| abstract |
A powder material for carbon electrode having an average particle diameter not exceeding 10 μm and an individual particle diameter of at least 0.7, where: the coefficient of variation of the particle size distribution expressed in the formula [ 1] following is not greater than 0.65: coefficient of variation of the particle size distribution> = (d84% - d16%) / (2 x average particle diameter) [1], where d84% and d16% represent particle sizes that show an accumulation where d84% and d16% represent particle sizes that have cumulative frequencies of 84% and 16% in a frequency distribution obtained by laser diffraction dispersion, respectively; the sphericity is at least 0.7; the average particle diameter denotes a value of a cumulative frequency of 50% in a frequency distribution obtained with a measurement method that uses a particle size measuring device by laser diffraction; the individual particle index denotes the number of individual particles / the total number of primary particles, where the index is determined by dispersion of the powder material for carbon electrode in water droplets, performing an observation under the optical microscope and a count of the total number of primary particles and the number of individual particles in a randomly selected visual field containing 300 primary particles, the individual particles being primary particles that do not form secondary agglomerates resulting from aggregation; and the sphericity denotes, in the case of randomly deciding a visual field containing 300 primary particles during the observation under the optical microscope, selecting 10 primary particles that have the lowest aspect ratios, that is, the minor axis / major axis ratios. , and measure the aspect ratios of their projected profiles as the respective of these 10 primary particles, the average of these 10 aspect ratios. |