least one amide compound is introduced into the water stream in an amount of from 0.01 ppm to 100 ppm. 
     
     
         11 . The method of  claim 1 , wherein the at least one non-triazole derivative of imidazoline compound or the at least one amide compound is introduced into the water stream in an amount of from 1 ppm to 3 ppm. 
     
     
         12 . The method of  claim 1 , wherein the corrodible metal surface is a yellow metal surface. 
     
     
         13 . The method of  claim 1 , wherein the water system is a mixed metal system including a yellow metal surface and at least one of a stainless steel surface, mild steel surface, galvanized steel surface, a ferrous steel surface, and an aluminum surface. 
     
     
         14 . A method of treating a corrodible metal surface that contacts a water stream in a water system with a corrosion inhibition treatment composition that includes at least one of (i) at least one non-triazole derivative of imidazoline compound comprising at least one carboxylic or carboxylate group, at least two nitrogen atoms, and an alkyl group, and (ii) at least one amide compound comprising at least one carboxylic or carboxylate group, at least two nitrogen atoms, and an alkyl group, the method comprising:
 during a stage when the corrodible metal surfaces are free from any protective film that is formed from the corrosion inhibition treatment composition, introducing the corrosion inhibition treatment composition into the water stream in a first amount for a first period of time, the first amount being is sufficient so that the at least one non-triazole derivative of imidazoline compound or the at least one amide compound is present in the water in an amount in a range of from 5 ppm to 500 ppm.   
     
     
         15 . The method of  claim 14 , wherein the first period of time is at least 8 hours. 
     
     
         16 . The method of  claim 14 , wherein the first period of time is of a sufficient duration so that a protective film is formed on the corrodible metal surfaces. 
     
     
         17 . The method of  claim 14 , wherein the protective film has a thickness in a range of 1 nm to 150 nm. 
     
     
         18 . The method of  claim 14 , wherein, at the end of the first period of time, the corrodible metal surface exhibits a contact angle that is in a range of from 65 to 85 degrees.