摘要:
The present invention relates to a PTC composition comprising, by weight, the total being 100%: A) 40 to 80% of PVDF; B) 0 to 40% (advantageously 10 to 40%) of an acrylic or styrene polymer; C) 0 to 40% of an epoxy resin; D) 0 to 60% of at least one metal oxide; E) 0 to 25% of a carbonaceous conductive filler D+E being equal to at least 10%. To prepare the composition of the invention, the various constituents are blended in such a way that (A) is in the melt state, then the product obtained is extruded, moulded or injection-moulded or else deposited on a substrate. Once the composition has been converted into an article, for example into a sheet or bar, it is provided with at least two electrodes that serve as the power lead-in and return, respectively. The composition may also be placed between two conducting plates that serve as the power lead-in and return, respectively.
摘要:
The present invention relates to a composition comprising, by weight, the total being 100%: A) 40 to 80% of PVDF; B) 10 to 40% of PMMA; and C) 10 to 40% of a conductive filler. This composition has a PTC effect and is advantageously used in the form of a film (paint) covering a substrate. The composition of the invention is dissolved in a solvent and then spread over a substrate and the solvent evaporated. The metal terminals for connection to the electrical circuit may be placed at the ends of the coating before or after application. The invention also relates to a composite, namely the substrate covered with the PTC composition described above.