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

A method for coating metallic surfaces of substrates comprising the steps of:

• preparing a substrate with a cleaned metallic surface,
• contacting and coating metallic surfaces with an aqueous composition in the form of a dispersion or suspension,
• optionally rinsing the organic coating;
• and
• drying or baking the organic coating or
• optionally drying the organic coating and coating with a similar or additional coating composition before drying or baking,
• wherein the aqueous composition is in the form of dispersion and suspension,
• wherein the aqueous composition comprises an anionic polyelectrolyte in an amount of 0.01 to 5.0 wt %, based on the total mass of the aqueous composition;
• and wherein the anionic polyelectolyte is added to a dispersion of film-forming polymers or a suspension of film-forming inorganic particles with a solids content of 2 to 40 wt % and an average particle size of 10 to 1000 nm to form the aqueous composition, wherein the aqueous composition has a pH value in the range of 4 to 11 and forms a coating based on an ionogenic gel which binds cations dissolved out of the metallic surface, wherein the cations originating from a pretreatment stage or from the contacting.

A method for coating metallic surfaces of substrates comprising the steps of:

• preparing a substrate with a cleaned metallic surface;
• contacting and coating metallic surfaces with an aqueous composition, wherein the aqueous composition is a suspension;
• and
• drying or baking the organic coating;
• wherein the suspension comprises an anionic polyelectrolyte in an amount of 0.01 to 5.0 wt % based on the total mass of the suspension and film-forming inorganic particles;
• wherein the suspension has a solids content of from 2 to 40 wt % and wherein the film-forming organic particles have an average particle size of from 10 to 1000 nm;
• wherein the aqueous composition has a pH value in the range of 4 to 11;
• and
• wherein the aqueous composition forms a coating based on an ionogenic gel which binds cations dissolved out of the metallic surface, wherein the cations originating from a pretreatment stage or from the contacting.

A method for coating metallic surfaces of substrates comprising the steps of:

• preparing a substrate with a cleaned metallic surface;
• contacting and coating metallic surfaces with an aqueous composition comprising organic solids, wherein the aqueous composition is a dispersion of film-forming polymers;
• and
• drying or baking the organic coating;
• wherein the dispersion comprises an anionic polyelectrolyte in an amount of 0.01 to 5.0 wt % based on the total mass of the dispersion;
• wherein the aqueous composition has a solids content of 2 to 40 wt % and the solids therein have an average particle size of 10 to 1000 nm,
• wherein the aqueous composition has a pH value in the range of 4 to 11;
• and
• wherein the aqueous composition forms a coating based on an ionogenic gel which binds cations dissolved out of the metallic surface, wherein the cations originating from a pretreatment stage or from the contacting.