MAGNETIC FLUID

摘要

This invention provides magnetic fluids having various hues. The magnetic fluids of this invention are constituted of a dispersion of colloidal coloring pigment particles and a dispersion of ferromagnetic particles. Said coloring pigment particles consist of an inorganic pigment such as cobalt blue, carbon black or the like or an organic pigment such as copper phthalocyanine, pigment scarlet or the like, and are dispersed as colloidal particles. By the selection of the coloring pigment particle, a magnetic fluid having a black hue or an arbitrary hue can be obtained. The magnetic fluids of this invention exhibit their excellent characteristic properties particularly when used as a recording material. For example, when the magnetic fluid of this invention is used as an ink for making a record on high quality paper, no color separation takes place on the paper surface between the magnetic particles and the coloring pigment particles, and the recorded image keeps its hue stably for a long period of time without color change.