Magnetic responsiveness composite material and composition including the composite material

Abstract

There is provided a magnetic responsiveness composite material capable of increasing viscosity by applying a magnetic field when compounded together with a liquid in a composition. The magnetic responsive composite material comprises first particles as core particles composed of a nonmagnetic inorganic material and second particles composed of a magnetic material adhering to at least a part of surfaces of the first particles. A lipophilic treatment agent is applied to at least a part of surfaces of the second particles. The second particles satisfy a relationship of having a smaller average particle diameter than that of the first particles. A lipophilic treatment agent is preferably at least one kind selected from coupling agents and surfactants.

Dependencies are inferred from the claim text.