Magnetic toner, and image forming method
AssigneeCanon Kabushiki Kaisha
InventorsMichihisa Magome, Eriko Yanase, Atsushi Tani
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Abstract
A magnetic toner is provided having at last a binder resin and a magnetic material and having a weight-average particle diameter of 3 μm to 10 μm. The magnetic material has been surface-treated with a low-softening substance (A), and has a compressibility of 35 or more which can be calculated according to a specific expression. The softening point of the magnetic toner is from 40° C. to 85° C. in measurement by a flow tester. The magnetic toner has a resin component containing 1% to 60% by weight of a tetrahydrofuran-insoluble matter. This magnetic toner is superior in low-temperature fixing performance and has good fixing performance in a broad fixing range.
Claims14
A magnetic toner comprising:
- at least a binder resin and a magnetic material and having a weight-average particle diameter of from 3 mm to 10 mm, wherein;
- said magnetic material produced is by treating surfaces of magnetic fine particles with a coupling agent and, thereafter, with a low-softening substance (A) comprising a wax or a crystalline polyester having an endothermic peak from 80° C. to 150° C. measured by differential scanning calorimetry, and having a compressibility of 35 or more which is found from the following expression (1):
- compressibility=(1−(apparent density/tap density))×100 (1);
- said magnetic material (a) is present in amounts of 10 to 200 parts by weight based on 100 parts by weight of the binder resin and (b) has been treated with said low -softening substance (A) in amounts from 0.3 to 15 parts by weight based on 100 parts by weight of the magnetic fine particles;
- said magnetic toner has a softening point Ts of from 40° C. to 85° C. in measurement by a flow tester;
- and
- said magnetic toner has a resin component containing 1% by weight to 60% by weight of a tetrahydrofuran-insoluble matter.
Dependencies are inferred from the claim text.