Breathable multilayer films with breakable skin layers
US6638636B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 28, 2001 |
| Grant date | Oct 28, 2003 |
| Priority date | — |
| Expiry date | Jan 5, 2022 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T442/678
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A breathable multilayer film having a breathable core layer and at least one skin layer is disclosed. The core layer prepared by from a mixture containing a thermoplastic polymer and a particulate filler and the skin layer or layers are prepared from a mixture of at least two incompatible polymers and a polymer which compatiblizes the incompatible polymers. The addition of the compatiblizer in the skin layer improves the film forming consistency. In addition, the core layer contains voids around the particulate filler and the skin layer or layer has cracks or voids, which provides breathability to the multilayer film. Stretching of the film after the layers are coextruded together forms the voids and/or cracks. The multilayer film of the present invention can be laminated with woven and nonwoven materials and the multilayer film of the present invention, whether or not the films are laminated with other materials, are useful in a wide variety of personal care products, medical garments and other product in which breathability is desired.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.