Breathable, non-porous polyurethane film prepared from a low molecular weight difunctional compound, a polyethylene glycol and a diisocyanate
US4367327A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 21, 1981 |
| Grant date | Jan 4, 1983 |
| Priority date | — |
| Expiry date | Jul 21, 2001 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31551
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Clothing weatherproofed by being coated with plastics material of low permeability to water vapor is uncomfortable to wear. The present invention provides a breathable polyurethane film for coating on fabrics to make them waterproof. The film comprises a hard segment formed by reaction of a low molecular weight difunctional compound with excess diisocyanate to form a prepolymer and a soft segment provided by polyethylene glycol with which the prepolymer is reacted in a stoichiometric amount. If desired the film can be formed by reacting the polyethylene glycol with excess diisocyanate to form a prepolymer which is then reacted with a stoichiometric amount of a low molecular weight difunctional compound. The mechanical properties of the film can be improved by cross linking with a cross linking agent such as a triisocyanate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.