Vinylidene fluoride based resin porous hollow yarn and method for production thereof
US7569145B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 24, 2004 |
| Grant date | Aug 4, 2009 |
| Priority date | — |
| Expiry date | Sep 24, 2024 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D2325/20
- WIPO fieldChemical engineering
- WIPO sectorChemistry
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 3×105, having a water permeation rate F (m3/m2·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+F0 (formula 1) and satisfying requirements (a)-(d) shown below: (a) a average slope C (/day) of: −20≦C≦0, (b) an intercept (basic permeability) F0 (m3/m2·day) of: F0≧30, (c) a relation between F0 (m3/m2·day) and an average pore diameter P (μm) according to half-dry method of F0/P≧300, and (d) an outer diameter of at most 3 mm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.