| abstract |
The invention relates to a method for producing hydrophilic polyurethane foams, wherein in a step A) isocyanate-functional prepolymers are produced, in a step B) the free NCO groups of the prepolymers are completely or partially reacted with isocyanate-reactive hydrophilising agents so as to lengthen chains, in a step C) the prepolymers are dispersed in water before, during or after step B), wherein potentially ionic groups optionally contained therein are converted into the ionic form by partial or complete reaction with a neutralising agent, in a step D) the dispersion from step C) is mixed with foaming additives, in a step E) the mixture from step D) is foamed and in a step F) the foam from step E) is dried, wherein the mixture from step D) is stored for a period of at least 4 hours before the foaming process in step E). The invention further relates to a foam which can be obtained by the method and to the use thereof as a wound dressing. |