To obtain a filler capable of providing a wet-type frictional material excellent in oil resistance and heat resistance, and also manifesting a stable and high friction coefficient by using a specific composite rubber powder for a rubber powder as its major component.
This filler for a wet-type frictional material capable of providing a wet-type frictional material together with a fibrous component, a thermosetting resin and a friction adjusting agent, contains a composite rubber powder consisting of an acrylic rubber (hereinafter AC) with a nitrile rubber (hereinafter NBR) or a styrene-butadiene rubber (hereinafter SBR) for a rubber powder as its major component. The composite rubber powder is preferably obtained by mixing the latexes of each of rubbers and adding an coagulating agent such as an aqueous solution of aluminum sulfate. Further, the mixing ratio of NBR or SBR to AC is preferably 10-90wt.%.
SUZUKI YASUYOSHI
ARAI HARUTOSHI
NISHIMURA MIKIO
Next Patent: FRICTIONAL MATERIAL COMPOSITION