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:
Jun. 15, 1999
Filed:
Aug. 04, 1997
Makoto Kanbayashi, Shizouka-ken, JP;
Masaaki Taya, Mishima, JP;
Ryoichi Fujita, Odawara, JP;
Wakashi Iida, Numazu, JP;
Tetsuya Ida, Mishima, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A magenta toner for developing electrostatic images is formed of a binder resin, and a quinacridone pigment providing an X-ray diffraction spectrum showing two peaks in a Bragg angle (2.theta.) region of 5-10 deg. The magenta toner has an improved light fastness, may have a desired hue comparable to a printing process ink and is suitably used for electrophotographic full-color image formation. The magenta toner may preferably be formed through a process including a first kneading step starting from wet blending of a binder resin and two paste pigments including quinacridone and 2,9-dimethylquinacridone, respectively, under mild conditions not causing crystal transformation to form a master batch and a second kneading step of diluting the master batch together with other additive.