Patent ID: 7381467
Filing Date: 2008-06-03
Classification: C01G,C01P,C09K,G01N,Y10T

Abstract:
1. A composite particle comprising a ferromagnetic iron oxide particle, a fluorescent pigment particle and silica, and having an average particle size of 1 to 10 μm, a coercive force of 2.39 to 11.94 kA/m (30 to 150 oersted), saturation magnetization of 0.5 to 40 A.m a structure in which the ferromagnetic iron oxide particle and the fluorescent pigment particle are coated with silica, characterized in that the peak value of the wavelength of fluorescence from the composite particle is in the range of 350 to 750 nm when the composite particle is excited by light with a wavelength of 250 to 600 nm.