| abstract |
The invention provides a polyurethane and a polyisocyanurate foam and a preparation method thereof. More particularly, the present invention relates to closed cell polyurethane and polyisocyanurate foams and methods for their preparation. These foams are characterized by a fine uniform cell structure with little or no foam breakage. These foams are produced using a polyol premix composition comprising a combination of a hydrohalide olefin blowing agent, a polyol, a polyoxyn surfactant, and an amine catalyst, the amine touch The medium preferably has a Fluoride Generation Value of no more than about 1000 ppm. |