Patent ID: 9551947
Date: 2017-01-24
CPC Classifications: G03G

Claim:
1. A magnetic toner comprising magnetic toner particles and an inorganic fine powder; each of the magnetic toner particles contains a binder resin, a magnetic body, and a release agent, wherein the magnetic body comprises magnetic iron oxide, and in a stress relaxation measurement using a rotating plate rheometer, the magnetic toner exhibits a yield value A at 25° C. of at least 3×10 wherein, with respect to a radius of gyration (Rw) and the weight-average molecular weight (Mw) of the tetrahydrofuran (THF)-soluble fraction of the magnetic toner as measured using size exclusion chromatography with a multiangle laser light scattering (SEC-MALLS), i) the weight-average molecular weight (Mw) is from 6,000 to 24,000, and ii) the weight-average molecular weight (Mw) and the radius of gyration (Rw) satisfy the following equation (1): wherein the melting point of the release agent is from at least 50° C. to 83° C., wherein the magnetic body is a treated magnetic body that has been surface treated in use of a silane compound with the following general formula (A): where R represents an alkoxyl group, m represents an integer from at least 1 to not more than 3, Y represents an alkyl group, n represents an integer from at least 1 to not more than 3, and m+n=4, and wherein the binding resin has a branching structure provided by use of a polymerization initiator, the polymerization initiator being an azo-type, diazo-type, or peroxide-type polymerization initiator.