申请人:——
公开号:US20040082675A1
公开(公告)日:2004-04-29
Rigid foams having good insulation properties are made by reacting a polyisocyanate with an isocyanate-reactive material in the presence of a blowing agent mixture composed of from about 1 to 70% by weight of a low boiling hydrogen containing chlorofluorocarbon, such as chlorodifluoromethane (HCFC-22) and from 30 to 99% by weight of a C
2
-C
5
polyfluoroalkane, such as 1,1,1,3,3-pentafluoropropane (HFC-245fa).
具有良好隔热性能的硬质泡沫是由多异氰酸酯与异氰酸酯反应材料在发泡剂混合物的存在下发生反应而制成的,发泡剂混合物的重量百分比为 1%至 70%的低沸点含氢氯氟碳化合物,如氯二氟甲烷(HCFC-22)和 30%至 99%的碳氢化合物。
2
-C
5
多氟烷烃,如 1,1,1,3,3-五氟丙烷 (HFC-245fa)。