Patent ID: 6653036
Filing Date: 2003-11-25
Classification: G03G

Abstract:
A magnetic toner comprising a magnetic toner particle containing at least a binding resin and a magnetic material;wherein the magnetic material comprises a magnetic iron oxide and contains 0.10% to 4.00% by weight of an element &agr; from the third period to the seventh period with an atomic number of 11 to 103 in the long-period Periodic Table and having an electronegativity of 0.1 to 2.5; the solubility S1 of the element &agr; in said magnetic material at an iron solubility of 0% to 20% lies in a range from 10% to less than 44%, the solubility S2 of the element &agr; in said magnetic material at an iron solubility of 80% to 100% lies in a range from 5% to less than 30%; and said magnetic material is selected from the group consisting of (i) a magnetic material containing at least 60% by number of multinuclear magnetic iron oxide particles based on magnetic iron oxide particles, (ii) a magnetic material containing at least 50% by number based on magnetic iron oxide particles of multinuclear magnetic iron oxide particles and at least 60% by number in total, based on magnetic iron oxide particles, of polyhedral magnetic iron oxide particles having faces at ridgeline portion of hexahedron and multinuclear magnetic iron oxide particles, (iii) magnetic material containing at least 50% by number based on magnetic iron oxide particles of multinuclear magnetic iron oxide particles and at least 60% by number in total, based on magnetic iron oxide particles, of polyhedral magnetic iron oxide particles having faces at ridgeline portion of octahedron and multinuclear magnetic iron oxide particles, and (iv) magnetic material containing at least 50% by number based on magnetic iron oxide particles of multinuclear magnetic iron oxide particles and at least 60% by number in total, based on magnetic iron oxide particles, of polyhedral magnetic iron oxide particles having faces at ridgeline portion of hexahedron, polyhedral magnetic iron oxide particles having faces at ridgeline portion of octahedron and multinuclear magnetic iron oxide particles.