| 摘要 |
<p>A light guide with a transparent core of circular or rectangular cross-section with a refractive index up to 10% higher than that of the sheath, in which the core consists of crosslinked polydiorganosiloxane and the sheath consists of a macromolecular substance with long chains of silicon-oxygen groups and/or fluoroalkyl groups. Independent claims are also included for: (a) phase or delay time couplers for light, with a silicone light guide as above mechanically elongated by a definite amount; (b) a method for the production of light guides by passing the monomer mixture for the core material vertically through a die under controlled pressure, curing the mixture in a first coaxial heating section, passing under controlled pressure through a second die into which the monomer mixture for the optically active sheath is introduced coaxially, passing through a second heating section to crosslink the core-sheath structure, and winding on a spool or otherwise processing (e.g. by extrusion or thermoplastic protective coating); (c) a method of production in which the monomer mixtures for core and sheath materials are passed through the inner and outer spaces of a coaxial double die under controlled pressure and then cured in a coaxial heating section; (d) another method of production in which sheath tubing with an inner layer of fluoro-polymer and outer layers of solid-elastic thermoplastics is produced by extrusion and the tubing is then connected to a pressure vessel containing uncrosslinked core monomer mixture which is forced into the tubing and crosslinked, optionally with the aid of a source of heat moving along the tube; and (e) another production method in which tubing made of thermoplastics with polar groups, e.g. polyester, polycarbonate or polyamide, is produced by extrusion, pressure-coated on the inside with a solution of fluoroalkyl-silane which is dried to form a layer of fluoroalkylsiloxane, then filled with a core monomer mixture which is finally cured.</p> |
