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. 28, 2026
Filed:
Aug. 19, 2020
Toyobo Co., Ltd., Osaka, JP;
Yoshiyuki Kitagawa, Otsu, JP;
Satoru Harada, Otsu, JP;
Keiko Sakaguchi, Otsu, JP;
Sadahito Goto, Osaka, JP;
TOYOBO MC CORPORATION, Osaka, JP;
Abstract
It is provided that an electret having excellent filtering performance and a filter using the electret even in a case where polyolefin resin and magnesium element are contained. An electret comprising a polyolefin resin and a nitrogen-containing compound, wherein 0.1 to 5 parts by mass of the nitrogen-containing compound is contained to 100 parts by mass of the polyolefin resin, a proportion of a magnesium element contained in the electret is 5 to 100 ppm, and a QF value represented by the following formula is not less than 1.00 mmAqwhen particles having particle diameters of 0.3 to 0.5 μm are to be collected.QF [mmAq]=−[ln(particle penetration(%)/100)]/[ventilation resistance (mmAq)]