Patent ID: 8362098
Filing Date: 2013-01-29
Classification: C08G

Abstract:
1. 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, in the presence of c) blowing agents, wherein the compounds having at least two hydrogen atoms which are reactive toward isocyanate groups b comprise b1) from 70 to 10 parts by weight of at least one polyether alcohol consisting exclusively of polyoxypropylene units or polyoxypropylene units and not more than 20% by weight, based on the total weight of the alkylene oxides used, of polyoxyethylene units in the polyether chain and having a nominal functionality of from 3 to 6 and a hydroxyl number in the range from 100 to 300 mg KOH/g, b2) from 10 to 70 parts by weight of at least one polyetherol consisting exclusively of polyoxypropylene units or polyoxypropylene units and not more than 20% by weight, based on the total amount of alkylene oxides used, of polyoxyethylene units in the polyether chain and having a nominal functionality of 2 and a hydroxyl number in the range from 50 to 240 mg KOH/g, b3) from 10 to 30 parts by weight of at least one polyether alcohol consisting exclusively of ethylene oxide units or ethylene oxide units and not more than 20% by weight, based on the total amount of alkylene oxides used, of polyoxypropylene units in the polyether chain and having a nominal functionality of from 2 to 3 and a hydroxyl number in the range from 50 to 550 mg KOH/g, and b4) from 0 to 20 parts by weight of at least one graft polyetherol which can be prepared by in-situ polymerization of olefinically unsaturated monomers in a polyether alcohol consisting of polyoxypropylene units or polyoxypropylene units and not more than 50% by weight, based on the total amount of alkylene oxides used, of polyoxyethylene units in the polyether chain and having a nominal functionality of from 2 to 3 and a hydroxyl number in the range from 20 to 40 mg KOH/g wherein pbw is based on 100 pbw of component b).