| abstract |
An open-celled polyurethane foam formed from a composition comprising an active hydrogen-containing component, an organic polyisocyanate component having an average isocyanate functionality of 2.00 to 2.25, a surfactant component, and a catalyst. The foam has a thickness of about 6 to about 20 mils; a density of about 10 to about 50 pcf; an average cell diameter of about 25 to about 80 microns; and cell openings having an average diameter of about 1 to about 25 microns, wherein the ratio of average cell diameter to average cell opening diameter is about 3 to about 10; a water vapor transmission rate of greater than about 1000 grams per square meter per day, and which do not leak water or similar fluids. Such foams find particular utility as backings for bandages. |