Coated pipe and process for making same
AssigneeThe Kendall Company
InventorsCarlos M. Samour, Earl G. Jackson, Samuel J. Thomas, Louie E. Davidson
Life of this patent
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Abstract
Steel pipe is provided with an external protective coating by first applying a corrosion protective coating of fused powdered epoxy resin adhered to the pipe, then applying (e.g. as by wrapping a sheet) an outer polyolefin layer directly onto the corrosion protective coating. The outer sheet of polyolefin is provided with a pressure-sensitive adhesive or a hot melt adhesive which adhesive may also be reactive with the epoxy coating (e.g. one having free carboxyl group such as ethylene acrylic acid copolymer). The polyolefin is preferably polyethylene or polypropylene and most preferably polyethylene. Either high or low density polyolefin may be used.
Claims16
A coated article comprising a metallic pipe having a protection layer thereon, said layer comprising a first layer bonded to the pipe of an epoxy coating derived from a bis-phenol A polymer of 2 to 10 mils and an adhesive faced thermoplastic polymer tape wrapping adhesively bonded to said epoxy coating, said protection layer being from 6 to about 50 mils in thickness.
A process for externally protecting metal pipe which comprises providing heated pipe, electrostatically applying fusible Epoxy resin powder derived from a bis-phenol A polymer to the exterior surface of the metal to form a continuous coating of from 2 to 10 mils in thickness and thereafter spirally wrapping an adhesive-faced flexible thermoplastic polymer substrate so that the thickness of the epoxy coating and tape wrapping is from 6 to 50 mils.
Dependencies are inferred from the claim text.