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:
Nov. 25, 2008
Filed:
Jun. 08, 2005
Yasuhiro Tada, Ibaraki-Ken, JP;
Takeo Takahashi, Ibaraki-Ken, JP;
Masayuki Hino, Ibaraki-Ken, JP;
Shingo Taniguchi, Fukushima-Ken, JP;
Kenichi Suzuki, Ibaraki-Ken, JP;
Toshiya Mizuno, Ibaraki-Ken, JP;
Yasuhiro Tada, Ibaraki-Ken, JP;
Takeo Takahashi, Ibaraki-Ken, JP;
Masayuki Hino, Ibaraki-Ken, JP;
Shingo Taniguchi, Fukushima-Ken, JP;
Kenichi Suzuki, Ibaraki-Ken, JP;
Toshiya Mizuno, Ibaraki-Ken, JP;
Kureha Corporation, Tokyo, JP;
Abstract
A vinylidene fluoride resin having a weight-average molecular weight as relatively high as 300,000 or higher is mixed with a plasticizer and good solvent for the vinylidene fluoride resin to obtain a composition. A molten extrudate of the composition in a hollow-fiber membrane state is contacted, on its outer side, with a cooling liquid inert to the vinylidene fluoride resin to thereby cool the extrudate. During the solidification, the vinylidene fluoride resin is moderately and mildly crystallized. Thus, a hollow-fiber porous vinylidene fluoride resin membrane is produced which has a high crystallinity represented by an enthalpy of crystal melting 58 J/g or higher. The hollow-fiber porous membrane obtained is excellent in mechanical strength represented by tensile strength and elongation at break and in chemical resistance. It is effectively used as a water microfiltration membrane.