Porous membrane structure and method
US6228477A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 12, 1999 |
| Grant date | May 8, 2001 |
| Priority date | — |
| Expiry date | Feb 12, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/269
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A composite membrane (12) comprising a membrane (16) with a structure of nodes (22) connected by fibrils (24). Surfaces of the nodes (22) and fibrils (24) define a plurality of interconnecting pores (26) that extend through the membrane (16) and between major sides (18, 20) of the membrane. The membrane (16) is made from an expanded polytetrafluoroethylene material which tends to tends to absorb oils and certain contaminating agents. The membrane (16) is moisture vapor transmissive, gas permeable and wind and liquid penetration resistant. A coating (28) is disposed on surfaces of the membrane (16) that define the pores (26). The coating (28) is made from an acrylic-based polymer with fluorocarbon side chains. The coating (28) is coalesced on surfaces of the nodes (22) and fibrils (24) to provide oil and certain contaminating agent resistance to the composite membrane (12) without completely blocking the pores (26) in the membrane (16). A method of treating a membrane (16) comprises the steps of providing a membrane (16) with a structure of node (22) and fibrils (24). Surfaces of the nodes (22) and fibrils (24) define a plurality of pores (26) extending through the membrane (16). Th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.