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:
Jan. 10, 1989
Filed:
Sep. 24, 1986
Toshiaki Nakahara, Tokyo, JP;
Ichiro Ohsaki, Kawasaki, JP;
Hisayuki Ushiyama, Hiratsuka, JP;
Masashi Kiuchi, Kawasaki, JP;
Masuo Yamazaki, Kawasaki, JP;
Yasuhide Goseki, Tokyo, JP;
Hisayuki Ochi, Tokyo, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An encapsulated toner is provided by coating core particles with an outer shell. The outer shell comprises, as predominant components thereof, vinyl polymers A and B of different molecular weights. More specifically, the ratio of the number-average molecular weight of the vinyl polymer A (Mn.sub.A) to that of the vinyl polymer B (Mn.sub.B) is in the range of 2 to 15. The vinyl polymers A and B respectively have a ratio of weight-average molecular weight to number-average molecular weight of 5 or less. Because of these specific molecular weight characteristics of the shell-constituting polymers, the durability and triboelectric charging characteristics of the encapsulated toner are improved. These effects are enhanced particularly when inorganic fine particles are attached to embedded in the surface or surface layer of the core particles.