Metallic Pigments for
Paint and Lacquers
l Patent No. U.S. 6,503,304
Eckart has been granted a patent for a flowable and pumpable aqueous semifinished product of gassing stability for the production of paints and lacquers, comprising ten to 67 parts of water; 30 to 70 parts of a pre-stabilized metallic pigment; and three to 35 parts of an anticorrosive pigment. The metallic pigment consists of aluminum, copper, zinc, tin or alloys of aluminum, copper, zinc or tin, and the metallic pigment is pre-stabilized by phosphor-containing organic compounds and bases, by coating with silicates or organically modified silanes, by polymers or by phosphoric acid ester. The anticorrosive pigment is pasted in a bead mill in a suitable aggregate, for a period of five to 30 minutes at 8,000 to 12,000 rpm with the addition of water and a dispersing agent and adding at least one of a defoamer and thixotroping additive. A stabilized aqueous metallic paste, wherein it contains a pre-stabilized metallic pigment and five to 20% of an anticorrosive pigment selected from the group consisting of strontium zinc phosphosilicate, zinc aluminum polyphosphate hydrate, zinc calcium aluminum strontium phosphate silicate hydrate, zinc calcium strontium orthophosphate silicate hydrate, strontium aluminum polyphosphate hydrate, calcium aluminum polyphosphate silicate hydrate, sodium molybdate, calcium molybdate, zinc molybdate, soldium phospho-molybdate, calcium phospho-molybdate and zinc phospho-molybdate.
A method for the production of a metallic paste, wherein 60 to 80 parts of a metallic powder containing a pre-stabilized metallic pigment are added to a suspension of five to 25 parts of an anticorrosive pigment in 18 parts water and are kneaded together with a kneading aggregate, forming a paste.