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:
Sep. 14, 1999
Filed:
Mar. 13, 1998
Yoshio Nikawa, Yokohama-shi, JP;
Masaru Chino, Yokosuka-shi, JP;
Shinichi Kitahata, Toride, JP;
Keiko Kurata, Tsukuba, JP;
Hitachi Maxell, Ltd., Osaka, JP;
Other;
Abstract
A wave absorber which is light in weight, rich in flexibility and excellent in wave absorption characteristics in a microwave frequency range. The wave absorber in which composite carbon black particles including crystalline graphite and amorphous carbon black are dispersed into an insulating matrix. In the wave absorber, dispersion of the composite carbon black particles is adjusted so that a ratio (.rho./R) of a volume resistivity .rho. measured at frequencies of 30, 100 and 500 kHz to a measured DC volume resistivity R is in a predetermined range and a volume ratio of the composite carbon black particles having particle diameters of 10 nm to 200 nm to all the composite carbon black particles is in a range of 5% to 95%. Thereby, a wave absorber excellent in absorption characteristics is obtained.