| 摘要 |
1,261,280. Optical fibre structures. NIPPON SHEET GLASS CO. Ltd. 21 Oct., 1969 [23 Oct., 1968], No. 51637/69. Heading C1M. A structure of glass optical fibres is produced by cementing together into a bundle in parallel relationship a plurality of glass optical filaments, each comprising a core of glass sheathed in glass of a lower refractive index than that of the core glass or multifilaments (a multifilament comprises, e.g. 4-20 filaments fused together) with a binder which evaporates or sublimes below the glass fusion temperature but which is solid at the temperature of any cutting or shaping operation, heating the bundle to cause sublimation or vaporization of the binder and further heating to fuse the filaments or multifilaments together. The binder may be poured into the interstices of a parallel bundle of fibres and then solidified, or fibres may be coated with binder while winding, e.g. onto a drum. The binder may be water; a C 8-18 monocarboxylic aliphatic acid (e.g. caprylic, capric, lauric, myristic, palmitic or stearic acid); aliphatic C 4-6 dicarboxylic acid (e.g. succinic. or adipic acid); a halogen-substituted C 2 carboxylic acid (e.g. chloroacetic acid); aromatic C 6-10 hydrocarbons (e.g. benzene, naphthalene); halogenated benzene (e.g. p-dichloro-benzene); hydroxy-substituted benzene (e.g. phenol or p-cresol); dlcamphene; 1-menthol or cetyl alcohol. The binders may be used in a solvent, e.g. methanol, ethanol, acetone or diethyl ether. When water is used it may be solidified by cooling, and the cutting or shaping carried out on the icecemented bundle. The vaporization or sublimation.may be carried out at 20-400‹ C. and under. a reduced pressure of 0À1-5 mm. Hg, and the heat fusion at 450-700‹ C. and/or under pressure. from formers, e.g. of copper, graphite, boron nitride: or silicon nitride. The invention is particularly useful for cutting face plates for TV tubes of large diameter.
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