| 摘要 |
A flexible heating element comprises an electrically conducting organopolysiloxane elastomer coated on a non-woven non knitted substrate. The elastomer may be formed by heating a composition comprising 100 parts by weight of an organopolysiloxane gum having therein a small proportion of unsaturated groups, e.g. vinyl or allyl groups, attached to silicon atoms, 25 to 100 parts by weight of carbon black, 0 to 50 parts by weight of one or more other fillers, 0 to 10 parts by weight of a structure control agent and 0.25 to 10 parts by weight of an organic peroxide curing agent, e.g. dicumyl peroxide. The composition may comprise 100 parts by weight of a hydroxy-ended organopolysiloxane gum, 25 to 100 parts by weight of carbon black, 0 to 50 parts by weight of one or more other fillers and 0.5 to 25 parts by weight of an organo triacyloxysilane; or 100 parts of an organopolysiloxane gum having at least two unsaturated groups per molecule, 0.1 to 100 parts by weight of an organosilicon compound having at least two hydrogen atoms directly bonded to a silicon atom per molecule, 25 to 100 parts by weight of carbon black, 0 to 50 parts by weight of one or more other fillers, 0 to 10 parts by weight of a structure control agent and up to 0.2 parts by weight (as platinum) of platinum metal or a platinum-containing catalyst. The composition may be applied by dipping, knife-coating, calendering or spraying. The substrate may be a felted material e.g. asbestos, cellulose-based, polyethylene terephthalate or a polypropylene paper, or a film material e.g. polyethylene terephthalate or polypropylene film. The elastomer coating may be form 0.0005 to 0.01 inch thick. The rearward side of the substrate may be coated with the electrically conducting elastomer or with other material e.g. a water-repellent organopolysiloxane. The element may be provided with electrodes of metal wire, gauze or foil, which may be stapled or stitched to the element, or of metal film or foil which has been deposited on the substrate either electrolytically or by painting. The element may be incorporated in a wall or ceiling heating panel or heating jackets for vessels. |
