Konica Corporation

Tsuneo Daidoji

Masafumi Uchida

Kishio Tamura

A carrier for electrophotographic use is disclosed. The carrier has a resin-coated layer on the surface of the core member. The resin forming the coated layer contains a polymer prepared by copolymerizing an alicyclic methacrylate monomer and a chain-type methacrylate monomer. A high quality image can stably be obtained extending over a long period of time when the carrier is used in continuous developing.

Carrier for electrophotographic use

A method for preparing a carrier for developing an electrostatic charge image, wherein the carrier comprises core particles each having thereon a resin coated layer, and a volume base average particle diameter D50 of the core particles is within the range of 40 to 80 .mu.m, and 5 wt % or less of the core particles have a volume base average particle diameter D50.times.1.2 .mu.m or more and 5 wt % or less of the core particles have a volume base average particle diameter D50.times.0.7 .mu.m or less, comprising the steps of forming a mixture of the core particles and coagulated resin particles; applying an impact force repeatedly to said mixture to coat said coagulated resin particles on said core particles; wherein a volume base average particle diameter D50 of the coagulated resin particles is within the range of 0.5 to 20 .mu.m, and a ratio of a volume base 25% particle diameter of the coagulated resin particles/a volume base average particle diameter D50 of the coagulated resin particles is within the range of 0.5 to 1.0, and a ratio of a volume base 75% particle diameter of the coagulated resin particles/a volume base average particle diameter D50 of the coagulated resin particles is within the range of 1.0 to 1.8.

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Hachioji, Japan

Tsuneo Daidoji