Fire resistant cable with ceramifiable layer

摘要

Existing ceramifiable compositions used in fire resistant cables form non-uniform ceramic layers which crack or swell when exposed to heat. The present invention seeks to overcome this problem by providing a fire resistant cable comprising: at least one conducting element; at least one layer, surrounding said conducting element, made of a ceramifiable composition comprising: a polymeric material comprising an ethylene/vinyl acetate copolymer as main polymer; at least 25 wt% of silica; a fluxing agent selected from alkaline metal oxides or precursors thereof; a stabilizing agent comprising at least one of MgO, CaO, PbO, B203, or a precursor thereof; from 0.1 wt% to 5 wt% of a hydroxide selected from magnesium hydroxide, aluminium hydroxide and mixtures thereof; the above percentages being expressed with respect to the weight of the ceramifiable composition. Upon exposure to elevated temperatures such as those encountered in case of fire, the ceramifiable composition is transformed into a ceramic material capable of protecting the conducting element from fire and mechanical stresses. The fire resistant cable of the present invention can continue operating under fire conditions for a certain period of time.