BEAD-LIKE HOLLOW PARTICLES, METHOD FOR PRODUCING SAME, AND FRICTION MATERIAL USING THE BEAD-LIKE HOLLOW PARTICLES

摘要

The present invention provides bead-like hollow particles and an easy and convenient method for producing the same, and a friction material using the bead-like hollow particles. The particles are bead-like hollow particles comprising odd-shaped particles composed of a metal oxide as a main component and having at least one of a through hole and non-through hole in a surface; the method is a producing method for the bead-like hollow particles, which comprises spraying and drying a suspension of a particulate biological material and a particulate metal oxide by a two-fluid nozzle spray dryer to obtain a powder composed of the particulate biological material as a core and a layer of the particulate metal oxide as a shell, and heating the obtained powder; and the friction material is a friction material using the hollow particles.