Patent EP-2023688-B1 (EP)
Inventor: KOCH HANS-GUENTHER
IPC: H05B3/36
Filed: 2007-08-03
Granted: 2010-03-17
Abstract: The panel form electrically conductive film useful as floor heater under tiles or wooden floorings, comprises a thermoplastic matrix with reinforcing fibers (3-45 wt.%) and electrical contacts, and additives (7 wt.%). The reinforcing fibers consist of electrically conductive reinforcing fibers with a fiber length of 3-6 mm and a thickness of 5-8 mu m. The electrically conductive reinforcing fibers are present in the foil isotropically in x-y direction in the thermoplastic matrix. The ratio of the electrical conductivity from the x to the y-direction is 1-3 to 1.2-2.2. The panel form electrically conductive film useful as floor heater under tiles or wooden floorings, comprises a thermoplastic matrix with reinforcing fibers (3-45 wt.%) and electrical contacts, and additives (7 wt.%). The reinforcing fibers consist of electrically conductive reinforcing fibers with a fiber length of 3-6 mm and a thickness of 5-8 mu m. The electrically conductive reinforcing fibers are present in the foil isotropically in x-y direction in the thermoplastic matrix. The ratio of the electrical conductivity from the x to the y-direction is 1-3 to 1.2-2.2. The conductive reinforcing fibers are carbon fibers, metal fibers and/or conductive endowed thermoplastic fibers. The portion of the electrically conductive reinforcing fibers is 0.5-20 wt.%. Additional reinforcing fibers are present beside the electrically conductive fibers and have a fiber length of 6-12 mm. The additives are binders, tribologically effective additives, and additives for the stability, impact strength, temperature stability, heat conductivity, abrasion stability and/or electrical conductivity, and are used in the form of fibers, fibrils, fibrids, pulp, powders, nano-particles, nano-fibers and/or mixtures. The electrical conductivity of the foil is adjusted by the variation of the density of the foil with a predetermined part by weight of the conductive reinforcing fiber or by the variation of the part by weight of the foil with a predetermined density of the conductive reinforcing fiber. The foil has holes with same or different geometry, or perforations, which form a pattern. The electrical conductivity of the foil is adjusted by the perforations and/or holes with the predetermined thickness and/or part by weight of the conductive reinforcing fiber. The conductive film has a density of 0.25-6 g/cm 3>, and a thickness of 30-350 mu m. The electrical contact is an integral component of the conductive foil, and is formed by a copper contact path in a form of a strip in two boundary regions of the foil. The conductive film is present in panel form and two plates are connected with one another by contact points in an electrically-conducting manner. The connection takes place by crimping, serrated lock washers, soldering, welding, rivets, plug connectors, pushbuttons and/or adhesive tapes. The film is three-dimensionally deformed. A layer made of electrically isolating material is applied on the both surface of the film. An independent claim is included for a method for the production of a conductive foil.