Purine-Based Corrosion Inhibitors

Patent metadata

Field	Value
Publication number	US-2016348253-A1
Application number	US-201615166549-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 biodegradable heterocyclic compounds of relatively low toxicity as corrosion inhibitors. The present method is used to inhibit corrosion of a metal surface in contact with an aqueous system using compounds comprising a purine structure, and provides enhanced protection against corrosion of metals in aqueous systems. 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 purine-based compounds are also disclosed.

First claim

1 . 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 (I),

wherein X is selected from the group consisting of —NH 2 , —SH, and halogen;
Y is selected from the group consisting of hydrogen, aryl, heteroaryl, C 1 -C 16 alkyl, C 2 -C 16 alkenyl, C 2 -C 16 alkynyl, C 3 -C 8 cycloalkyl, benzyl, alkylheteroaryl, halogen, halosubstituted alkyl, amino, aminoalkyl, cyano, aikoxy, hydroxyl, thiol, alkylthio, carbonyl, nitro, phosphoryl, phosphoryl, and sulfonyl;
R 1 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; and
R 2 is selected from the group consisting of hydrogen, aryl, heteroaryl, henzyl, alkylheteroaryl, C 2 -C 16 alkenyl, C 2 -C 16 alkynyl, C 3 - 8 cycloalkyl, and C 1 -C 16 alkyl; or
a salt thereof.

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

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

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

6 . The method of claim 1 , wherein the oxidizing halogen is selected from the group consisting of hypochlorite, chlorine, bromine, hypobromite, chlorine dioxide, iodine, hypoiodous acid, hypobromous acid, halogenated hydantoins, or combinations thereof.

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 about 0.2 mpy or less.

9 . The method of claim 1 , wherein the compound of formula (I) is added to the aqueous system at a dosage of from about 0.01 ppm to about 100 ppm.

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

wherein X is selected from the group consisting of NH, O, and S;
Y is selected from the group consisting of hydrogen, aryl, heteroaryl, C 1 -C 16 C 2 -C 16 alkenyl, C 2 -C 1 -C 16 alkynyl, C 3 -C 8 benzyl, alkylheteroaryl, halogen, halosubstituted alkyl, amino, aminoalkyl, cyano, alkoxy, hydroxyl, thiol, alkylthio, carbonyl, nitro, phosphoryl, phosphonyl, and sulfonyl;
R 1 is selected from the group consisting of hydrogen, aryl, heteroaryl, C 1 -C 16 alkyl, C 2 -C 16 Amyl, C 2 -C 16 alkynyl, C 3 -C 8 cycloalkyl, benzyl, alkyiheteroaryl, halogen, halosubstituted alkyl, amino, aminoalkyl, cyano, alkoxy, hydroxyl, thiol, alkylthio, carbonyl, nitro, phosphoryl, phosphonyl, and sulfonyl;
R 2 is selected from the group consisting of hydrogen, deuterium, C 1 -C 16 alkyl, aryl, alkenyl, C 2 -C 16 alkynyl, heteroaryl, C 3 -C 8 cycloalkyl, benzyl, alkylheteroaryl, halogen, hydroxyl, and carbonyl;
R 3 is selected from the group consisting of hydrogen, aryl, heteroaryl, benzyl, alkylheteroaryl, alkenyl, C 2 -C 16 alkynyl, C 3 -C 8 cycloalkyl, and C 1 -C 16 alkyl; and
m is an integer of from 0 to 9; or
a salt thereof.

11 . The method of claim 10 , wherein R 1 is selected from the group consisting of phenyl, naphthyl, anthracyl, furanyl, benzofuranyl, thiophenyl, benzothiophenyl, pyridyl, pyrrolyl, pyrazolyl, imidazolyl, 1,2,3-triazolyl, 1,2,4-triazolyl, isoxazolyl, oxazolyl, isothiazolyl, thiazolyl, pyrazinyl, triazinyl, indolyl, quinolinyl, isoquinolinyl, benzimidazolyl, benzoxazolinyl, and benzothiazolinyl.

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

13 . The method of claim 10 , wherein he compound of formula (II) is

14 . The method of claim 10 , wherein the aqueous system comprises an oxidizing halogen compound.

15 . The method of claim 10 , wherein the metal surface comprises copper or a copper alloy.

16 . The method of claim 10 , wherein the metal surface comprises mild steel.

17 . The method of claim 10 , wherein the metal has a corrosion rate of about 0.1 mpy or 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, an acridine dye, fluorescein, a derivative of fluorescein, and combinations thereof.

Assignees

• Ecolab Usa Inc

Inventors

• Harbindu Anand
• Seetharaman Jothibasu
• Rane Deepak
• Sivaswamy Vaideeswaran

Classifications

• C02F5/12

  containing nitrogen (C02F5/14 takes precedence) · CPC title

• C02F2103/28

  from the paper or cellulose industry · CPC title

• C23F11/149 Primary

  Heterocyclic compounds containing nitrogen as hetero atom · CPC title

• C02F2103/023

  Water in cooling circuits · CPC title

• C02F1/76

  with halogens or compounds of halogens {(C02F1/4674 takes precedence)} · CPC title