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.

Date of Patent:
Jul. 07, 2015

Filed:

Jun. 08, 2011
Applicants:

Kunihiko Inui, Settsu, JP;

Yoshiyuki Shibuya, Yuki, JP;

Shunji Kasai, Settsu, JP;

Taku Yamanaka, Settsu, JP;

Inventors:

Kunihiko Inui, Settsu, JP;

Yoshiyuki Shibuya, Yuki, JP;

Shunji Kasai, Settsu, JP;

Taku Yamanaka, Settsu, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B01D 39/16 (2006.01); B01D 46/54 (2006.01); B01D 46/52 (2006.01);
U.S. Cl.
CPC ...
B01D 39/1692 (2013.01); B01D 46/543 (2013.01); B01D 2275/10 (2013.01); B01D 2239/1291 (2013.01); B01D 46/521 (2013.01); B01D 46/54 (2013.01); B01D 2239/0654 (2013.01); B01D 2239/1208 (2013.01); B01D 2239/1216 (2013.01);
Abstract

A filter medium includes a porous film and a support material supporting the porous film. The porous film includes polytetrafluoroethylene, has an average pore diameter of at least 2.5 μm, and has a porosity of at least 95%. A pressure loss is less than 100 Pa when air is passed through the filter medium at a velocity of 5.3 cm/sec. A collection efficiency of NaCl particles is at least 95% when air including NaCl particles with a particle diameter of 0.3 μm is passed through the filter medium at a velocity of 5.3 cm/sec. A PF value is at least 30, where PF={−log [(100−collection efficiency (%))/100]/pressure loss (Pa)}×1000. A dust holding capacity of polyalphaolefin particles held in the filter medium is at least 15 g/mwhen air including polyalphaolefin particles with a count median diameter of 0.25 μm is continuously passed through the filter medium at a velocity of 5.3 cm/sec and pressure loss reaches 300 Pa.


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