ADDITIVE POWDERS FOR COATING MATERIALS OR PLASTICS

摘要

The present invention provides an additive powder for coating materials or plastics, comprising a particle of a metal or glass, comprised of a particle having a thickness of 0.5 to 5 .mu.m, a minor axis/major axis of from 5 to 500 .mu.m, an aspect ratio (ratio of the major axis to the thickness) of not less than 5, and a ratio of the minor axis to the major axis, of from 1 to 10, and having the shape of a leaf as a whole. This powder can be prepared by melting a metal or glass, bringing the resulting melt to flow out from a nozzle and jetting a gas to the melt to form droplets of the melt, and bringing said droplets, before they solidify, to collide against the surface of a rotating cooling member having the shape of an cone or horn and provided in the direction of the flow of said droplets, followed by cooling to effect solidification. This powder can readily cause the leafing phenomenon when added in coating materials and coated, and hence the coating surface can be effectively covered with the powder, so that it can impart superior corrosion resistance and weathering resistance as compared with conventional powders. It can also impart superior electromagnetic shielding properties when added in plastics or rubbers.