Method for coating metal surfaces of substrates and objects coated in accordance with said method

Patent metadata

Field	Value
Publication number	US-11505705-B2
Application number	US-201816119319-A
Country	US
Kind code	B2
Filing date	Aug 31, 2018
Priority date	Jul 10, 2013
Publication date	Nov 22, 2022
Grant date	Nov 22, 2022

Abstract

The invention relates to a method for coating surfaces, to a corresponding coating, and to the use of the objects coated in accordance with said method. The invention relates to a method for coating metal surfaces of substrates, comprising or consisting of the following steps: I. providing a substrate having a cleaned metal surface, II. contacting and coating metal surfaces with an aqueous composition in the form of a dispersion and/or suspension, IX. optionally rinsing the organic coating, and X. drying and/or baking the organic coating or XI. optionally drying the organic coating and coating with a coating composition of the same type or a further coating composition before a drying process and/or baking process, wherein in step II the coating is performed with an aqueous composition in the form of a dispersion and/or suspension containing 2.5 to 45 wt % of at least one non-ionic stabilized binder and 0.1 to 2.0 wt % of a gelling agent, wherein the aqueous composition has a pH value in the range of 0.5 to 7 and forms, with the cations eluted from the metal surface in the pretreatment step and/or during the contacting in step II, a coating based on an ionogenic gel.

First claim

The invention claimed is:

1. An aqueous composition containing 2.5 to 45 wt % of at least one nonionically stabilized binder and 0.1 to 2.0 wt % of a gelling agent, wherein the aqueous composition has a pH in the range of 0.5 to 7, wherein the gelling agent contains at least one anionic polysaccharide, wherein the gelling agent further contains at least one anionic polyelectrolyte selected from the group consisting of anionic polyelectrolytes having a molecular weight in the range of 500 to 1,000,000 g/mol, and wherein the aqueous composition is in a form of a dispersion, a suspension, or a combination thereof.

2. The aqueous composition according to claim 1 further containing one or more representatives selected from the group consisting of:
a) a crosslinking agent selected from the group consisting of silanes, siloxanes, phenolic resins and amines in an amount of 0.01 g/L to 50 g/L,
b) complex titanium, zirconium fluorides or a combination thereof in an amount of 0.01 g/L to 500 g/L, and
c) at least one additive selected from the group consisting of defoaming agents, pigments, biocides, dispersion aids, film-forming aids, acidic additives for adjusting the pH, basic additives for adjusting the pH, thickeners and flow control agents.

3. The aqueous composition according to claim 1 , wherein the aqueous composition is configured to contact and coat a metallic surface in the form of at least one of a dispersion and suspension.

4. The aqueous composition according to claim 3 , wherein a coating is formed and is based on an ionogenic gel.

5. The aqueous composition according to claim 4 , wherein the coating comprises at least one of oxides, hydroxides, carbonates, phosphates, phosphosilicates, silicates, sulfates, organic polymers including copolymers and derivatives thereof, waxes, compounded particles, and mixtures thereof.

6. The aqueous composition according to claim 1 , wherein the aqueous composition further comprises film-forming binders selected from the group consisting of polyacrylates, polyurethanes, polyepoxides, and hybrids thereof.

7. The aqueous composition according to claim 1 , wherein the aqueous composition further comprises film-forming binders selected from the group consisting of organic polymers, copolymers based on polyvinyl alcohols, polyvinyl acetates, polybutyl acrylates, and other acrylic acid esters and are present in amounts of at least 50 wt % in the aqueous composition.

8. The aqueous composition according to claim 7 , wherein the aqueous composition further comprises film forming aids, and wherein a weight ratio of the film-forming binders to the film-forming aids is in the range of from 100:1.4 to 100:1.

9. The aqueous composition according to claim 1 , wherein the aqueous composition contains at least one type of cations selected from the group consisting of cations based on salts with a cationic effect selected from the group consisting of melamine salts, nitroso salts, oxonium salts, ammonium salts, salts with quaternary nitrogen cations, salts of ammonium derivatives, and metal salts of Al, B, Ba, Ca, Cr, Co, Cu, Fe, Hf, In, K, Li, Mg, Mn, Mo, Na, Nb, Ni, Pb, Sn, Ta, Ti, V, W, Zn, and Zr.

10. The aqueous composition according to claim 1 , wherein the aqueous composition contains at least one of a complexing agent for metal cations and a polymer that is modified for complexing metal cations.

11. The aqueous composition according to claim 10 , wherein the complexing agent is selected from the group consisting of maleic acid, alendronic acid, itaconic acid, citraconic acid, mesaconic acid, and anhydrides and hemiesters thereof.

12. The aqueous composition according to claim 1 , wherein the aqueous composition contains at least one emulsifier selected from the group consisting of anionic emulsifiers.

13. The aqueous composition according to claim 1 , wherein the aqueous composition contains a mixture of at least two different anionic polyelectrolytes.

14. The aqueous composition according to claim 13 , wherein the at least two different anionic polyelectrolytes are selected from the group consisting of pectins and gellan gum.

15. The aqueous composition according to claim 1 , wherein the aqueous composition contains a mixture of two pectins.

16. The aqueous composition according to claim 1 , wherein the at least one anionic polysaccharide is selected from the group consisting of anionic polysaccharides with at least one of a degree of esterification and a degree of amidation of a carboxy function in the range of 1% to 75% based on a total number of alcohols and carboxy groups.

17. The aqueous composition according to claim 1 , wherein at least one cation selected from the group consisting of Al, Cu, Fe, Mg and Zn are added to the aqueous composition.

18. The aqueous composition according to claim 1 , wherein the aqueous composition contains a crosslinking agent selected from the group consisting of silanes, siloxanes, phenolic resin types, and amines in an amount of 0.01 g/L to 50 g/L.

19. The aqueous composition according to claim 1 , wherein the aqueous composition contains at least one of complex titanium fluorides and zirconium fluorides in an amount of 0.001 g/L to 75 g/L.

Assignees

• Chemetall Gmbh

Inventors

• Wasserfallen Daniel
• Schwamb Michael
• Frenkel Aliaksandr
• Sotke Vera
• Bremser Wolfgang
• Droll Martin
• Seewald Oliver
• Eilinghoff Ron
• Gerold Stephanie
• Niesen Evgenija
• Schachtsiek Lars
• Traut Manuel

Classifications

• C09D5/088

  Autophoretic paints · CPC title

• B05D1/18 Primary

  performed by dipping · CPC title

• B05D7/14 Primary

  to metal, e.g. car bodies (involving a chemical reaction between the metal and the coating C23) · CPC title

• B05D3/0254

  After-treatment · CPC title

• C25D13/04

  with organic material · CPC title