Patent ID: 8221622

Claim:
A polymer composite comprising secondary aggregates, the secondary aggregates being formed of clumped particles, the clumped particles being magnetic particles covered with a polymer, the magnetic particles having mean diameters of not less than 0.50 μm and not more than 100 μm, wherein C, D, X, E and F satisfy a relationship of 0.001 is less than or equal to F/(C×D×E) is less than or equal to X, where C (m 2 /g) represents a specific surface area of the magnetic particles, D (%) represents a content rate of the magnetic particles to a whole weight of the polymer composite, X (μm) represents a mean diameter of the magnetic particles, E (g/cm3) presents density of the polymer, and F (%) represents a content rate of the polymer to a whole weight of the polymer composite.