Microporous polyethylene membrane, its production method, and battery separator
US8802273B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 14, 2006 |
| Grant date | Aug 12, 2014 |
| Priority date | — |
| Expiry date | Jun 29, 2027 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/249979
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A microporous polyethylene membrane made of a polyethylene resin having a ratio (mass-average molecular weight/number-average molecular weight) of 5 to 300 and comprising 1% or more by mass of ultra-high-molecular-weight polyethylene having a mass-average molecular weight of 7×105 or more, the microporous polyethylene membrane comprising (a) a coarse-structure layer having an average pore diameter of more than 0.04 μm, which is formed on at least one surface, and (b) a dense-structure layer having an average pore diameter of 0.04 μm or less, an area ratio of the coarse-structure layer to the dense-structure layer in a membrane cross section being 0.1 to 0.8.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.