The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 23, 1990
Filed:
Sep. 25, 1989
Ikutaroh Nagatsuka, Kanagawa, JP;
Yasuo Matsumura, Kanagawa, JP;
Masayuki Takeda, Kanagawa, JP;
Chiaki Suzuki, Kanagawa, JP;
Takayoshi Aoki, Kanagawa, JP;
Fuji Xerox Co., Ltd., Tokyo, JP;
Abstract
A developer carrier is disclosed, which has a core containing a binder resin and a magnetic powder, and a surface layer thereon containing a compound having a lower critical surface tension than the binder resin. This developer when used in a magnetic brush development process provides superior charge characteristics, resistance to environmental changes, and extended life. In another aspect, the invention relates to a developer carrier produced by a process of (a) melting a carrier composition containing a binder resin, a magnetic powder and a compound having a lower critical surface tension than the binder resin, (b) spraying the molten carrier composition to form droplets, and (c) cooling the droplets with a gas stream having a temperature lower than the melting point of the composition to form substantially spherical particles having a high surface smoothness.