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. 11, 2000
Filed:
Dec. 18, 1998
Makoto Kanbayashi, Shizuoka-ken, JP;
Masaaki Taya, Mishima, JP;
Wakashi Iida, Numazu, JP;
Tetsuya Ida, Mishima, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A color toner has (i) color toner particles containing at least a binder resin and a colorant and (ii) an external additive. The color toner has a weight-average particle diameter of 5 to 8 .mu.m and a number-average particle diameter of 4.5 to 7.5 .mu.m, and contains 5 to 40% by number of particles having a particle diameter of 4 .mu.m or less in the number distribution of the color toner and 7% by volume or less of particles having a particle diameter of 10.08 .mu.m or more in the volume distribution of the color toner. The inorganic powder selected from the group consisting of a strontium titanate powder, a cerium oxide powder and a calcium titanate powder, and a hydrophobic fine alumina powder are externally added to the color toner particles as the external additives, the inorganic powder has a longitudinal average particle diameter of 0.2 to 2 .mu.m, and the hydrophobic fine alumina powder has a longitudinal average particle diameter of 0.005 to 0.1 .mu.m. The binder resin is a polyester resin crosslinked by a crosslinking agent. The color toner particles contain 0 to 20 mg/lg of a chloroform insoluble matter. The color toner has a storage modulus (G'.sub.130) of 2.times.10.sup.3 to 2.times.10.sup.4 [dyn/cm.sup.2 ] at a temperature of 130.degree. C. and a storage modulus (G'.sub.170) of 5.times.10.sup.3 to 5.times.10.sup.4 [dyn/cm.sup.2 ] at a temperature of 170.degree. C., and a value of G'.sub.170 /G'.sub.130 is in the range of 0.25 to 10.