Microporous material resistant to capillary collapse
US6461724B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 30, 1999 |
| Grant date | Oct 8, 2002 |
| Priority date | — |
| Expiry date | Aug 30, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/249981
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Microporous material comprising a polypropylene polymer having at least 20 percent crystallinity; and a compatible, amorphous, glassy polymer, wherein said polymers are miscible in a compound when heated above the melting temperature of the polypropylene polymer and wherein a polypropylene polymer phase separates from the compound when cooled below the crystallization temperature of the polypropylene polymer. Microporous material is made by a thermally induced phase separation process using a compound such as mineral oil to form one phase containing both polymers. The pores of the microporous material resist collapse during processing. Membranes made of this material are useful as battery separators having a good combination of strength, porosity, and ionic resistance when imbibed with an electrolyte.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.