Image forming method employing toner containing higher and lower molecular weight polymer components

摘要

An electrophotographic toner composition suitable for heat-fixation and showing good storage characteristics is constituted by polymer components, a colorant and a metal-containing organic compound. The toner composition shows a melt index (at 125 DEG C., 10 kg-load) of 5-25 g/10 min., and the polymer components are characterized by (a) containing substantially no THF (tetrahydrofuran)-insoluble content, (b) including a THF-soluble content thereof providing a GPC (gel permeation chromatography) chromatogram showing i) a main peak in a molecular weight region of 2x103-3x104, and a sub-peak or shoulder in a molecular weight region of at least 105, and ii) an areal percentage of 3-10% in a molecular weight region of at least 106, and (c) including a polymer component (H) in a molecular weight region of at least 105 obtained by polymerization using a polyfunctional polymerization initiator and a mono-functional polymerization initiator.