Compositions and methods for depositing amorphous metal-phosphate coatings on metal surfaces

Claim 1

A PROCESS FOR DEPOSITING AN AMORPHOUS METAL - PHOSPHATE COATING ON THE SURFACES OF METALS TO PREVEWNT CORROSION THEREOF WHICH COMPRISES SUBJECTING A METALLIC SURFACE COMPOSED OF AT LEAST ONE OF THE METALS OF THE GROUP CONSISING OF IRON, COPPER, ZINC, SILVER, AND MAGNESIUM TO THE ACTION OF AN AQUEOUS SOLUTION HAVING A PH VALUE BETWEEN ABOUT 3 AND 8, AND CONTAINING IN SOLUTION AT LEAST 100 P. P. M. BY WEIGHT OF A METAL ION OF AT LEAST ONE ELEMENT SELECTED FROM THE GROUP CONSISTING OF CALCIUM, ZINC, COBALT, MAGNESIUM, CADMIUM, IRON, ALUMINUM, BARIUM, STRONTIUM, MANGANESE, CHROMIUM, AND NICKEL, AT LEAST 200 P. P. M. BY WEIGHT OF A WATER-SOLUBLE ALKALI-METAL PHOSPHATE GLASS AND AT LEAST 10 P. P. M. OF AN OXIDIZING AGENT SELECTED FROM THE GROUP CONSISTING OF WATER-SOLUBLE INORGANIC NITRATES, NITRITES, SULFITES, PERMANGANATES, CHROMATES, FERRICYANIDES, DICHROMATES, AND PERBORATES, AND MAINTAINING THE RATIO OF THE PHOSPHATE GLASS CONCENTRATION IN SAID SOLUTION TO THE CONCENTRATION OF THE METAL ION THEREIN BETWEEN THE VALUES OF ABOUT 0.05:1 AND ABOUT 12:1.