SELF-PRIMING CHROMATE FREE CORROSION RESISTANT COATING COMPOSITION AND METHOD

摘要

The invention discloses a self-priming rapid curing chromate free corrosion resistant coating composition based on a random polyvinvl terpolymer and an alkyd resin with hydroxyl number ranging between 80-200 in association with a mineral acid catalyst, one or more organic solvents and a drying agent where in the said vinyl terpolymer is predominantly a polyvinyl formal with polyvinyl alcohol and polyvinyl acetate as the other two co-polymers, the said terpolymer cross linking through its hydroxyl groups with the alkyd resin in the composition during curing. The composition can be applied as a clear coa t or as a pigmented composition with addition of pigments on ferrous and non- ferrous metallic substrate and is particularly suitable for continuous coil coating lines. The invention also concerns a method of coating a ferrous and non-ferrous metallic substrate by applying the said coating composition on i ts surface and coated articles so produced.