To provide an electrophotographic toner, an electrophotographic developer and a method of forming an image so that an image of excellent picture quality can be formed, the toner has excellent thermal storage property, enough offset resistance during fixing and excellent low temperature fixing property, and form the viewpoints of storage and transfer of a printed material, an image with good stability for a long term against heat or load can be formed.
The electrophotographic toner contains a binder resin, a coloring agent and a resin with high melt viscosity having 300 to 3000 weight average mol.wt. and 103 to 106 (Pa.s) melt viscosity η at 140°C. The average of the shape factor expressed by formula (1): SF1=ML2×100 π/4A ranges 105≤SF1≤140. In the formula, ML is the maximum length of the diameter of electrophotographic toner particles, A is the projected area of the particle of the electrophotographic toner. The electrophotographic developer contains the above toner and is used for the method of forming an image.
FUKUDA HIROYUKI
SUZUKI CHIAKI
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