NICKEL POWDER, METHOD FOR PRODUCING SAME, AND POLYMER PTC DEVICE USING SUCH NICKEL POWDER

摘要

There is provided a nickel powder which is inexpensive, has low electrical resistance when kneaded with a resin, has good weatherability, and can be used as an electrically conductive particles which are used as electrically conductive fillers for an electrically conductive paste. The nickel powder contains 1 - 20 % by mass of cobalt and the balance which comprises nickel and unavoidable impurities and which is formed of secondary particles of aggregated primary particles, which powder is characterized in that the powder has an average primary particle diameter being in 1.0 - 3.0 µm, a ratio Ã/d 1 of a standard deviation à of a primary particle diameter to the average primary particle diameter d 1 being 0.4 or less, an average secondary particle diameter being 5-60 µm, a tap density being 1.0 - 3.5 g/mL, and a specific surface area being 2.0 m 2 /g or less.