Polyolefin-based microporous films via sequential cold and hot stretching of unannealed polypropylene copolymer films
US11680159B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 16, 2020 |
| Grant date | Jun 20, 2023 |
| Priority date | — |
| Expiry date | Jul 28, 2041 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E60/10
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Microporous polymer films and methods of making same are disclosed. The microporous polymer film comprises: one or more polypropylene copolymer, said polypropylene copolymer comprising one or more polypropylene homopolymer chain segments and one or more ethylene-containing copolymer chain segments; wherein the microporous polymer film comprises: (i) polypropylene homopolymer chain segments in total amount of from 50-82 wt. %, based on the weight of the microporous polymer film; (ii) one or more ethylene-containing copolymer chain segments in total amount of from 18-50 wt. %, based on the weight of the microporous polymer film, wherein at least a portion of the ethylene-containing copolymer chain segments comprises polymerized units of ethylene in an amount of at least 45 wt. %, based on the weight of the ethylene-containing copolymer chain segments.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.