Thin corrosion protective coatings incorporating polyamidoamine polymers

Patent metadata

Field	Value
Publication number	US-12365812-B2
Application number	US-202117461100-A
Country	US
Kind code	B2
Filing date	Aug 30, 2021
Priority date	Apr 15, 2015
Publication date	Jul 22, 2025
Grant date	Jul 22, 2025

Abstract

Anti-corrosion metal pretreatment compositions comprising a Group IVB metal, a Group IB metal and polyamidoamine polymers; replenisher compositions for the metal pretreatment compositions; methods of making the metal pretreatment compositions; methods of forming an anti-corrosion Group IVB oxide coating on at least one metal substrate surface by contacting the surface with the metal pretreatment composition; and coated metal substrates having anti-corrosion coatings deposited on the metal substrates from chrome VI free, anti-corrosion metal pretreatment compositions having enhanced corrosion resistance of the Group IVB metal oxide coatings and adhesion of the anti-corrosion and primer coating layers to metal substrates.

First claim

We claim:

1. An anti-corrosion metal pretreatment composition comprising components:
a) from 10 to 2000 ppm of dissolved Group IVB metal;
b) from 1 to 50 ppm of dissolved copper;
c) from 1 to 5000 ppm of at least one nitrogen containing organic polyamidopolyamine polymer which is a reaction product resulting from a polymerization reaction of alkyldiamines, polyamines and/or polyalkylpolyamines with a carboxylic acid or carboxylic acid derivative, dissolved and/or dispersed in the composition and comprising a plurality of organic amide and amine functional groups and optionally imidazoline functional groups, wherein the at least one polyamidopolyamine polymer comprises a mixture of two polyamidopolyamine polymers, wherein a first polyamidopolyamine polymer has a number average molecular weight of from about 200 to 400 Daltons and a second polyamidopolyamine polymer, different from the first, has a weight average molecular weight ranging from 200 to 10,000 Daltons; and
d) water;
said anti-corrosion metal pretreatment composition having a pH of from 2 to 6.

2. The anti-corrosion metal pretreatment composition of claim 1 , wherein component c) has a viscosity at 25° C. of 1 to 400 poise.

3. The anti-corrosion metal pretreatment composition of claim 1 , wherein one or more of the at least one nitrogen containing organic polyamidopolyamine polymer comprises a plurality of primary and/or tertiary amine functional groups in addition to the amide functional groups.

4. The anti-corrosion metal pretreatment composition of claim 1 , wherein one or more of the at least one nitrogen containing organic polyamidopolyamine polymer has an amine value in a range of 100 to 1000 mg KOH/gram.

5. The anti-corrosion metal pretreatment composition of claim 1 , wherein component c) remains stably dissolved and/or dispersed in the composition against spontaneous separation or segregation of bulk phases that is perceptible with normal unaided human vision during storage at 25° C. for at least 10 days after preparation of the pretreatment composition.

6. The anti-corrosion metal pretreatment composition of claim 1 , wherein the Group IVB metal is zirconium and component c) comprises at least one branched polyamidopolyamine polymer.

7. The anti-corrosion metal pretreatment composition of claim 1 , wherein at least some of the organic amide functional groups in one or more of the at least one nitrogen containing organic polyamidopolyamine polymer have dehydrated to the imidazoline functional groups.

8. The anti-corrosion metal pretreatment composition of claim 1 , wherein one or more of the at least one nitrogen containing organic polyamidopolyamine polymer comprises tertiary nitrogen atoms.

9. The anti-corrosion metal pretreatment composition of claim 1 , wherein one or more of the at least one nitrogen containing organic polyamidopolyamine polymer has multiple branches.

10. The anti-corrosion metal pretreatment composition of claim 5 , wherein one or more polyamidoamine polymers according to the general formula (I) are present in component c):

where, independently for each of said one or more polyamidoamine polymers:
R1 represents a hydrogen or an organic moiety;
R2 represents a hydrogen or an organic moiety;
m represents a number ranging from 1 to 8; n represents a number ranging from 1 to 8; x represents a number ranging from 1 to 40; y represents a number ranging from 2 to 80; and z represents a number ranging from 2 to 500.

11. The anti-corrosion metal pretreatment composition of claim 1 , wherein said coating composition further comprises from 5 to 200 ppm of free fluoride and has a pH of 3.6 to 5.5.

12. The anti-corrosion metal pretreatment composition of claim 1 , wherein said coating composition further comprises at least 3000 ppm of nitrate ions.

13. The anti-corrosion metal pretreatment composition of claim 1 , wherein component c) comprises at least one polyamidoamine polymer which is a reaction product resulting from a polymerization reaction of alkyldiamines, polyamines and/or polyalkylpolyamines with a carboxylic acid or carboxylic acid derivative having a reactive carboxylate group and at least one additional amine reactive functional group.

14. The anti-corrosion metal pretreatment composition of claim 13 , wherein said polyamines are selected from the group consisting of polyethylene polyamines, polypropylene polyamines, polybutylene polyamines, polypentylene polyamines, polyhexylene polyamines, and mixtures thereof.

15. The anti-corrosion metal pretreatment composition of claim 13 , wherein the carboxylic acid or carboxylic acid derivative is selected from the group consisting of fatty acid dimers, tall oil fatty acids, and mixtures thereof.

16. The anti-corrosion metal pretreatment composition of claim 1 , wherein component c) comprises at least one polyamidoamine polymer which is a reaction product resulting from a polymerization reaction of:
1) at least one carboxylic acid selected from the group consisting of a C 6 to C 24 monocarboxylic fatty acid, a C 6 to C 20 dicarboxylic acid, a C 12 to C 40 fatty acid dimer, and mixtures thereof; and
2) at least one polyamine having at least two amine groups.

17. The anti-corrosion metal pretreatment composition of claim 16 , wherein said at least one polyamine is selected from the group consisting of diamines, tris(2-aminoethyl) amine, polyethylene polyamines, and mixtures thereof.

18. A method of making the anti-corrosion metal pretreatment composition of claim 1 comprising steps of:
a) providing a selected amount of deionized water in a bath container;
b) adding to the deionized water of step a) an amount of a source of Group IVB metal and an amount of a source of copper calculated to produce a ready-to-use bath composition comprising from 10 to 2000 ppm of dissolved Group IVB metal and from 1 to 50 ppm of dissolved copper in step d), and optionally adding an amount of a source of fluoride ions and a source of nitrate ions calculated to produce the ready-to-use bath composition comprising from 5 to 200 ppm of free fluoride and 500 ppm or greater of nitrate ions in step d);
c) dissolving and/or dispersing in the bath container after step b), an amount of said at least one nitrogen containing organic polyamidopolyamine polymer calculated to produce an amount of from 1 to 5000 ppm of said polymer present in the ready-to-use bath composition in step d), wherein said at least one nitrogen containing organic polyamidoamine polymer is the reaction product resulting from the polymerization reaction of alkyldiamines, polyamines and/or polyalkylpolyamines with a carboxylic acid or carboxylic acid derivative, and comprising a plurality of organic amide and amine functional groups and optionally imidazoline functional groups, wherein the at least one polyamidopolyamine polymer comprises the mixture of two polyamidopolyamine polymers, wherein the first polyamidopolyamine polymer has a number average molecular weight of from about 200 to 400 daltons and the second polyamidopolyamine polymer, different from the first, has a weight average molecular weight ranging from 200 to 10,000 daltons; and
d) adjusting pH of the bath composition to achieve a ready-to-use bath composition having a pH of from 2-6.

Assignees

• Henkel Ag & Co Kgaa

Inventors

• Vonk Donald Robb
• Smith Ii Thomas Sullivan
• Bobadilla Alvaro

Classifications

• C08K2003/2244

  of zirconium · CPC title

• C08K2003/085

  Copper · CPC title

• C08K3/28

  Nitrogen-containing compounds · CPC title

• C08K3/22

  of metals · CPC title

• C08K3/16

  Halogen-containing compounds · CPC title