PROBLEM TO BE SOLVED: To provide an inorganic PTC material, which has resistivity lower than that of conventional ceramic PTC materials and from which disadvantages, such as low combustibility or low resistance restorability of a polymer PTC material is removed. ;SOLUTION: A mineral-metal composite showing PTC behavior at a tripping temperature between 40°C and 300°C contains an electrical insulating inorganic matrix, having room-temperature resistivity of at least 1×106 Ωcm and conductive particles which are scattered in the matrix in a state, where particles form a three-dimensional conductive network extends between the facing first and second surfaces of the composite. The composite has room-temperature resistivity of ≤10 Ωcm and high resistivity of at least 100 Ωcm. It is preferable to manufacture the conductive particles, using a Bi-based alloy containing at least 50 wt.% Bi and to adjust the average diameter Φave of the particles to 5-50 μm and to adjust 3σ-particle size distribution of the particles to 0.5 Φave-2.0 Φave.;COPYRIGHT: (C)2001,JPO
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