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:
Aug. 04, 2009
Filed:
Sep. 24, 2004
Yasuhiro Tada, Ibaraki-Ken, JP;
Takeo Takahashi, Ibaraki-Ken, JP;
Masayuki Hino, Ibaraki-Ken, JP;
Toshiya Mizuno, Ibaraki-Ken, JP;
Kosuke Abe, Ibaraki-Ken, JP;
Yasuhiro Tada, Ibaraki-Ken, JP;
Takeo Takahashi, Ibaraki-Ken, JP;
Masayuki Hino, Ibaraki-Ken, JP;
Toshiya Mizuno, Ibaraki-Ken, JP;
Kosuke Abe, Ibaraki-Ken, JP;
Kureha Corporation, Tokyo, JP;
Abstract
There is provided a porous hollow fiber of vinylidene fluoride resin which has a water permeation rate that is large per fiber and little dependent on the length, has a large treatment capacity per volume of a filtering module, and is therefore suitable as a microfilter element. That is, a porous hollow fiber, comprising a vinylidene fluoride resin having a weight-average molecular weight of at least 3×10, having a water permeation rate F (m/m·day) measured at a pressure difference of 100 kPa and at a water temperature of 25° C. in a range of test length L=0.2-0.8 (m) and expressed in a linear relationship with the test length L of: F=C·L+F(formula 1) and satisfying requirements (a)-(d) shown below: (a) a average slope C (/day) of: −20≦C≦0, (b) an intercept (basic permeability) F(m/m·day) of: F≧30, (c) a relation between F(m/m·day) and an average pore diameter P (μm) according to half-dry method of F/P≧300, and (d) an outer diameter of at most 3 mm.