摘要 |
<P>PROBLEM TO BE SOLVED: To provide bead-like hollow particles, a method for easily producing the particles, and a friction material using the bead-like hollow particles. <P>SOLUTION: The bead-like hollow particles are characterized by being composed of odd-shaped particles that are mainly formed from a metal oxide and have a through hole or non-through hole in the surface. The method for producing the bead-like hollow particles is characterized in that a suspension of a particulate biological material and a particulate metal oxide is spray dried with a two-fluid nozzle spray dryer and then the thus-obtained particles each having a core composed of the particulate biological material and a shell composed of a layer of the particulate metal oxide are subjected to a heat treatment. The friction material uses the above hollow particles. <P>COPYRIGHT: (C)2011,JPO&INPIT |