Polyurethane films prepared from polyurethane dispersions
US6451908B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 13, 2000 |
| Grant date | Sep 17, 2002 |
| Priority date | — |
| Expiry date | Apr 13, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31551
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A process for preparing a polyurethane film comprising two steps is disclosed. The first step comprises preparing a nonionic prepolymer formulation, the prepolymer formulation comprising a diisocyanate, an active hydrogen containing material, and a monol. The second step comprises preparing an aqueous dispersion of the prepolymer, in the presence of a surfactant. Both steps occur in the substantial absence of an organic solvent. Also disclosed is a polyurethane film and an aqueous dispersion useful for preparing such films. The present invention has the advantage of having increased shear stability. The dispersions of the present invention do not settle or coagulate prematurely. Moreover, the films of the present invention do not include the dermal irritants which occur in natural rubber latex. The films and dispersions of the present invention are thus suitable for use in applications such as, for example, medical applications.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.