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. 02, 2025
Filed:
Apr. 03, 2020
Nitto Denko Corporation, Osaka, JP;
Shunsuke Masaki, Osaka, JP;
Masaaki Mori, Osaka, JP;
NITTO DENKO CORPORATION, Osaka, JP;
Abstract
A filter medium of the present disclosure has a laminate structure composed of a first polytetrafluoroethylene (PTFE) porous membrane, a first air-permeable supporting member, a second PTFE porous membrane, and a second air-permeable supporting member laminated in this order. The first PTFE porous membrane constitutes an exposed surface of the filter medium. A ratio of a transmittance of the first PTFE porous membrane to a transmittance of the second PTFE porous membrane is 100 or more. The filter medium of the present disclosure is a filter medium which includes the PTFE porous membranes, from which dust deposited on a surface over a period of use can be easily removed, and which has excellent reusability demonstrated by reduction of a filtration performance decrease caused by removal of dust.