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:
Nov. 02, 1999
Filed:
Aug. 18, 1998
Satoshi Matsunaga, Mishima, JP;
Koichi Tomiyama, Numazu, JP;
Yuichi Mizoh, Shizuoka-ken, JP;
Keita Nozawa, Shizuoka-ken, JP;
Minekazu Endo, Numazu, JP;
Tadashi Doujo, Numazu, JP;
Yoshihiro Ogawa, Numazu, JP;
Nene Shibayama, Mishima, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An electrophotographic toner is composed of at least a binder resin, a colorant, and a wax. The binder resin (a) comprises a polyester resin, a vinyl resin and a hybrid resin component comprising a polyester unit and a vinyl polymer unit, (b) has a THF (tetrahydrofuran)-soluble content (W1) of 50-85 wt. % and a THF-insoluble content (W2) of 5-50 wt. %, an ethyl acetate-soluble content (W3) of 40-98 wt. % and an ethyl acetate-insoluble content (W4) of 2-60 wt. %, a chloroform-soluble content (W5) of 55-90 wt. % and a chloroform-insoluble content (W6) of 10-45 wt. %, respectively after 10 hours of Soxhlet extraction with respective solvents, giving a ratio W4/S6 of 1.1-4.0, and contains a THF-soluble content providing a GPC (gel permeation chromatography) chromatogram exhibiting a main peak in a molecular weight range of 4000-9000, including 35.0-65.0% (A1) of a component haing molecular weights in a range of 500 to below 1.times.10.sup.4, 25.0-45.0% (A2) of a component having molecular weights in a range of 1.times.10.sup.4 to below 1.times.10.sup.5 and 10.0-30.0% (A3) of a component having molecular weights of at least 1.times.10.sup.5 giving a ratio A1/A2 of 1.05-2.00. The binder resin shows good dispersibility of wax and colorant.