Polymer/polyol compositions made from preformed polymer/polyols, processes for making same and processes for making polyurethane products therefrom

In a process for producing a liquid polymer/polyol composition which is convertible by reaction with a polyisocyanate to a polyurethane product wherein the polyol of said composition is normally liquid at the temperature at which said composition is converted to said polyurethane product and said polymer is formed in situ in said polyol from one or more polymerizable ethylenically unsaturated monomers, the improvement utilizing first and second polyols and providing more stable dispersions of small particles of said polymer in said polyols, comprising, polymerizing one or more polymerizable ethylenically unsaturated monomers in the presence of a first free radical catalyst in said second polyol to form a preformed polymer/polyol having a viscosity of less than 40000 cps at 25.degree. C.;

• mixing a major amount of said first polyol having a number average molecular weight of at least about 76 with a minor amount of said preformed polymer/polyol to form a mixture thereof;
• and polymerizing one or more polymerizable ethylenically unsaturated monomers in the presence of a second free radical catalyst in said mixture to form said composition in which said polymer is formed in situ from both said portions of said monomer or monomers and is dispersed in said polyols and wherein each of said preformed polymer/polyol and said more stable dispersion have a greater dispersion stability than the polymer/polyol having the same chemical composition as that of said more stable dispersion and made in the same manner as said more stable dispersion but in the absence of said preformed polymer/polyol.