WET FRICTION MATERIAL

PROBLEM TO BE SOLVED: To reduce a drag torque, while being greater in a disengagement feature and a positive μ-V slope characteristic by keeping a pore diameter large without generating strength reduction or increase in permanent set quantity, in a wet friction material. SOLUTION: By adding small-particle-diameter inorganic filler 2, the inorganic filler 2 attaches between fibers 3 and an effect to improve strength of friction material substrates 1 is obtained by connecting the fibers 3 when an impregnated resin is hardened. Moreover, by keeping true specific gravity of the inorganic filler 2, compounded capacity becomes small and a pore diameter 5 of the friction material substrates 1 can be secured without being filled in pores of the friction material substrates 1 with the inorganic filler 2. As a result, it makes faster to absorb ATF (Automatic Transmission Fluid) from a friction surface. Therefore, it improves the disengagement feature and the positive μ-V slope characteristic, while reducing the drag torque. COPYRIGHT: (C)2009,JPO&INPIT