Corrosion-inhibiting pigments, their production and use

A process for manufacturing a pigment, for paints and varnishes compatible with galvanized steel substrates, non-galvanized steel substrates, as well as aluminum substrates, said process consisting essentially of:

• forming a slurry consisting essentially of a first component selected from the group consisting of metallic oxides, metallic phosphates, metallic molybdates and mixtures thereof, wherein the metal is at least one member selected from the group consisting of zinc, aluminum, iron, barium, strontium, calcium, magnesium and titanium;
• wet conditioning said first component in said slurry;
• adding to said wet conditioned first component in said slurry soluble chromate in an amount equivalent to 0.03 to 0.6 weight percent sodium dichromate, based on the total weight of the pigment, said soluble chromate being in the form of a compound selected from the group consisting of sodium dichromate, potassium dichromate, ammonium dichromate, sodium chromate, potassium chromate, ammonium chromate, chromic acid and mixtures thereof;
• homogenizing the thus formed mixture of the first component and soluble chromate;
• and
• drying the homogenized mixture.

A process for manufacturing a pigment for paints and varnishes compatible with galvanized steel substrates, non-galvanized steel substrates, as well as aluminum substrates, said process consisting essentially of:

• forming a slurry consisting essentially of a first component selected from the group consisting of metallic oxides, metallic phosphates, metallic molybdates and mixtures thereof, wherein the metal is at least one member selected from the group consisting of zinc, aluminum, iron barium strontium, calcium;
• magnesium and titanium;
• wet conditioning said first component in said slurry;
• drying said slurry after said wet conditioning to result in dried and conditioned first component;
• adding soluble chromate to said dried and conditioned first component in an amount equivalent to 0.03-0.6 weight percent sodium dichromate, based on the total weight of the pigment, said soluble chromate being in the form of a compound selected from the group consisting of sodium dichromate, potassium dichromate, ammonium dichromate, sodium chromate, potassium chromate, ammonium chromate, chromic acid and mixtures thereof;
• and
• drying pulverizing the mixture of said first component and the soluble chromate to uniformly distribute said soluble chromate throughout said mixture.

A process for manufacturing a pigment for paints and varnishes compatible with galvanized steel, non-galvanized steel, as well as aluminum substrates, said process consisting essentially of:

• selecting a dry first component from the group consisting of metallic oxides, metallic phosphates, metallic molybdates and mixtures thereof, wherein the metal is at least one member selected from the group consisting of zinc, aluminum, iron, barium, strontium, calcium, magnesium and titanium;
• adding soluble chromate to said dry first component in an amount equivalent to 0.03-0.6 weight percent sodium dichromate, based on the total weight of the pigment, said soluble chromate being in the form of a compound selected from the group consisting of sodium dichromate, potassium dichromate, ammonium dichromate, sodium chromate, potassium chromate, ammonium chromate, chromic acid and mixtures thereof;
• and
• drying pulverizing the mixture of said first compound and said soluble chromate to uniformly distribute said soluble chromate throughout said mixture.