Metal pipes with anticorrosive polyolefin covering layer

Abstract

The present invention provides a metal pipe coated on at least a section of the metal pipe with a polyolefin coating system, wherein the system consists of the following layers: (a) optionally, a corrosion protective layer of a chromate, phosphate or other salt; (b) a polyolefin based adhesive, preferably in a thickness of 0.3-5 mm; (c) a PE or PP coating layer, preferably in a thickness of 1-10 mm; (d) optionally, an adhesion promoting layer between the polyolefin based adhesive and a PE or PP layer; wherein the polyolefin based adhesive contains an organic phase consisting of substantially saturated hydrocarbons, and wherein the adhesive contains amorphous polypropylene, ethylene-propylene copolymers or poly(iso)butylene (co)polymers, said adhesive being flowable when a pressure of 10 kgf/cm2 is applied, wherein the PE or PP coating is a continuous layer over the coated section, and wherein said polyolefin based adhesive adheres to both the metal pipe and to said PE or PP coating.

Dependencies are inferred from the claim text.