| abstract |
A closed cell, rigid polymer foam which comprises the reaction product of a polyisocyanate and an isocyanate-reactive component in the presence of a catalyst and a hydrogen-containing blowing agent or a mixture of a hydrogen-containing blowing agent and at least one co-blowing agent wherein the isocyanate-reactive component comprises (a) a hydroxy terminated polyester having an equivalent weight greater than about 350, or (b) a mixture of the hydroxy terminated polyester with at least one other isocyanate-reactive compound. Foams prepared with the hydroxy terminated polyester have superior shrinkage resistance, strength and long-term insulating efficiency. |