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. 27, 2004
Filed:
Jun. 27, 2002
Hisao Okamoto, Tokyo, JP;
Yutaka Nakagawa, Tokyo, JP;
Yoshiyuki Zama, Tokyo, JP;
Koji Tsuchiya, Tokyo, JP;
Shotoku Takami, Tokyo, JP;
Yoshio Abe, Tokyo, JP;
Michiei Nakamura, Tokyo, JP;
Dainichiseika Color & Chemicals Mfg. Co., Ltd., Tokyo, JP;
Abstract
A finely divided pigment is formed of an aggregate of primary particles. A number of primary particles of not greater than 0.1 &mgr;m in particle size is at least 95% of an entire number of the primary particles, and a number of primary particles of greater than 0.1 &mgr;m in particle size is at most 5% of the entire number of the primary particles. The finely divided pigment can be produced by grinding a parent pigment (pre-division pigment) together with a water-soluble inorganic salt and a water-soluble organic solvent in a grinding machine at a temperature of from 30 to 90° C. for 2 to 6 hours under a load, and then removing the water-soluble inorganic salt and the water-soluble organic solvent. A coloring composition comprises a dispersing medium and the finely divided pigment dispersed in the dispersing medium. The coloring composition is, for example, an image recording agent for the ink-jet recording system, an image recording agent for the electronic printing or electrostatic recording system, or a coloring agent for forming color filter pixels.