| 摘要 |
Antistatic and fire-resistant conveyer or transmission belting is made from fabric comprising yarns containing combustible cotton, rayon, nylon, or polyethylene terephthalate fibres or filaments associated in the weft and/or the warp with filaments of a flexible thermoplastic fire-resistant polymer or copolymer of vinyl chloride or vinylidene chloride, one or both sets of fibres or filaments being rendered antistatic by the incorporation of an antistatic agent, the noncombustible fibres or filaments being at least 15% by weight of the total, and the fabric being embedded in a resilient fire-resistant thermoplastic composition. One or more plies of such fabric is or are embedded in similar fire-resistant thermoplastic material, and subjected to heat and pressure such that the fire-resistant yarns or components fuse and impregnate the remaining yarns or components. The fabric may comprise yarns of mixed fire-resistant and other filaments or fibres, or yarns or threads of the two kinds associated by doubling, or such yarns woven together in the warp and/or weft. The fire-resistant components are rendered flexible by the incorporation of a solid or liquid plasticizer. The antistatic material may be incorporated in both the fire-resistant components of the fabric and in the enveloping fire-resistant material, and may comprise acetylene black or other forms of conductive carbon, esters of polyethylene glycols having from 2-10(C2H4O) groups combined with one or more molecules of saturated or unsaturated fatty acids of 4-18 carbon atoms, for example polyethylene glycol mono-oleate or triethylene glycol dicaprylate, or tertiary amines or quaternary salts thereof containing at least one polyoxyalkylene group and at least one phenyl or substituted phenyl group which renders the compound oil-soluble, or for example the compound having the average composition (C17H33) N[(C2H4O)4,5H]2 or its quaternary salt with dimethyl sulphate. A suitable fire-resistant antistatic composition comprises polyvinyl chloride, tritolyl phosphate, dioctylphthalate, stabilizer, conductive carbon black, antimony trioxide, zinc borate, boric acid, and natural rubber, the rubber being stated to give a product which can be milled and extruded without unduly affecting its antistatic properties. The non fire-resistant components of the fabric may also be impregnated with solutions or dispersions of the above antistatic agents, or, in the case of plastic components, may have conductive carbon black incorporated in them during formation. Specifications 741,738, 787,177 and 820,541 are referred to. |
