METHOD OF MAKING ANTICORROSION PIGMENT BASED ON ALUMINIUM AND MOLYBDENUM PHOSPHATES Russian patent published in 1998 - IPC

FIELD: chemical industry, more particularly primers, compositions, paint materials for protection various metals and alloys from corrosion. SUBSTANCE: pigment with high anticorrosion properties is prepared by simplified flowsheet: in the same apparatus operation is first carried out to dissolve suspension of aluminium hydroxide and molybdenum compound having concentration of 180-200 g/cubic dm in terms of dry Al(OH)₃ and molybdenum compound in Al₂O₃:MoO₃ weight ratio of 1.0: 0.1- 0.5 with orthophoric acid, and operation is then carried out to procipate aluminium and molybdenum phosphates by feeding into apparatus lime milk or highly dispersed calcium carbonate suspension with concentration of 100- 150 g/cubic dm in terms of CaO and at room temperature till pH is attained within 5.5-8.0 followed by stirring, filtration and drying of the final product. With respect to anticorrosion properties, coating made of aluminium and molybdenum phosphates-based primer is more advantageous than that of aluminium phosphate-based primer. EFFECT: more efficient preparation method. 1 tbl