| abstract |
The present invention provides polyurethane and polyisocyanurate foams and methods for their preparation. More specifically, the present invention relates to closed cell, polyurethane and polyisocyanurate foams and methods for their manufacture. These foams are characterized by a fine uniform cell structure and little or no foam collapse. The foam is made using a polyol premix composition comprising a combination of a hydrohaloolefin blowing agent, a polyol, a silicone surfactant, and a precipitation resistant metal-based catalyst used alone or in combination with an amine catalyst. |