Process for forming chemical resistant synthetic resin coatings on metal and product thereof

Claim 1

A PROCESS OF FORMING A TOUGH, ADHERENT, CHEMICALLYRESISTANT SURFACE COATING ON METAL COMPRISING THE STEPS OF APPLYING TO THE METAL A LIQUID SURFACE-PREPARATION COAT CONSISTING ESSENTIALLY OF A DISPERSION OF A FILM-FORMING VINYL POLYMER SELECTED FROM A GROUP CONSISTING A POLYVINYL FORMAL, POLYVINYL ACETAL AND POLYVINYL BUTYRAL, SAID SURFACE PREPARATION COAT HARDENING UNDER ATMOSPHERIC CONDITIONS; APPLYING TO THE SURFACE-PREPARATION COAT SO LAID DOWN AT LEAST ONE LIQUID INTERMEDIATE COAT CONSISTING ESSENTIALLY OF A HEAVILY PIGMENTED FILM-FORMING EPOXIDE RESIN, SAID INTERMEDIATE COAT HARDENING UNDER ATMOSPHERIC CONDITIONS; AND, AFTER HARDENING OF THE LAST OF THE PRIOR COATS HAS TAKEN PLACE, APPLYING THERETO A FINISHING COAT CONSISTING ESSENTIALLY OF A FILM-FORMING EPOXIDE RESIN, EACH OF SAID COATS RETAINING ITS IDENTITY TO A LARGE EXTENT WITH LITTLE FUSION BETWEEN SUCCESSIVE COATS.