MAGNETIC FUNCTIONAL FLUID, AND DAMPER AND CLUTCH USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a magnetic functional fluid capable of increasing viscosity more than conventional magnetic functional fluids, as compared at the same volume concentration of dispersed particles.SOLUTION: In a magnetic functional fluid, first ferromagnetic particles 1 and needle-like second ferromagnetic particles 2 are dispersed in a dispersion medium, the first ferromagnetic particles having an average particle size of 0.5-50 μm and the second ferromagnetic particles having a particle size smaller than that of the first ferromagnetic particles 1, a multi magnetic domain structure, and a length ratio between the major axis and the minor axis of 2 or more.