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:
Apr. 04, 2006
Filed:
Jul. 30, 2003
Nobuyoshi Sugahara, Shizuoka, JP;
Takaaki Kohtaki, Shizuoka, JP;
Yasuhiro Ichikawa, Shizuoka, JP;
Tetsuya Ida, Shizuoka, JP;
Kazuhiko Hayami, Shizuoka, JP;
Nozomu Komatsu, Shizuoka, JP;
Nobuyoshi Sugahara, Shizuoka, JP;
Takaaki Kohtaki, Shizuoka, JP;
Yasuhiro Ichikawa, Shizuoka, JP;
Tetsuya Ida, Shizuoka, JP;
Kazuhiko Hayami, Shizuoka, JP;
Nozomu Komatsu, Shizuoka, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
To provide a black toner having excellent charging property and transferring property against a severe environmental change. The black toner includes toner particle containing at least a binder resin, carbon black and a releasing agent, wherein: the toner particles have a weight-average particle diameter of 3.5 to 8.0 μm; total amount of acid value and hydroxyl value of the toner is 30 to 75 mgKOH/g; average circularity of particles contained in the toner having circle-equivalent diameter of 2 μm or more is 0.915 to 0.960; loss tangent tan δ (10to 10Hz) of the toner is represented by the following expression:tan δ(10to 10Hz)≦0.0060where the loss tangent tan δ is represented by ∈″/∈' where ∈″ denotes dielectric loss factor and ∈′ denotes dielectric constant, and tan δ (10to 10Hz) denotes the loss tangent in a frequency range of 10to 10Hz; and a ratio of tan δ (10Hz) to tan δ (5×10Hz) is represented by the following expression:1.05≦tan δ(10Hz)/tan δ(5×10Hz)≦1.40where tan δ (10Hz) denotes loss tangent at the frequency of 10Hz and tan δ (5×10Hz) denotes loss tangent at the frequency of 5×10Hz.