METHOD OF MANUFACTURING FLEXIBLE POLYURETHANE FOAM HAVING VISCOELASTICITY AND STRUCTURAL ACOUSTIC DAMPING CHARACTERISTIC AND NEW POLYOXYALKYLENE/ POLYOL MIXED COMPOSITION WHICH CAN BE USED THEREFOR

摘要

The invention relates to a process for the production of flexible, soft polyurethane foams having viscoelastic, structure borne soundproofing properties in a temperature range of from -20 DEG C to +80 DEG C, by reacting a) a polyoxyalkylene-polyol mixture containing ai) a block polyoxypropylene-polyoxyethylene-polyol mixture having a hydroxyl number of from 14 to 65 and containing from 2 to 9 % by weight, based on the weight of the polyoxypropylene units, of terminally bonded ethylene oxide units, and prepared by anionic polymerisation at elevated temperature of 1,2-propylene oxide onto an initiator molecule mixture having a mean functionality of from 2.3 to 2.8 comprising water and glycerol and/or trimethylolpropane, and polymerisation of ethylene oxide onto the resultant polyoxypropylene adduct, and aii) at least one difunctional and/or trifunctional polyoxypropylene-polyoxyethylene-polyol containing from 60 to 85 % by weight, based on the total weight of polymerised alkylene oxide units, of oxyethylene units, and having a hydroxyl number of from 20 to 80, and b) optionally low-molecular-weight chain extenders with c) organic and/or modified organic polyisocyanates, in the presence of d) catalysts, e) blowing agents, preferably water, and optionally f) assistants and/or additives, and to the polyoxyalkylene-polyol mixtures (a) which can be used for this purpose.