Corrosion inhibiting compositions and methods of making and using

Patent metadata

Field	Value
Publication number	US-9605162-B2
Application number	US-201313839895-A
Country	US
Kind code	B2
Filing date	Mar 15, 2013
Priority date	Mar 15, 2013
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

A corrosion inhibiting composition includes one or more of a plurality of carriers, each having a carrier body and an organic corrosion inhibitor, such that the carrier body encapsulates the organic corrosion inhibitor, and the carrier body is formed of a degradable material. Coatings and methods for inhibiting corrosion on a metal substrate are also described herein.

First claim

What is claimed is:

1. A coating for inhibiting corrosion on a metal substrate, the coating comprising a corrosion inhibiting composition comprising:
a first plurality of carriers, each comprising a first carrier body and a first corrosion inhibitor, the first carrier body encapsulating the first corrosion inhibitor, wherein the first corrosion inhibitor is a first organic compound comprising a ring structure and wherein the first carrier body is formed of a first degradable material; and
a second plurality of carriers, each comprising a second carrier body and a second corrosion inhibitor, the second carrier body encapsulating the second corrosion inhibitor, wherein the second carrier body is formed of a second degradable material;
wherein the second corrosion inhibitor is a second organic compound comprising a ring structure, wherein the second corrosion inhibitor is different from the first corrosion inhibitor, wherein the second plurality of carriers does not include the first corrosion inhibitor and the first plurality of carriers does not include the second corrosion inhibitor, and wherein the first degradable material has a mechanical integrity which deteriorates in at least one of an alkaline condition and an acidic condition sufficient to release the first corrosion inhibitor from the first degradable material;
wherein the coating exhibits a creep value of about 0.6 mm or less according to a hot salt water test when the coating is tested at a thickness of 25 microns,
wherein the hot salt water test comprises:
cutting an X-shaped cut into a test piece of a metal substrate comprising a base material using an SK2 cutting knife having a hardness of HV 820+/−30, wherein the X-shaped cut has a cross angle from 60° to 90° and reaches the base material of the metal substrate,
immersing the test piece in a 5 wt % NaCl solution at 55° C. in a container,
sealing the container,
removing the test piece from the container after 240 hours and rinsing and wiping the test piece,
measuring a width of any rust and/or blister on the test piece in order to determine a blister width, and
attaching a 12 or 24 mm wide piece of cellophane adhesive tape to the rust and/or blister, holding the edge of the adhesive tape to form an angle of 45° between the adhesive tape and test piece, peeling off the adhesive tape, and measuring a width of any resulting peeled portion in order to determine a peeling width,
wherein the creep value is the larger of the peeling width and the blister width.

2. The coating of claim 1 , wherein the first organic compound comprises a heterocyclic compound.

3. The coating of claim 1 , wherein the first corrosion inhibitor is a chelating agent.

4. The coating of claim 2 , wherein the heterocyclic compound includes an endocyclic donor atom and an exocyclic donor atom.

5. The coating of claim 4 , wherein the exocyclic donor atom is directly bonded to a heterocyclic ring of the heterocyclic compound.

6. The coating of claim 4 , wherein the exocyclic donor atom is not directly bonded to a heterocyclic ring of the heterocyclic compound.

7. The coating of claim 2 , wherein the heterocyclic compound is selected from the group consisting of 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, 2-(benzothiazol-2-ylsulfanyl)-succinic acid, 8-hydroxyquinoline, 8-hydroxyquinaldine, and any combination thereof.

8. The coating of claim 1 , wherein the first corrosion inhibitor and the second corrosion inhibitor comprises from about 10% to about 40%, by weight, of the first plurality of carriers and the second plurality of carriers.

9. The coating of claim 8 , wherein the first corrosion inhibitor and the second corrosion inhibitor comprises from about 15% to about 35%, by weight, of the first plurality of carriers and the second plurality of carriers.

10. A coating for inhibiting corrosion on a metal substrate, the coating comprising a corrosion inhibiting composition; comprising:
a first plurality of carriers, each comprising a first carrier body and a first corrosion inhibitor, the first carrier body encapsulating the first corrosion inhibitor, wherein the first corrosion inhibitor is a first organic compound comprising a ring structure and wherein the first carrier body is formed of a first degradable material; and
a second plurality of carriers, each comprising a second carrier body and a second corrosion inhibitor, the second carrier body encapsulating the second corrosion inhibitor, wherein the second carrier body is formed of a second degradable material;
wherein the second corrosion inhibitor is a second organic compound comprising a ring structure, wherein the second corrosion inhibitor is different from the first corrosion inhibitor, wherein the second plurality of carriers does not include the first corrosion inhibitor and the first plurality of carriers does not include the second corrosion inhibitor, and wherein the first degradable material has a mechanical integrity which deteriorates in at least one of an alkaline condition and an acidic condition sufficient to release the first corrosion inhibitor from the first degradable material;

wherein the coating exhibits a creep value of about 1.6 mm or less according to a salt spray test when the coating is tested at a thickness of 25 microns,
wherein the salt spray test comprises:
cutting an X-shaped cut into a test piece of a metal substrate comprising a base material using an SK2 cutting knife having a hardness of HV 820+/−30, wherein the X-shaped cut has a cross angle from 60° to 90° and reaches the base material of the metal substrate,

affixing the test piece on a salt spray tester conforming to ASTM B117 standard, with a test chamber temperature of 35±1° C., an air saturator temperature of 47±1° C., a test chamber relative humidity of about 95%, a spraying pressure of from 70 to 180 kPa, an amount of solution collected being from 0.85 to 2.0 mL/hour for 80 cm2, and a pH of solution made by spraying of from 6.5 to 7.2, at 15° to 30° to a vertical line,
subjecting the test piece to spraying of 5.0 wt % NaCl solution for 960 hours,
rinsing the test piece to remove any corrosion product,
measuring a width of the largest swollen area of the X-shaped cut in order to determine a blister width,
after two hours at room temperature, attaching a 12 or 24 mm wide piece of cellophane adhesive tape to the test piece, holding the edge of the adhesive tape to form an angle of 45° between the adhesive tape and test piece, and peeling the tape off the test piece,
measuring a width of an area of the coating which was peeled with the tape to determine a peeling width,
wherein the creep value is the larger of the peeling width and the blister width.

11. The coating of claim 10 , wherein the first organic compound comprises a heterocyclic compound.

12. The coating of claim 10 , wherein the first corrosion inhibitor is a chelating agent.

13. The coating of claim 11 , wherein the heterocyclic compound includes an endocyclic donor atom and an exocyclic donor atom.

14. The coating of claim 13 , wherein the exocyclic donor atom is directly bonded to a heterocyclic ring of the heterocyclic compound.

15. The coating of claim 13 , wherein the exocyclic donor atom is not directly bonded to a heterocyclic ring of the heterocyclic compound.

16. The coating of claim 11 , wherein the heterocyclic compound is selected from the group consisting of 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, 2-(benzothiazol-2-ylsulfanyl)-succinic acid, 8-hydroxyquinoline, 8-hydroxyquinaldine, and any combination thereof.

17. The coating of claim 10

Assignees

• Honda Motor Co Ltd

Inventors

• Fitz Todd Andrew
• Berg Mariko Elaine

Classifications

• C09D5/086

  Organic or non-macromolecular compounds · CPC title

• Y10T428/265

  1 mil or less · CPC title

• Y10T428/31678

  Of metal · CPC title

• Y10T428/263

  Coating layer not in excess of 5 mils thick or equivalent · CPC title

• C09D7/1233 Primary

  Chemistry & Metallurgy · mapped topic