Abstract: An epoxy based primer composition comprising at least 10% zinc oxide w/w dry solids is described. A coated metal substrate is also described comprising a metal substrate, at least one epoxy based primer layer, the primer layer comprising at least 10% w/w zinc oxide in the dry primer coating, and at least one top-coat adhered to the primer layer. A process of coating a metal substrate is also described.

Abstract: The present invention relates to an epoxy modified polysiloxane composition obtainable by combining the following ingredients:—a polysiloxane of formula (1), wherein each R1 is independently selected from hydroxy, alkyl, aryl or alkoxy radicals having up to six carbon atoms, each R2 is independently selected from hydrogen, alkyl or aryl radicals having up to six carbon atoms and, wherein n is selected so that the molecular weight for the polysiloxane is in the range of from about 400 to 10,000; with formula (1)—an epoxy resin having more than one 1,2-epoxy groups per molecule with an epoxy equivalent weight in the range of from 100 to about 5,000; and—an amino hardener component having active hydrogens able to react with epoxy groups in the epoxy resin to form polymers containing hydroxyl groups, which are able to react with the silanol groups of hydrolyzed polysiloxane to form a polymer network, wherein the epoxy chain polymers and polysiloxane polymers polymerize to form a cured epoxy modified polysiloxane