PURPOSE: To get carbonaceous frictional material that is superior in anti- oxidization and exhibits desirable character without lowering its friction character by forming refractory phosphate in empty voids in carbon material, after impregnating it with phosphate solution and applying heat treatment thereto over 500°C in a non-oxidizing atmosphere.
CONSTITUTION: Carbon material is impregnated with phosphate solution for applying heat treatment thereto over 500°C to form refractory phosphate in empty voids in carbon material. Then, by forming a refractory phosphate layer on the surface of the carbon material, its friction coefficient is increased. The reason is because the same function as friction adjusting agent is supposed to be provided, especially friction coefficient is increased under low load at low speed with low face pressure. And its oxidizing consumption is remarkably little, generated free phosphoric acid and the like is very little under high temperature due to friciton heat, and stable friction character is displayed. By giving anti-oxidization in such manner, it is possible to gain carbonaceous frictional material that has excellent characteristic under severe conditions.
IWAKI HIDEHIKO
UEMURA TAKEO
MURAKAMI SHIGERU
HANEZAWA HITOSHI
