MAGNETIC FLUID

摘要

This invention provides a magnetic fluid which is diversified in hue and stable in the electric fields. The magnetic fluid of this invention is composed of a dispersion of ferromagnetic particles dispersed by a surfactant, and a colorant having the same charge as the dispersing medium in said dispersing medium. The dyes effective for use in this invention are the nonionic azo dyes, anthrquinone dyes and metal-containing dyes, and the pigments useful in this invention are the organic or inorganic pigments treated so as to have an isoelectric point in the dispersing medium. A magnetic fluid having black color or other desired hues can be obtained by properly selecting the dye and/or pigment. The magnetic fluid of this invention exhibits its excellent properties particularly when used as a recording material.