Microporous composite sheet material
US7972981B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 11, 2003 |
| Grant date | Jul 5, 2011 |
| Priority date | — |
| Expiry date | Mar 11, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T442/681
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A moisture vapor permeable, water impermeable composite sheet material is provided which is suitable for use as a housewrap material, and is also useful for other applications such as tarpaulins, or as covers for automobile, boats, patio furniture or the like. The composite sheet material includes a nonwoven substrate and an extrusion-coated polyolefin film layer overlying one surface of the substrate. The nonwoven substrate is comprised of polymeric fibers randomly disposed and bonded to one another to form a high tenacity nonwoven web. The nonwoven substrate has a grab tensile strength of at least 178 Newtons (40 pounds) in at least one of the machine direction (MD) or the cross-machine direction (CD). The extrusion coated polyolefin film layer is intimately bonded to the nonwoven substrate. The film layer has micropores formed therein to impart to the composite sheet material a moisture vapor transmission rate (MVTR) of at least 35 g/m2/24 hr. at 50% relative humidity and 23° C. and a hydrostatic head of at least 55 cm. In one embodiment, the nonwoven substrate comprises a spunbonded nonwoven fabric formed of randomly disposed substantially continuous polypropylene filaments. Th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.