Cable with metallic tight tube comprising at least one optical conductor and an hydrogene absorbing substance

摘要

The communications cable structure has a sealed metal tube containing at least one optic fiber and a material to absorb hydrogen. The inner surface of the tube (20) is coated at least partially with a layer (22) which is a catalyst for the absorbent action of the hydrogen by the absorbent material (30). The surface layer is itself coated at least partially by a hydrogen absorbent material (30). The catalyst layer (22) is made of a tough material, with grooves, and contains at least one polymer. The outer surface of the tube is coated at least partially with an anticorrosive material, essentially the same as the inner catalyst layer (22). The polymer in the catalyst material has double links which open in the presence of the catalyst to secure the hydrogen within their openings. The catalyst is a group VIII element in the fourth to six periods from the periodic table, of nickel or chrome. The sealed tube is of soft steel. The hydrogen-absorbent material fills the tube (30), and can be a single layer on the catalyst layer (22), containing an adhesive. An Independent claim is included for a manufacturing process where a metal sheet is coated with a catalyst layer, and then formed into a tube. The optic fiber is fed into the tube together with the filling material. The longitudinal edges are welded together and the tube is shrunk after welding. Preferred Features: The catalyst cladding is further coated with a material to absorb hydrogen, before shaping into a tube. The edges are adhesive bonded together, using the hydrogen-absorbent material as the adhesive.