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:
Dec. 12, 2000
Filed:
Jun. 12, 1998
Masanori Tanaka, Chuo-ku, JP;
Yuuji Washio, Chuo-ku, JP;
Mizusawa Industrial Chemicals Ltd., Tokyo, JP;
Abstract
The present invention provides the amorphous silica particles having a double structure of a core of the dense amorphous silica and a shell of the bulky amorphous silica, having a volume-based median diameter of from 1 to 5 .mu.m and containing not more than 10% by volume of fine particles having a particle diameter of not larger than 0.5 .mu.m. The amorphous silica particles of the double structure have constant particle diameters not only in the powdery state but also in a state where they are blended in a coating material or in a resin, without developing fine particles, exhibit excellent delustering action and antiblocking action, exhibit decreased abrading property, and exhibit excellent resistance against scars or abrasion.