Flexible tube and manufacture thereof

PURPOSE:To obtain the captioned tube useful for the wire leading tube of medical endoscope or the like by a method wherein the inner surface of polytetrafluorethylene porous tube is covered with fluorocarbon polymer having a melting point lower than that of the former while the outer surface thereof is covered with rubber elastic body. CONSTITUTION:Aqueous dispersion or organic solvent medium dispersion of fluorcarbon copolymer having lower melting point than that of the porous tube is coated on the inner surface of the polytetrafluoroethylene porous tube and dried, thereafter, is heated to bond thereto, subsequently, the outer surface of this tube is treated with anhydrous ammonia or Na complex salt of naphthalene to provide adhesibility to the nonadhesive surface thereof, thereafter, solution of rubber blend containing 10-75wt% of fine particulate fluorocarbon copolymer is coated thereon and dried, then it is heated to form the rubber elastic body with the coated film of crosslinked rubber having slidability and air-tightness, thus, the flexible tube is manufactured.