Two-layered or three-layered polymer tubing for use as a pressurized fluid
conduit in automobiles can be either walled or have walls continuously or
partially corrugated. The tubing has an outer layer of a hard polymer
molding material and an inner layer of a soft rubber-like polymer or a
polymer mixture. The inner layer can be provided on the innerside with a
layer of a thermoplastic adhesion-modified elastomer composition. The a
materials are selected for the layers to provide a so-called
"hard-soft-combination". The rubber-like polymer composition has a
hardness in the range of 30 Shore A to 60 Shore D, especially of about 30
Shore A to 90 Shore A, the compositions being selected so that they are
processable by coextrusion or the so-called conex method and adhere
directly to each other non-positively or positively fitted, i. e. without
additional bonding agent, without delaminating.