soft, bojlig polyuretanskumplast framstelld of a polyether polyol terminated with propylene oxide

摘要

There is provided a process for the preparation of flexible polyurethane foams having excellent softness, the process comprising reacting in the presence of a foaming agent, (A) a polyhydroxyl containing polyether including from 75 to 90% by weight of ethylene oxide, the polyether having a functionality equal to or greater than 2, an equivalent weight of between 700 and 2,200 for each hydroxyl group, from 2 to 35 percent of primary hydroxyl groups, based on the total number of hydroxyl groups present and a ratio of weight percent value of ethylene oxide to the percent value of primary hydroxyl groups based on the total number of hydroxyl groups present of between 2.1 and 42.5, and (B) a polyisocyanate which is the product of the partial polymerization of toluene diisocyanate and a polyhydroxyl containing polyether which includes propylene oxide, wherein (A) and (B) are present respectively in amounts such that the molar ratio of isocyanate groups to hydroxyl groups, NCO/OH, is equal to or greater than 1, preferably from 1:1 to 1.15:1.