| 摘要 |
Composition and process for production of rigid polyurethane and polyisocyanurate foam, and foam made from such composition and by such process. A composition for production of rigid polyurethane foam includes a) an organic compound containing at least 1.8 isocyanate-reactive groups per molecule; b) an organic polyisocyanate selected from the group consisting of: b1) alkyl or cycloalkyl polyisocyanates having at least two isocyanate groups, and in which the alkyl portion contains 2-6 carbon atoms; and b2) aromatic polyisocyanates containing at least 2 isocyanate groups, and at least two six-membered aromatic rings which are fused together or are joined by a carbon-carbon bond or are linked by a divalent linkage selected from the group consisting of alkylene groups of 1-6 carbon atoms, -O-, -CO-, -CO2-, -S-, and -SO2-; c) a catalytically effective amount of a catalyst capable of promoting formation of urethane bonds; d) an effective amount of a hydrochlorofluorocarbon blowing agent; and e) a foam stabilizing amount of a hydrolytically stable siloxane-oxyalkylene block copolymer surfactant containing capped hydroxyl groups in the oxyalkylene portion of the molecule. A process for making rigid polyurethane foam involves reacting and foaming such composition. |
