Formation of high-resilience urethane foam in the presence of morpholino-bearing polyalkylsiloxanes

A method for producing polyurethane foam which comprises reacting and foaming a reaction mixture containing (1) an organic polyol reactant comprising a polyether polyol having an average hydroxyl functionality from 2.1 to about 5 and an average primary hydroxyl content from about 35 to about 90 mole percent, based on the total moles of hydroxyl groups contained in the polyether polyol, (2) an organic polyisocyanate, (3) a tertiary-amine catalyst, (4) a blowing agent, and (5) a surfactant component comprising a morpholino-bearing polyalkylsiloxane consisting essentially of (a) monofunctional siloxy units, M.degree., the respective silicon atoms of which have two alkyls bonded thereto, the third silicon-bonded organic group being alkyl or Q where Q is morpholinoalkyl or morpholinoalkoxyalkyl, (b) an average of from about 0.5 to about 8 moles of difunctional dialkylsiloxy units for every two moles of M.degree., and (c) from zero up to an average of about 8 moles, for every two moles of M.degree., of difunctional monoalkylsiloxy units in which the second organic group bonded to silicon is Q where Q is as aforesaid, provided the said siloxanes contain an average of at least about 0.5 and no more than about 8 moles of said silicon-bonded Q groups for every two moles of M.degree.;

• and wherein the silicon-bonded alkyls have from one to four carbon atoms and the silicon-bonded Q groups have the formula, ##STR21## where p is 0 or 1, Q being morpholinoalkyl when p is 0 and morpholinoalkoxyalkyl when p is 1, R' is bi-valent alkylene having from two or four carbon atoms, R" is bivalent alkylene having from two to six carbon atoms, and R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are independently hydrogen or alkyl having from one to four carbon atoms.