abstract |
A breathable or air-permeable, open cell, flexible urethane polymer suitable for use in cushions is formed from a foam-forming composition containing from about 0.5 to 2.0 parts by weight of butyl oleate, based upon 100 parts by weight polyol, under controlled pressure conditions maintained at or, preferably, below atmospheric pressure. The pressure during foaming is maintained in the range of about 0.5 to 1.0 bar, preferably 0.5 to 0.9 bar. Resultant air permeability is unexpectedly significantly increased over urethane polymers of equivalent composition. Other polymer properties are enhanced. |