2-Substituted Imidazole and Benzimidazole Corrosion Inhibitors

Patent metadata

Field	Value
Publication number	US-2016348252-A1
Application number	US-201615166527-A
Country	US
Kind code	A1
Filing date	May 27, 2016
Priority date	May 28, 2015
Publication date	Dec 1, 2016
Grant date	—

Abstract

Disclosed are methods of using nitrogen-containing compounds as corrosion inhibitors. The present method is used to inhibit corrosion of a metal surface in contact with an aqueous system using 2-substituted imidazoles and 2-substituted benzimidazoles, and provides enhanced protection against corrosion of metals in the aqueous system. The method comprises the use of corrosion inhibitors that are generally resistant to halogen attack and provide good corrosion resistance in the presence of oxidizing halogen-based biocides. Formulations comprising 2-substituted imidazoles and 2-substituted benzimidazoles are also disclosed.

First claim

1 . A method for inhibiting corrosion of a metal surface in contact with an aqueous system. The method comprises adding to the aqueous system a compound of formula (I),

wherein each X is the same or different, and is selected from the group consisting of hydrogen, C 1 -C 16 alkyl, aryl, C 2 -C 16 alkenyl, C 2 -C 16 alkynyl, heteroaryl, C 3 -C 8 cycloalkyl, benzyl, alkylheteroaryl, halogen, halosubstituted alkyl, amino, aminoalkyl, cyano, alkoxy, hydroxyl, thiol, alkylthio, carbonyl, nitro, phosphoryl, phosphonyl, and sulfonyl;
Y is selected from the group consisting of hydroxyl, halogen, oxo, alkoxy, thiol, alkylthio, amino, hydrogen, and aminoalkyl;
Z is selected from the group consisting of carbon and nitrogen;
R 1 is selected from the group consisting of hydrogen, deuterium, C 1 -C 16 alkyl, aryl, C 2 -C 16 alkenyl, alkynyl, heteroaryl, C 3 -C 8 cycloalkyl, benzyl, alkylheteroaryl, halogen, hydroxyl, and carbonyl;
R 2 and R 3 are selected from the group consisting of hydrogen, halogen, hydroxyl, aryl, phenyl, heteroaryl, benzyl, alkylheteroaryl, carbonyl, C 2 -C 16 alkenyl, C 2 -C 16 alkynyl, C 3 -C 8 cycloalkyl, and C 1 -C 16 alkyl; and
m is 1, 2, 3, or 4; or
a salt thereof.

2 . The method of claim 1 , wherein Z is carbon.

3 . The method of claim 1 , wherein the compound of formula (I) is

4 . The method of claim 1 , wherein the compound of formula (I) is

wherein Me is methyl.

5 . The method of claim 1 , wherein the metal surface comprises copper or a copper alloy.

6 . The method of claim 1 , wherein the aqueous system comprises an oxidizing halogen compound.

7 . The method of claim 1 , wherein the aqueous system is a cooling water system.

8 . The method of claim 1 , wherein the metal has a corrosion rate of less than about 0.1 mpy.

9 . A method for inhibiting corrosion of a metal surface in contact with an aqueous system comprising an oxidizing halogen compound, the method comprising adding to the aqueous system a compound of formula (II),

wherein each of X and Y is the same or different, and is selected from the group consisting of hydrogen, C 1 -C 16 alkyl, aryl, C 2 -C 16 alkenyl, C 2 -C 16 alkynyl, heteroaryl, C 3 -C 8 cycloalkyl, benzyl, alkylheteroaryl, halogen, halosubstituted alkyl, amino, aminoalkyl, cyano, alkoxy, hydroxyl, thiol, alkylthio, carbonyl, nitro, phosphoryl, phosphonyl, and sulfonyl;
R is selected from the group consisting of hydrogen, deuterium, C 1 -C 16 alkyl, aryl, C 2 -C 16 alkenyl, C 2 -C 16 alkynyl, heteroaryl, C 3 -C 8 cycloalkyl, benzyl, alkylheteroaryl, halogen, hydroxyl, and carbonyl;
m is 1, 2, 3, or 4; and
n is 1, 2, 3, or 4; or
a salt thereof.

10 . The method of claim 9 , wherein the compound of formula (II) is

11 . The method of claim 9 , wherein the compound of formula (II) is

wherein Me is methyl.

12 . The method of claim 9 , wherein the compound of formula (II) is

13 . The method of claim 9 , wherein the compound of formula (II) is

14 . The method of claim 9 , wherein the metal surface comprises copper or a copper alloy.

15 . The method of claim 9 , wherein the aqueous system is a cooling water system.

16 . The method of claim 9 , wherein the compound of formula (II) is added to the aqueous system at a dosage of from about 0.01 ppm to about 100 ppm.

17 . The method of claim 9 , wherein the metal has a corrosion rate of about 0.1 mpy car less.

18 . A formulation for inhibiting corrosion of a metal surface in contact with an aqueous system, the formulation comprising a compound of formula (I) or (II), a phosphoric acid, and a phosphinosuccinic oligomer.

19 . The formulation of claim 18 , wherein the formulation further comprises a fluorescent organic compound.

20 . The formulation of claim 19 , wherein the fluorescent organic compound is selected from the group consisting of Rhodamine, a derivative of Rhodamine, all acridine dye, fluorescein, a derivative of fluorescein, and combinations thereof.

Assignees

• Ecolab Usa Inc

Inventors

• Rane Deepak
• Seetharaman Jothibasu
• Atkins Jeffery M
• Harbindu Anand
• Anant Piyush
• Sivaswamy Vaideeswaran
• Cheruku Pradeep

Classifications

• C07D235/12

  Radicals substituted by oxygen atoms · CPC title

• C23F11/149 Primary

  Heterocyclic compounds containing nitrogen as hetero atom · CPC title

• C07D401/04

  directly linked by a ring-member-to-ring-member bond · CPC title

• C02F2303/08

  Corrosion inhibition · CPC title

• C02F2103/023

  Water in cooling circuits · CPC title