Plural coating with epoxy primer and alkyd-silicone topcoat

Claim 1

THE METHOD OF PREPARING AN ARTICLE HAVING A DURABLE PROTECTIVE TWO-COAT COATING THEREON, WHICH COMPRISES: PROVIDING A BASE ARTICLE WHICH IS TO BE COATED AND WHICH IS CAPABLE OF WITHSTANDING THE BAKING TEMPERATURES USED TO CONVERT THE HEREINAFTER-DEFINED APPLIED COATINGS TO A PROTECTIVE COATING SYSTEM; APPLYING TO SAID BASE A PRIMING COAT COMPRISING AS THE SOLE FILM-FORMING MATERIAL THEREIN A RESINOUS MOIETY COMPOSED OF AT LEAST ONE POLYMERIC POLYETHER DERIVATIVE OF POLYHYDRIC PHENOL, SAID DERIVATIVE HAVING ALTERNATING AROMATIC AND ALIPHATIC NUCLEI UNITED THROUGH ETHER OXYGEN, HAVING TERMINAL EPOXY GROUPS AND BEING FREE OF FUNCTIONAL GROUPS OTHER THAN EPOXY AND HYDROXYL GROUPS; BAKING SAID BASE AND APPLIED PRIMING COAT SUFFICIENTLY TO CONVERT SAID PRIMING COAT TO A FILM WHICH IS INCOMPLETELY CURED BUT WHICH IS NONTACKY AT ATMOSPHERIC TEMPERATURES; THEN APPLYING ON SAID NON-TACKY PRIMING COAT A PIGMENTED TOP-COAT HAVING A THICKNESS OF AT LEAST 0.5 MIL AND COMPRISING AS THE PRINCIPAL FILM-FORMING MATERIAL THEREIN AT LEAST ONE HOMOGENEOUS RESINOUS ALKYD-SILICONE COPOLYMER CONTAINING POLYCARBOXYLIC ACID WHICH HAS BEEN CHEMICALLY COMBINED THEREWITH WITHOUT CONSUMING ALL OF ITS CARBOXYL GROUPS, THEREBY TO PROVIDE A PRINCIPAL FILM-FORMING MATERIAL HAVING AT LEAST A SMALL AMOUNT OF CARBOXYL GROUPS AVAILABLE FOR REACTION WITH THE FILM-FORMING MATERIAL OF SAID PRIMER; AND THEREAFTER BAKING SAID BASE AND ITS APPLIED PRIMING AND TOP-COATS SUFFICIENTLY TO BRING ABOUT CHEMICAL REACTION OF CARBOXYL GROUPS OF THE TOP-COAT WITH SAID PRIMING COAT AND THEREBY TO CONVERT THE TWO COATS TO A PROTECTIVE COATING SYSTEM.

Claim 2

THE METHOD OF PREPARING AN ARTICLE HAVING A DURABLE PROTECTIVE TWO-COAT COATING THEREON, WHICH COMPRISES: PROVIDING A BASE ARTICLE WHICH IS TO BE COATED AND WHICH IS CAPABLE OF WITHSTANDING THE BAKING TEMPERATURES USED TO CONVERT THE HEREINAFTER-DEFINED APPLIED COATINGS TO A PROTECTIVE COATING SYSTEM; APPLYING TO SAID BASE A PRIMING COAT COMPRISING AS THE SOLE FILM-FORMING MATERIAL THEREIN A RESINOUS MOIETY COMPOSED OF AT LEAST ONE POLYMERIC POLYETHER DERIVATIVE OF POLYHYDRIC PHENOL, SAID DERIVATIVE HAVING ALTERNATING AROMATIC AND ALIPHATIC NUCLEI UNITED THROUGH ETHER OXYGEN, HAVING TERMINAL EPOXY GROUPS AND BEING FREE OF FUNCTIONAL GROUPS OTHER THAN EPOXY AND HYDROXYL GROUPS; BAKING SAID BASE AND APPLIED PRIMING COAT SUFFICIENTLY TO CONVERT SAID PRIMING COAT TO A FILM WHICH IS INCOMPLETELY CURED BUT WHICH IS NONTACKY AT ATMOSPHERIC TEMPERATURES; THEN APPLYING ON SAID NON-TACKY PRIMING COAT A PIGMENTED TOP-COAT HAVING A THICKNESS OF AT LEAST 0.5 MIL AND COMPRISING AS THE PRINCIPAL FILM-FORMING MATERIAL THEREIN AT LEAST ONE HOMOGENEOUS RESINOUS ALKYD-SILICONE COPOLYMER CONTAINING POLYCARBOXYLIC ACID WHICH HAS BEEN CHEMICALLY COMBINED THEREWITH WITHOUT CONSUMING ALL OF ITS CARBOXYL GROUPS, THEREBY TO PROVIDE A PRINCIPAL FILM-FORMING MATERIAL HAVING AT LEAST A SMALL AMOUNT OF CARBOXYL GROUPS AVAILABLE FOR REACTION WITH THE FILM-FORMING MATERIAL OF SAID PRIMER; AND THEREAFTER BAKING SAID BASE AND ITS APPLIED PRIMING AND TOP-COATS SUFFICIENTLY TO BRING ABOUT CHEMICAL REACTION OF CARBOXYL GROUPS OF THE TOP-COAT WITH SAID PRIMING COAT AND THEREBY TO CONVERT THE TWO COATS TO A PROTECTIVE COATING SYSTEM.