Invention Grant
- Patent Title: Developing material for electrophotography, process for preparation
- Patent Title (中): 电子照相显影材料,制备方法
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Application No.: US592752Application Date: 1984-03-26
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Publication No.: US4518674APublication Date: 1985-05-21
- Inventor: Shotaro Watanabe , Makoto Tomono , Goichi Yamakawa , Takeo Nishimura , Nobuo Takahashi
- Applicant: Shotaro Watanabe , Makoto Tomono , Goichi Yamakawa , Takeo Nishimura , Nobuo Takahashi
- Applicant Address: JPX Tokyo
- Assignee: Konishiroku Photo Industry Co., Ltd.
- Current Assignee: Konishiroku Photo Industry Co., Ltd.
- Current Assignee Address: JPX Tokyo
- Priority: JPX52-80061 19770705
- Main IPC: G03G9/08
- IPC: G03G9/08 ; B22F1/00 ; G03G9/083 ; G03G9/10 ; G03G9/107 ; G03G9/113 ; G03G15/08 ; G03G15/09

Abstract:
An iron powder developer carrier for electrophotography having at least the outer surface thereof coated with iron oxide. The iron oxide has a particle size of 50 to 200.mu., an apparent density of 1.5 to 2.5 g/cm.sup.3 and a specific surface area of 0.01 to 0.3 m.sup.2 /g.A process for the preparation of iron powder developer carriers for electrophotography, which comprises the steps of subjecting a starting iron powder to a primary calcination treatment in an inert gas atmosphere without using a binder, pulverizing and classifying said calcination product to prepare an intermediate iron powder, reducing the intermediate iron powder in a reducing atmosphere and washing the intermediate iron powder, and subjecting the intermediate iron powder to an oxidizing calcination treatment.
Public/Granted literature
- US5702440A Multifocal ophthalmic lens for dim-lighting conditions Public/Granted day:1997-12-30
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