Porous membrane of vinylidene fluoride resin and process for producing the same
US7351338B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 10, 2004 |
| Grant date | Apr 1, 2008 |
| Priority date | — |
| Expiry date | Apr 6, 2025 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/29
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
There is provided a porous membrane of vinylidene fluoride resin which has pores of appropriate size and distribution and also excellent mechanical strength represented by tensile strength and elongation at break and is useful as a microfiltration membrane or a separator for batteries. The porous membrane of vinylidene fluoride resin is characterized by the presence in mixture of a crystalline oriented portion and a crystalline non-oriented portion as confirmed by X-ray diffraction, and is produced by subjecting a melt-extruded composition obtained by mixing a vinylidene fluoride resin having a molecular weight distribution which is appropriately broad and high as a whole with a plasticizer and a good solvent for vinylidene fluoride resin, to cooling for solidification from one surface, extraction of the plasticizer and stretching.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.