Liquid product for stainless-steel corrosion remediation

Patent metadata

Field	Value
Publication number	US-11008536-B2
Application number	US-201916352171-A
Country	US
Kind code	B2
Filing date	Mar 13, 2019
Priority date	Mar 13, 2019
Publication date	May 18, 2021
Grant date	May 18, 2021

Abstract

A concentrate aqueous composition for removing Type I and Type III rouge from various stainless-steel items. The liquid composition comprises oxalic acid, a phosphonic acid, and various amines. The use of an amine has been found to provide synergistic results in removal of the noted types of corrosion from various stainless-steel items that include medical instruments, machines, equipment, pipes, tools, mixing and storage vessels, and the like.

First claim

What is claimed is:

1. A concentrated stainless steel liquid corrosion remediation composition, comprising:
oxalic acid or an oxalic acid dihydrate, or both, in an amount of at least about 0.2 wt. % to about 10 wt. %;
one or more phosphonic acids comprising at least one of hydroxyethylidene diphosphonic acid (HEDP), diethylenetriamine penta(methylene phosphonic acid) (DTPMP), bis(hexamethylene triamine penta(methylene phosphonic) acid (BHMTPMPA), aminotrimethylene phosphonic acid (ATMP), or 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTC), in an amount of from about 10 wt. % to about 30 wt. %;
one or more amines comprising at least one of monoethanolamine (MEA), monoisopropnaolamine (MIPA), aminomethylpropanol (AMP), aminomethyl propanediol (AMPD), or triethanolamine (TEA), in an amount from about 3 wt. % to about 20 wt. %;
optionally one or more hydrotrope surfactants, and optionally one or more surfactants that is capable of wetting, dispersing, or emulsifying said concentrate composition;
a solvent system; and
wherein said weight percent amounts are based on the 100 total parts by weight of said concentrate composition.

2. The concentrated stainless steel liquid corrosion remediation composition of claim 1 , wherein when utilized the total amount of said one or more hydrotrope surfactants is from about 0.4 wt. % to about 5 wt. %; and
wherein when utilized the total amount of said one or more wetting surfactants is from about 0.4 wt. % to about 5 wt. %.

3. The concentrated stainless steel liquid corrosion remediation composition of claim 1 , wherein the amount of said oxalic acid or an oxalic acid dihydrate, or both, is from about 0.5 wt. % to about 5.0 wt. %; wherein the amount of said one or more amines is from about 4 wt. % to about 15 wt. %; wherein the amount of said one or more phosphonic acids is from about 14 wt. % to about 25 wt. %; wherein the amount of said one or more hydrotrope surfactants is from about 0.6 wt. % to about 2.0 wt. %; and wherein the amount of said one or more wetting surfactants is from about 0.6 wt. % to about 2.0 wt. %.

4. The concentrated stainless steel liquid corrosion remediation composition of claim 3 , wherein the amount of said oxalic acid or an oxalic acid dihydrate, or both, is from about 0.8 wt. % to about 1.2 wt. %; wherein the amount of said one or more phosphonic acids is from about 16 wt. % to about 20 wt. %; wherein the amount of said one or more amines is from about 5 wt. % to about 13 wt. %; and comprising said hydrotrope surfactant.

5. The concentrated stainless steel liquid corrosion remediation composition of claim 3 , comprising said one or more hydrotropes, wherein said one or more hydrotrope surfactants comprises sodium caprylyl sulfonate or sodium xylene sulfonate, or both.

6. The concentrated stainless steel liquid corrosion remediation composition of claim 5 , comprising said one or more wetting surfactants comprising sodium alkyl sulfate having from about 6 to about 18 carbon atoms.

7. The concentrated stainless steel liquid corrosion remediation composition of claim 4 , wherein said phosphonic acid comprises said hydroxyethylidene diphosphonic acid.

8. The concentrated stainless steel liquid corrosion remediation composition of claim 1 , wherein said concentrated stainless steel liquid corrosion remediation composition is capable of removing Type I Rouge.

9. The concentrated stainless stool liquid corrosion remediation composition of claim 2 , wherein said concentrated stainless steel liquid corrosion remediation composition is capable of removing Type I Rouge.

10. The concentrated liquid corrosion remediation composition of claim 4 , wherein said concentrated stainless steel liquid corrosion remediation composition is capable of removing Type I Rouge.

11. The concentrated stainless steel liquid corrosion remediation composition of claim 1 , wherein said concentrated stainless steel liquid corrosion remediation composition is capable of removing Type III Rouge.

12. The concentrated liquid corrosion remediation composition of claim 3 , wherein said concentrated stainless steel liquid corrosion remediation composition is capable of removing Type Ill Rouge.

13. The concentrated stainless steel liquid corrosion remediation composition of claim 3 , wherein said concentrated stainless steel liquid corrosion remediation composition is capable of removing Type Ill Rouge.

14. A concentrated stainless liquid corrosion remediation composition comprising:
an oxalic acid or an oxalic acid dihydrate, or both, in an amount of at least about 0.2 wt. % to about 10 wt. %;
one or more phosphonic acids comprising at least one of hydroxyethylidene diphosphonic acid (HEDP), diethylenetriamine penta(methylene phosphonic acid) (DTPMP), bis(hexamethylene triamine penta(methylene phosphonic) acid (BHMTPMPA), aminotrimethylene phosphonic acid (ATMP), or 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTC), in an amount of from about 10 wt. % to about 30 wt. %;
one or more amines comprising at least one of monoethanolamine (MEA), monoisopropnaolamine (MIPA), aminomethylpropanol (AMP), aminomethyl propanediol (AMPD), or triethanolamine (TEA), wherein the total amount of said one or more amines is from about 3 wt.% to about 20 wt.%;
a solvent system; and
one or more hydrotrope surfactants;
wherein said weight percent amounts are based upon 100 total parts by weight of said concentrated composition.

15. The concentrated stainless steel liquid remediation composition of claim 14 , wherein the amount of said one or more hydrotrope surfactants is from about 0.4 wt.% to about 5 wt. %.

16. The concentrated stainless steel liquid corrosion remediation composition of claim 15 , wherein the amount of said oxalic acid or an oxalic acid dihydrate, or both, is from about 0.5 wt. % to about 5.0 wt. %; wherein the amount of said one or more amines is from about 4 wt. % to about 15 wt. %; wherein the amount of said one or more phosphonic acids is from about 14 wt. % to about 25 wt. %; and wherein the amount of said one or more hydrotrope surfactants is from about 0.6 to about 2.0 wt. %.

17. A concentrated stainless steel liquid corrosion remediation composition comprising:
oxalic acid or an oxalic acid dihydrate, or both, in an amount of at least about 0.2 wt. % to about 10 wt. %;
one or more phosphonic acids comprising at least one of hydroxyethylidene diphosphonic acid (HEDP), diethylenetriamine penta(methylene phosphonic acid) (DTPMP), bis(hexamethylene triamine penta(methylene phosphonic) acid (BHMTPMPA), aminotrimethylene phosphonic acid (ATMP), or 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTC), in an amount of from about 10 wt. % to about 30 wt. %;
one or more amines comprising at least one of monoethanol amine (MEA), monoisopropanol amine (MIPA), aminomethyl propanol (AMP), aminomethyl propanediol (AMPD), or triethanolamine (TEA), in an amount from about 3 wt. % to about 20 wt. %;
a solvent system ; and
one or more surfactants that are capable of wetting, dispersing, or emulsifying said concentrate composition;
wherein said weight percent amounts are based upon 100 total parts by weight of said concentrated composition.

18. The concentrated stainless steel liquid corrosion remediation composition of claim 17 , wherein the amount of said one or more wetting surfactants is from about 0.4 wt. % to about 5 wt. %.

19. The concentrated stainless steel liquid corrosion remediation composition of claim 18 , wherein the amount of said oxalic acid or an oxalic acid dihydrate, or both, is from about 0.5 wt.

Assignees

• American Sterilizer Co

Inventors

• Smith Thomas William
• Kaiser Nancy-Hope Elizabeth
• Fix Kathleen Ann

Classifications

• C11D7/50

  Solvents · CPC title

• C11D7/36

  containing phosphorus · CPC title

• C11D7/3218

  Alkanolamines or alkanolimines · CPC title

• C11D7/265 Primary

  Carboxylic acids or salts thereof · CPC title

• C11D3/43

  Solvents · CPC title