PREPARATION OF FLEXIBLE, SOFT POLYURETHANE FOAMS HAVING VISCOELASTIC, STRUCTURE-BORNE SOUNDPROOFING PROPERTIES, AND POLYOXYALKYLENE-POLYOL MIXTURES WHICH CAN BE USED FOR THIS PURPOSE

摘要

The present invention relatesto a process for the preparation of flexible, softpolyurethane foams having viscoelastic, structure-bornesound-proofing properties in a temperature range of from -20°Cto +80°C by reactinga) a polyoxyalkylene-polyol mixture containingai) block polyoxypropylene-polyoxyethylene-polyolmixture having a hydroxyl number of from 14to 65 and containing from 2 to 9 % by weight ofterminal ethylene oxide units, based on theweight of the polyoxypropylene units, preparedby anionic polymerization, at elevatedtemperatures, of 1,2-propyleneoxide onto aninitiator molecule mixture having a meanfunctionality of from 2.3 to 2.8, comprising water andylycerol and/or trimethylolpropane, andpolymerization of acylene oxide onto the resultantpolyoxypropylene adduct, andaii) one or more difunctional and/or trifunctionalpolyoxypropylene-polyoxyethylene-polyolcontaining from 60 to 85 % by weight ofoxyethylene units, based on the total weight ofpolymerized alkylene oxide units, and having ahydroxyl number of from 20 to 80, andb) if desired low-molecular-weight chain extenders withc) organic and/or modified organic polyisocyanatesin the presence ofd) catalysts,e) blowing agents, preferably water, and, if desired,f) auxiliaries and/or additives,and to the polyoxyalkylene-polyol mixtures (a) which canbe used for this purpose.