Abstract: A process for coating electrically conductive substrates by (1) applying an electrocoat film to an electrically conductive substrate and curing it to give an electrocoat and then (2) applying a layer of a pulverulent coating material to the electrocoat and curing it to give a powder coat or alternatively (1) applying an electrocoat film to an electrically conductive substrate and drying it without fully curing it, (2) applying a layer of a pulverulent coating material to the dried electrocoat film(s) and (3) jointly curing the dried electrocoat film and the layer of the pulverulent coating material to give the electrocoat and the powder coat wherein the pulverulent coating material comprises (A) at least one epoxy resin having a melting point, melting range or glass transition temperature>30° C., (B) at least one carboxyl-containing polyester resin having a melting point, melting range or glass transition temperature>30° C.

Abstract: The invention relates to three-layer metal pipe coating compositions based on a powder primer, on a thermoplastic hard adhesive and on a polyolefin cladding. The powder primer contains epoxidized novolak resins, phenolic crosslinking agents and fillers based on crystalline silicic acid modifications. The invention likewise relates to a process for the exterior coating of metal pipes by a three-layer method, in which the powder primer described is applied to the metal pipe, a thermoplastic hard adhesive is applied to the powder primer, and subsequently a polyolefin cladding is applied.