| 摘要 |
1466224 Coated optical glass fibres SUMITOMO ELECTRIC INDUSTRIES Ltd 20 March 1975 [20 March 1974 28 Feb 1975] 11783/75 Heading B2E [Also in Division G2] An optical transmission fibre comprises optical glass fibre having on its surface (a) one or more layers formed by coating and baking a liquid resin composition, or solution or dispersion prepared by dissolving or dispersing in a solvent a liquid or solid resin composition and (b) an outer coating of a thermoplastic resin composition formed on the or the outermost layer by melt-extrusion. The resin composition for the lower layer preferably contains polar or functional groups which may react with the surface of the glass. Suitable resins are polyesters, polyamides, polyacetals, polyvinylacetal, polysulphones, polyurethanes, polyethers, polyester imides, polyamideimides, polyamides, polyacrylates, polyvinyl acetate, ethylene-vinyl acetate copolymers, ethylene-acrylic acid copolymers, epoxy resins, epoxy resin derivatives, phenolic resins, resorcinol resins unsaturated polyester resins, urea resins, furan resins, silicone resins, alkyd resins, melamine resins and diallylphthalate resins. Preferably the coating is carried out immediately after the glass fibre has been drawn and before it has come into contact with any other solid object. The refractive index of the coated and baked resin composition and of the thermoplastic resin composition are preferably equal to or greater than the refractive index of the outer portion of the optical glass fibre. Many suitable thermoplastics resins for the melt-extrusion layer are specified. |
