The structural viscosity of the commercial and the synthesized aluminum distear-ate by the double decomposition method in aqueous solution was measured by capilary viscosimeter in benzene. The result was that aluminum stearate in benzene solution showed the structural viscosity at a low concentration of less than 0.5g./100cc., and that the time dependency of apparent viscosity in solution was assumed to be due mainly to the change of molecular weight of aluminum stearate.
By applying the double extrapolation method of 1/s→0 and c→0 into in η/r/c the intrinsic viscosity was calculated, and it gave exact information on the property of aluminum stearate. When the molar relationship of the intrinsic viscosity, [η_N] to aluminum and stearic acid was calculated, the maximum of [η_N] was found in a little smaller than 2 of St/Al.