| 摘要 |
PURPOSE:To obtain the title foam having a good compatibility with a halohydrocarbon blowing agent and excellent resistance to flame and smoking, by reacting an excess organic polyisocyanate with a specified mixed polyol in the presence of a blowing agent. CONSTITUTION:In the reaction of an excess organic polyisocyanate (e.g., diphenylmethane diisocyanate) with a polyol in the presence of a blowing agent and, optionally, a trimerization catalyst, said polyol comprises a mixture of at least 5%, based on the total polyol, novolac phenolic resin polyol (A) [e.g., an adduct of (pentafunctional) novolac phenolic resin with propylene oxide], at least 5%, based on the total polyol, polyester polyol (B) (e.g., a reaction product of phthalic anhydride with diethylene glycol) and a polyether polyol (C) (e.g., an adduct of glycerol with propylene oxide). The title foam having a good compatibility with a halohydrocarbon blowing agent, a low calorific value of combustion and excellent resistance to flame and smoking can be obtained.
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