Patent attributes
A cylindrical molding based on cellular polyurethane elastomers having a density according to DIN EN ISO 845 of from 300 to 900 kg/m3, a tensile strength according to DIN EN ISO 1798 of ≧2.0 N/mm2, an elongation at break according to DIN EN ISO 1798 of ≧200% and a tear propagation resistance according to DIN ISO 34-1 B (b), of ≧8 N/mm, wherein the cellular polyurethane elastomer is based on the reaction(i) of a prepolymer having isocyanate groups and based on(a) methylenediphenyl diisocyanate (MDI) and(b1) polyetherdiol having a molecular weight of from 1500 g/mol to 3000 g/mol and based on propylene oxide and/or ethylene oxide,with(ii) a crosslinking component comprising(b2) polyetheralcohol having a nominal functionality with respect to isocyanates of from 2 to 3 and a molecular weight of from 1500 g/mol to 6000 g/mol and based on propylene oxide and/or ethylene oxide,(c2) diol having a molecular weight of from 62 g/mol to 499 g/mol,(d) water and(e) catalysts,the polyols (b) present in the cylindrical molding and comprising (b1) and (b2) having an average polyol molar mass of less than 3900 g/mol.
