Kanto Denka Kogyo Co., Ltd.

Yukinari Oguma

Hidehiko Iinuma

Masatomo Hayashi

Yuki Goto

Natsuki Matsuura

Kazuto Yoshinari

An additive for lubricants containing, a ZrOparticle coated with a silane coupling agent, and a dispersion medium for the ZrOparticle, wherein a BET specific surface area of the ZrOparticle coated with the silane coupling agent obtained by removing the dispersion medium is 40% or more of a BET specific surface area of the ZrOparticle before coating with the silane coupling agent.

Additive for lubricants

This invention provides an Mg-based ferrite having a high dielectric breakdown voltage and a saturation magnetization suitable for electrophotographic development, a carrier containing the ferrite, and an electrophotographic developer containing the carrier. The Mg-based ferrite material of this invention comprises Li, Na, K, Rb, Cs, Ca, Sr, Ba, Y, La, Ti, Zr, Hf, V, Nb, Ta, Al, Ga, Si, Ge, P, Sb, Bi or a combination thereof. The Mg-based ferrite material has a saturation magnetization of 30 to 80 emu/g, and a dielectric breakdown voltage of 1.5 to 5.0 kV. The Mg-based ferrite material can realize high image quality, and be in compliance with environmental regulations.

Growing community of inventors

Shibukawa, Japan

Yukinari Oguma