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. 13, 2006
Filed:
Mar. 02, 2001
Katsuyuki Tanabe, Tokyo, JP;
Kouhei Mitsuhashi, Tokyo, JP;
Katsuyuki Tanabe, Tokyo, JP;
Kouhei Mitsuhashi, Tokyo, JP;
Nittetsu Mining Co., Ltd., Tokyo, JP;
Abstract
Silica-calcium carbonate composition particles having the characteristics of both synthetic silica and calcium carbonate are described along with paper having the particles internally filled therein and a method for making the particles. In the carbonation reaction, which typically involves a step of forming calcium carbonate, while agitating a calcium hydroxide slurry, a mixed gas of carbon dioxide and air is introduced thereinto and synthetic silica, such as colloidal silica or the like, is added before the carbonation rate arrives at 95% but after commencement of the carbonation reaction, followed by further introduction of the mixed gas to continue the carbonation reaction and completion of the carbonation reaction at the time when the pH of the slurry reaches 7, thereby providing the composite particles.