The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 10, 2003
Filed:
Apr. 06, 2001
Pietro Anelli, Cremona, IT;
Gianfranco Colombo, Sesto San Giovanni, IT;
Pirelli Cavi e Sistemi S.p.A., Milan, IT;
Abstract
The present invention relates to a cable, in particular an optical fiber cable, which is resistant to the radial permeation and to the longitudinal propagation of water. This cable contains a water-soluble polymer material which is a water-swellable and water-soluble material. In particular, this cable is characterized in that, following the ingress of water into this cable, the propagation of water is impeded on account of the combined effect of the swelling of the water-soluble material and the formation of an aqueous solution of said material which has a predetermined viscosity, so as to impede the passage of the residual water. Preferably, the water-soluble material is chosen from polyacrylamide, modified polyvinyl alcohol, vinyl alcohol/vinyl acetate copolymers, polyvinylpyrrolidone, and mixtures thereof, the material preferably being a vinyl alcohol/vinyl acetate copolymer. The material can advantageously be extruded to form tubular elements for containing optical fibers, for example, two-layer tubular elements in which the inner layer is made of water-soluble material and the outer layer is made of a conventional polymer such as PE, PP or PBT.