Waterproof and breathable flat materials made from resin mixtures of thermoplastic polyurethane
US5840812A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 22, 1995 |
| Grant date | Nov 24, 1998 |
| Priority date | — |
| Expiry date | Nov 22, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31591
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The present invention relates to waterproof but breathable flat materials prepared from the melt from polymer resin mixtures consisting of at least two different melt processable polyurethanes, wherein the different thermoplastic polyurethanes have soft segments with different chemical constitutions, wherein the thermoplastic polyurethane which forms the matrix is a polyurethane with a ether based soft segment, wherein the ether segment has a carbon/oxygen atomic ratio of at least two and at most three and is present at a rate of 70-95 wt. % with reference to the total weight of thermoplastic polyurethanes used for melt processing to produce a flat material, and wherein the flat materials according to the invention have a higher permeability to water vapour, determined according to DIN 53 122, and a lower water absorption, determined according to DIN 53 495, method C, than flat materials made from one of the polyurethanes used for the polymer resin mixture.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.