Conversion coating and method of making

Patent metadata

Field	Value
Publication number	US-10676828-B2
Application number	US-201715694106-A
Country	US
Kind code	B2
Filing date	Sep 1, 2017
Priority date	Sep 1, 2016
Publication date	Jun 9, 2020
Grant date	Jun 9, 2020

Abstract

A composite can include a substrate and a conversion coating overlying the substrate and comprising at least one of a zirconium oxide, a hafnium oxide, or a combination thereof. The conversion coating can be formed from a zirconia or hafnia-based complex obtained by reacting at least one of a zirconium ion source, a hafnium ion source, or a combination thereof, with a chelating compound in a reaction and another chelating compound in another reaction.

First claim

The invention claimed is:

1. A composite comprising:
a substrate comprising a metal backing underlying a metal surface comprising zinc; and
a conversion coating overlying the substrate and comprising at least one of a zirconium oxide, a hafnium oxide, or a combination thereof;
the conversion coating formed from a zirconia or hafnia-based complex obtained by reacting a zirconium ion source, a hafnium ion source, or a combination thereof, with a first chelating compound in a first reaction and a second chelating compound in a subsequent second reaction, wherein at least one of the first and second chelating compound includes at least one of an ethylene diamine, N,N,N′,N′-tetrakis(2-hydroxypropyl)ethylene diamine, a glycinate, an aspartic acid, an aminopolycarboxylate nicotianamine, an amino acid glycine, a 1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid (BAPTA), a 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), an ethylene glycol-bis(β-aminoethyl ether)-N,N,N′,N′-tetraacetic acid (EGTA), a nitrilotriacetic acid (NTA), an iminodiacetic acid (IDA), or a diethylenetriaminepentaacetic acid (DTPA).

2. The composite of claim 1 , wherein the second chelating compound includes at least one of an ethylene diamine or a N,N,N′,N′-tetrakis(2-hydroxypropyl)ethylene diamine.

3. The composite of claim 1 , wherein the zirconia or hafnia-based complex is in a solution having a pH of at least 1.

4. The composite of claim 1 , wherein the zirconia or hafnia-based complex is in a solution having a pH of at most 11.

5. The composite of claim 1 , wherein the zirconia or hafnia-based complex is in a solution having a pH in a range of 1 to 11.

6. The composite of claim 1 , wherein the zirconium ion source includes a salt comprising a zirconium(IV) fluoride hydrate, a zirconium oxynitrate, or combinations thereof.

7. The composite of claim 1 , wherein the metal surface comprises a steel-based metal, alumina, zinc, or a combination thereof.

8. The composite of claim 1 , wherein the metal backing includes an aluminum, an iron, any alloy thereof, or an combination thereof.

9. The composite of claim 8 , wherein the metal backing includes an iron-based alloy.

10. The composite of claim 1 , wherein the composite exhibits a corrosion resistance R t in a range of 3500 to 10000 Ω·cm 2 , measured at 0.01 Hz.

11. The composite of claim 1 , wherein the composite exhibits a peel strength in a range of 140 to 250 N.

12. A composite comprising:
a substrate comprising a metal backing underlying a metal surface comprising zinc; and
a conversion coating overlying the substrate and comprising at least one of a zirconium oxide, a hafnium oxide, or a combination thereof;
the composite exhibiting a corrosion resistance R t of at least 3000 Ω·cm 2 , measured at 0.01 Hz; and
the composite exhibiting a peel strength of at least 140 N, the conversion coating formed from a zirconia or hafnia-based complex obtained by reacting a zirconium ion source, a hafnium ion source, or a combination there, with a first chelating compound in a first react and a second chelating compound in a subsequent second reaction wherein at least one of the first and second chelating compounds includes at least one of an ethylene diamine, N,N,N′,N′-tetrakis(2-hydroxypropyl)ethylene diamine, a glycinate, an aspartic acid, an aminopolycarboxylate nicotianamine, an amino acid glycine, a 1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid (BAPTA), a 1,4,7,10-tetraazacyclodecane-1,4,7,10-tetraacetic acid (DOTA), an ethylene glycol-bis(β-aminoethyl ether)-N,N,N′,N′-tetraacetic acid (EGTA), a nitrilotriacetic acid (NTA), an iminodiacetic acid (IDA), or a diethylenetriaminepentaacetic acid (DTPA).

13. The composite of claim 1 , wherein at least one of the first and second chelating compound includes N,N,N′,N′-tetrakis(2-hydroxypropyl)ethylene diamine.

14. The composite of claim 1 , wherein at least one of the first and second chelating compound includes a glycinate.

15. The composite of claim 1 , wherein at least one of the first and second chelating compound includes an aspartic acid.

16. The composite of claim 1 , wherein at least one of the first and second chelating compound includes an aminopolycarboxylate nicotianamine.

17. The composite of claim 1 , wherein at least one of the first and second chelating compound includes an amino acid glycine.

18. The composite of claim 1 , wherein at least one of the first and second chelating compound includes a 1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid (BAPTA).

19. The composite of claim 1 , wherein at least one of the first and second chelating compound includes a 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA).

20. The composite of claim 1 , wherein at least one of the first and second chelating compound includes an ethylene glycol-bis(β-aminoethyl ether)-N,N,N′,N′-tetraacetic acid (EGTA).

Assignees

• Saint Gobain Performance Plastics Corp

Inventors

• Dadvand Nazila
• Mekhilef Nafih
• Jiang Yi
• White Raymond J

Classifications

• C23C22/62

  Treatment of iron or alloys based thereon · CPC title

• C23C22/05 Primary

  using aqueous solutions · CPC title

• C23C22/44

  containing also fluorides or complex fluorides · CPC title

• C23C22/72

  Treatment of iron or alloys based thereon · CPC title

• C23C22/74

  for obtaining burned-in conversion coatings · CPC title