| 摘要 |
986,342. Flexible hoses. BTR INDUSTRIES Ltd. March 14, 1962 [April 17, 1961], No. 13762/61. Heading F2P. [Also in Division B5] A hose has an inner, fluid-impervious lining, an outer or outermost layer comprising a thermosetting mixture of polyvinyl chloride, or a copolymer thereof with other vinyl material, with an elastomeric material, e.g. polychloroprene, and an intermediate layer of unimpregnated mineral fibres. The proportions of ingredients used in the outer layer are preferably P.V.C.: polychloroprene = 2 : 1, but may be 2À5-10 : 10 or 1-100 : 10. The layer may include a flame resisting or retarding plasticizer such as tri-xylenyl phosphate, chlorinated diphenyl, or a chlorinated wax, and may also include a nitrile rubber, a filler such as magnesia, and minor quantities of vulcanizing agents for the polychloroprene, polythene, and sodium laurate. The P.V.C. may be copolymerized with vinylidene chloride or vinyl acetate. The layer may be extruded on to or wrapped around, the hose. In an example the hose comprises an inner tube of nitrile rubber or polychloroprene, a layer of cotton or rayon braid or scrim, a layer of nitrile rubber or polychloroprene, a reinforcing braid of wire, or several such layers, a layer of glass fibre mat or bath, which may be between but is preferably outside the braided wire layers and is preferably applied as a strip wrapped helically or longitudinally, and the outer layer as above. The glass fibre layer may be replaced by one of plain or aluminiumized asbestos fibres or a matt or fabric of silica fibres, and the wire braid by braided material of natural or synthetic fibres or by such fibres wrapped with plain or rubberized fabric. Specification 904,638 is referred to. |
