Process for the manufacture of low density, flexible polyurethane foams

Claim 1

A process for the manufacture of low density, flexible polyurethane foams which comprises reacting: (a) a polymer/polyol formed insitu in a polyether polyol having at least 85 percent primary hydroxyl groups, a nominal functionality of at least three, and an ethylene oxide content of from 8 to 30 percent of the polyether polyol; (b) 0.1 to 5 parts per hundred parts of polyol of a polyhydric material selected from the group consisting of glycerine, trimethylol propane, sorbitol, erythritol, sucrose, simple carbohydrates, and low molecular weight polyethylene oxide polyols which is reactive with isocyanate groups but not more reactive with an isocyanate group than are the primary hydroxyl groups on the polyether polyol (a), said polyhydric material also being sufficiently hydrophillic so as to be at least 40 weight percent soluble in 25° C. water; (c) water in an amount from 4.0 to 20 parts per hundred parts of polyol; (d) an organic polyisocyanate; and (e) 0.001 to 5 percent, based on the weight of (a), b, c and d, of a catalyst for the reaction of (a) and (d) in the presence of a foam stabilizer.