Breathable microporous film and methods for making it
US4923650A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 27, 1988 |
| Grant date | May 8, 1990 |
| Priority date | — |
| Expiry date | Jul 27, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S264/06
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A soft, flexible, microporous film is provided having high tensile strength and good air and water vapor transmission rates therethrough while being substantially impenetrable to liquid water. This film is prepared by stretching a casting of a composition of a polyolefin and high levels of CaCO.sub.3 or glass beads and calcium stearate in two directions from 1.5-7 times in each direction to produce a film having a Gurley porosity of from 0.1 to 85 seconds. This film is especially useful for disposable items such as feminine panty liners, diapers, bed sheets, and hospital gowns. When glass beads are substituted for the CaCO.sub.3, the film is useful for battery separators.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.