| 摘要 |
The invention relates to a process for producing viscoelastic flexible polyurethane foams by reacting a) polyisocyanates with b) compounds having at least two hydrogen atoms which are reactive toward isocyanate groups, c) blowing agents, wherein the compounds having at least two hydrogen atoms which are reactive toward isocyanate groups b) comprise b1) from 0 to 90 parts by weight of at least one polyether alcohol consisting of exclusively propylene oxide units or propylene oxide units and not more than 50% by weight, based on the total weight of the alkylene oxides used, of ethylene oxide units in the polyether chain and having a nominal functionality of from 3 to 8 and a hydroxyl number in the range from 100 to 350 mg KOH/g, and b2) from 10 to 100 parts by weight of at least one graft polyol which can be prepared by in-situ polymerization of olefinically unsaturated monomers in at least one polyether alcohol which has exclusively propylene oxide units or propylene oxide units and not more than 50% by weight, based on the total amount of alkylene oxides used, of ethylene oxide units in the polyether chain, a nominal functionality of from 2 to 8 and a hydroxyl number in the range from 100 to 350 mg KOH/g, having a solids content of not more than 60% by weight, based on the total amount of polyols and solids used, where the sum of the parts by weight of b1) and b2) is 100.
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