PURPOSE: To obtain the title emulsion which can be directly formed into a film and can give easily a magnetic film, a magnetic paint, a magnetic toner or the like, by mixing a polymerizable vinyl monomer with a core material comprising a magnetic fluid formed by dispersing a magnetic material in water and polymerizing the monomer.
CONSTITUTION: A polymerizable vinyl monomer such as an alkyl (meth) acrylate of the formula (wherein R1 is H or CH3 and R2 is a 1W10C alkyl) is mixed with a magnetic fluid formed by dispersing fine magnetic particles such as magnetite or Mn-Zn ferrite (particle diameter of 60W150) obtained by a wet process in water with the aid of a dispersant such as an unsaturated fatty acid, an anionic or nonionic surfactant or neutralized maleinized polybutadiene and polymerized in the presence of a catalyst to obtain emulsified vinyl polymer particles (particle diameter of 0.1W0.8μ) containing the fine magnetic particles as cores.
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