| abstract |
A PTC conductive composite material and the overcurrent protection device made of the material are disclosed. The PTC conductive composite material includes: (a) A matrix of crystalline polymer material at least, occupies 20%-70% of the volume fraction of the PTC conductive composite material, (b) One kind of conductive filler occupies 30%-80% of the volume fraction of the material. The solid solution conductive filler is uniformly dispersed in the polymer material, whose average particle size ranges from 0.1 μm to 10 μm, and the volume resistivity is no more than 300 μΩ·cm. The overcurrent protection device prepared by using the PTC conductive composite material as described above includes two metal foils, which are made into a sandwich, separated by a layer of the PTC conductive composite material. n And the advantages of the overcurrent protection device of the invention are low resistance, good reproducibility of resistance and well PTC intensity. |