| 摘要 |
PROBLEM TO BE SOLVED: To provide new copper powder which enables a conductive film and a conductive membrane to be made sufficiently thin and moreover, despite comprising fine particles, enables conductivity to be secured with a small amount.SOLUTION: Provided is copper powder having a chlorine concentration of 5 to 150 wt ppm and a volume cumulative particle diameter D50 of 0.5 to 5.0 μm. Of all copper particles, 80 number% or more are accounted for by copper powder particles exhibiting a dendrite-like structure, where the particle has one main axis from which a plurality of branches extend askew to form a two-dimensionally or three-dimensionally grown dendrite-like structure, and where a number of branches relative to a long diameter L of the main axis, (number of branches)/(long diameter of main axis, L), is 3.0 to 20.0/μm. The copper powder has a specific surface area of 1.2 to 4.0 m/g as measured by a BET one-point method.SELECTED DRAWING: None |
