| 摘要 |
<p>This invention provides a process for preparing a polyolefin resin foam, comprising the step of extruding to a low-pressure zone a melt of polyolefin resin containing a volatile blowing agent uniformly dispersed therein, the process being characterized in that the volatile blowing agent is a mixture of 5 to 95% by weight of 1,1,1,3,3-pentafluoropropane and 95 to 5% by weight of a low-boiling aliphatic hydrocarbon having a boiling point of 15 DEG C or lower. According to the invention, there is obtainable a foam of polyolefin resin which is excellent in heat insulating property, dimensional stability and the like and which can retain them for a long term, using a blowing agent which is free of ozone-depleting risks, unlikely to adversely affect global warming, nonflammable and highly compatible with raw materials for foams. <IMAGE></p> |
