| abstract |
The present invention provides polyurethane and polyisocyanurate foams and methods for their preparation. More particularly, the present invention relates to open cell (open cell) polyurethane and polyisocyanurate foams and methods for their preparation. These foams are characterized by a fine and uniform cell (cell) structure with little or no foam collapse. This foam is produced with a polyol premix composition comprising a combination of a hydrohaloolefin blowing agent, a polyol, a silicone surfactant, and a sterically hindered amine catalyst. |