Method for coating metal surfaces of substrates and objects coated according to said method

Patent metadata

Field	Value
Publication number	US-10280513-B2
Application number	US-201414903677-A
Country	US
Kind code	B2
Filing date	Jul 16, 2014
Priority date	Jul 18, 2013
Publication date	May 7, 2019
Grant date	May 7, 2019

Abstract

The invention relates to a method for coating surfaces, to a corresponding coating, and to the use of the objects coated according to said method. According to the invention, the method has or consists of the following steps: I. providing a substrate with a cleaned surface, II. contacting and coating the surfaces with an aqueous composition in the form of a dispersion and/or suspension, VI. if necessary rinsing the organic coating, and VII. drying and/or baking the organic coating or VIII. if necessary drying the organic coating and carrying out a coating process using a similar or additional coating composition prior to a drying and/or baking process, wherein between step I and step II, the coating process is carried out using an aqueous composition in the form of a dispersion and/or suspension on the basis of a colloidal silicate sol, which incorporates multivalent metal cations, or a silane- or silicate-modified polymer and if necessary a rinsing process is carried out.

First claim

The invention claimed is:

1. A method for coating metallic surfaces of substrates, comprising the steps of:
I. supplying a substrate having a cleaned metallic surface,
II. coating the cleaned metallic surface with an aqueous composition in the form of a dispersion, suspension or a combination thereof of film-forming polymers consisting of a mixture of at least one stabilized polymer dispersion with a solids content of 30 to 80 wt % with a gelling agent in an amount of 0.001 to 20.0 wt %, based on the total mass of the resulting mixture as well as with cations, forming a coating based on an ionogenic gel,
III. optionally rinsing the coating, drying the coating, baking the coating or a combination thereof, and
IV. optionally forming another coating having a similar or additional coating composition before drying, baking, or a combination thereof,

wherein
between step I and step II, a coating is applied with an aqueous composition in the form of a dispersion, suspension, or a combination thereof based on a colloidal silicatic sol incorporating polyvalent metal cations and optionally a rinsing operation, wherein the polyvalent metal cations, when the aqueous composition includes a demineralized water, are added before the following other constituents: 0.725 g/L to 1.45 g/L of zinc nitrate and 0.22 g/L to 0.55 g/L of hexafluorozirconic acid and 0.66 g/L to 1.1 g/L of manganese nitrate adjusted to about pH 4.5 with sodium carbonate and 25 g/L of amorphous silica.

2. The method according to claim 1 , characterized in that the gelling agent comprises:
a) at least one polysaccharide based on glycogens, amyloses, amylopectins, calloses, agar, algins, alginates, pectins, carrageenan, celluloses, chitins, chitosans, curdlans, dextrans, fructans, collagens, gellan gum, gum arabic, starches, xanthans, gum tragacanth, karayans, tara gum or glucomannans;
b) at least one anionic polyelectrolyte of natural origin, based on polyamino acids, collagens, polypeptides, or lignins;
c) at least one synthetic anionic polyelectrolyte, based on polyamino acids, polyacrylic acids, polyacrylic acid copolymers, acrylamide copolymers, lignins, polyvinyl sulfonic acid, polycarboxylic acids, polyphosphoric acids or polystyrenes or combinations of a), b) or c).

3. The method according to claim 1 , characterized in that the gelling agent comprises at least one polysaccharide, based on pectins, gellan gum or a combination thereof.

4. The method according to claim 1 , characterized in that the aqueous composition, the coating or a combination thereof contain(s) a mixture of at least two different gelling agents.

5. The method according to claim 4 , characterized in that the aqueous composition, the coating or a combination thereof contain(s) a mixture of two pectins.

6. The method according to claim 1 , characterized in that the aqueous composition, the coating or a combination thereof contains at least one anionic polysaccharide, selected from those with a degree of esterification of the carboxyl function in the range of 5 to 75%, based on the total number of alcohol groups and carboxyl groups.

7. The method according to claim 1 , characterized in that the aqueous composition, the coating or a combination thereof contains at least one anionic polysaccharide, at least one anionic polyelectrolyte or a combination thereof, selected from those with a molecular weight in the range of 500 to 1,000,000 g/mol.

8. The method according to claim 1 , characterized in that the aqueous composition, the coating or a combination thereof contains at least one anionic polysaccharide, at least one anionic polyelectrolyte or a combination thereof, selected from those with a degree of amidation of the carboxyl functions in the range of 1 to 50% or a degree of epoxidation of the carboxyl functions of up to 80%.

9. The method according to claim 1 , characterized in that the anionic polyelectrolytes are or have been modified with adhesion-promoting adhesive groups, selected from the group consisting of chemical groups of multifunctional epoxies, isocyanates, primary amines, secondary amines, tertiary amines, quaternary amines, amides, imides, imidazoles, formamides, Michael reaction products, carbodiimides, carbenes, cyclic carbenes, cyclocarbonates, multifunctional carboxylic acids, amino acids, nucleic acids, methacrylamides, polyacrylic acids, polyacrylic acid derivatives, polyvinyl alcohols, polyphenols, polyols having at least one alkyl and/or aryl radical, caprolactam, phosphoric acids, phosphoric acid esters, epoxy esters, sulfonic acids, sulfonic acid esters, vinyl sulfonic acids, vinyl phosphonic acids, catechol, silanes as well as the silanols, siloxanes or combination thereof produced from the former, triazines, thiazoles, thiazines, dithiazines, acetals, hemiacetals, quinones, saturated fatty acids, unsaturated fatty acids, alkyds, esters, polyesters, ethers, glycols, cyclic ethers, crown ethers, anhydrides as well as the acetylacetones and β-diketo groups, carbonyl groups and hydroxyl groups.

10. The method according to claim 1 , characterized in that the aqueous composition, the coating or a combination thereof contains at least one complexing agent for metal cations or a polymer modified for complexing metal cations.

11. The method according to claim 10 , characterized in that the aqueous composition, the coating or a combination thereof contains at least one complexing agent selected from those based on maleic acid, alendronic acid, itaconic acid, citraconic acid or mesaconic acid or the anhydrides or hemiesters of these carboxylic acids.

12. The method according to claim 1 , characterized in that the aqueous composition, the coating or a combination thereof contains at least one type of cations, selected from those based on cationic salts, 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 Ag, Al, B, Ba, Ca, Co, Cu, Fe, In, Mg, Mn, Mo, Ni, Pb, Sn, Ta, Ti, V, W, Zn, Zr or combinations thereof.

13. The method according to claim 12 , characterized in that Ag, Al, Cu, Fe, Mg, Zn or combinations thereof are selected as cations that have been dissolved out of the metallic surface, added to the aqueous composition for incorporation into the silicate-modified polymer or a combination thereof.

14. The method according to claim 1 , characterized in that the aqueous composition contains a crosslinking agent selected from the group consisting of: silanes, siloxanes, phenolic resin types or amines in an amount of 0.01 g/L to 50 g/L.

15. The method according to claim 1 , characterized in that the aqueous composition contains complex titanium, zirconium fluorides or a combination thereof in an amount of 0.01 g/L to 50 g/L.

16. The method according to claim 15 , characterized in that the aqueous composition contains complex titanium, zirconium fluorides or a combination thereof in an amount of 0.01 g/L to 30 g/L.

17. The method according to claim 1 , characterized in that the aqueous composition contains an amount of at least one defoaming agent.

18. The method according to claim 1 , characterized in that the aqueous composition contains at least one additive selected from the group, consisting of: pigments, biocides, dispersion aids, film-forming aids, acidic additives for adjusting the pH, basic additives for adjusting the pH, thickeners, flow control agents and combinations thereof.

19. The method according to claim 1 , characterized in that the metallic sur

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
• Klöpzig Philipp

Classifications

• C09D105/02

  Dextran; Derivatives thereof · CPC title

• C09D189/00

  Coating compositions based on proteins; Coating compositions based on derivatives thereof (foodstuff preparations A23J3/00) · CPC title

• C09D197/005

  Lignin · CPC title

• C09D5/02

  Emulsion paints {including aerosols} · CPC title

• C23C18/125 Primary

  Process of deposition of the inorganic material · CPC title