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AssigneeToda Kogyo Corporation
InventorsShinji Uemoto, Hiromitsu Misawa, Ryo Iwai, Naoki Uchida, Koso Aoki, Kazuya Fujita, Kaori Kinoshita, Kazushi Takama, Eiichi Kurita
Estimating the term…
Black magnetic iron oxide particles having an average particle diameter of 0.05 to 2.0 μm and an electric resistance value at an applied voltage of 100 V of not less than 1×108 Ω·cm. Also a magnetic carrier for electrophotographic developer having spherical magnetic composite particles obtained by dispersing black magnetic iron oxide particles in a binder resin. The magnetic carrier has an electric resistance value R100 at an applied voltage of 100 V of 1×108 to 1×1014 Ω·cm, and an electric resistance value R300 at an applied voltage of 300 V which satisfies the relationship represented by the formula: 0.1≦R300/R100≦1.
Black magnetic iron oxide particles which comprise core particles and a surface layer formed on the respective core particles and which have an average particle diameter of 0.05 to 2.0 μm and an electric resistance value RM100 at an applied voltage of 100 V of not less than 1×108 Ω·cm.
Dependencies are inferred from the claim text.