Lightly cross-linked polyurethane hydrogels based on poly(alkylene ether) polyols
US3939123A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 18, 1974 |
| Grant date | Feb 17, 1976 |
| Priority date | — |
| Expiry date | Jun 18, 1994 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S521/905
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
Polyurethane hydrogels of high water swellability comprising lightly crosslinked polymers of isocyanate terminated prepolymers which are the reaction production of (i) poly(alkyleneoxy) polyols with (ii) organic diisocyanates that has been lightly crosslinked with (iii) water or an organic polyamine. PAC BACKGROUND OF THE INVENTION The use of fibrous materials as absorbents for moisture is a well known, widespread practice. In this application many of the natural and synthetic fibers have been used and extensive efforts have been made to improve the absorption properties of the materials. One of the major deficiencies of the natural and synthetic materials heretofore used has been the tendency for them to release the absorbed moisture when pressure has been applied to the moisture containing material. The fact that pressure causes the absorbed fluid to be expelled from the fibers is known as reversible absorption. For many applications, however, irreversible absorption is desired, for example, in surgical dressings, diapers, bed pads, catamenials, and the like, whereby the absorbed moisture is retained in the absorbent material under an applied pressure. Within the past few years r…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.