Patent ID: 6784218
Filing Date: 2004-08-31
Classification: B29C,C08G,C08J

Abstract:
A method of forming high resilience slabstock polyurethane foam having random cell structures, said method comprising the steps of:reacting an isocyanate-reactive component and an isocyanate component to form a polyurethane foam; wherein the isocyanate component is substantially free of toluene diisocyanate and comprises diphenylmethane-2,4â€²-diisocyanate present in an amount of from 15 parts by weight to 55 parts by weight based on 100 parts by weight of the isocyanate component; providing a first nucleation gas under low pressure; adding the first nucleation gas into at least on of the isocyanate-reactive component and the isocyanate component to produce a first cell structure in the polyurethane foam; and providing a second nucleation gas under low pressure, wherein the second nucleation gas is different than the first nucleation gas; and adding the second nucleation gas into at least one of the isocyanate-reactive component and the isocyanate component in a ratio of from 1:1 to 1:10 relative to the addition of the first nucleation gas to produce a second cell structure in the polyurethane foam different from the first cell structure.