Protective pipe jacket with a diffusion barrier

The invention relates to a protective jacket tube with a diffusion barrier and a core tube made of a plastic and an extruded protective jacket. The invention provides a protective jacket pipe with a good diffusion resistance, which can be produced particularly cost-effectively and in which a high variability with respect to the layer structure and the adhesion to the core tube or the protective jacket, or to other layers surrounding the core tube is ensured , This is achieved by the fact that the diffusion barrier between the core tube and the protective sheath is formed as a multilayer composite film with at least one metal foil layer and / or at least one plastic film with diffusion-inhibiting properties between different plastic layers, for example, polyethylene, polypropylene, polypropylene copolymer, polyamide or other suitable Thermoplastic plastics can exist.