| 摘要 |
PURPOSE: To obtain a contraction, crack and void-free foam material capable of being mixed with a large amt. of a blowing agent by introducing a blowing agent lower than air in heat transfer properties into at least one flowable reactive component in a gaseous state. CONSTITUTION: A blowing agent having heat transfer properties lower than those of air is introduced into at least one flowable reactive component in a gaseous state. When the blowing agent is brought to a gaseous state to be finely dispersed in the reactive component within a gas blowing container by a hollow stirrer, an especially good result is obtained because surface exchange is large and gas is directly and rapidly absorbed by the reactive component to be dissolved. As the reactive component, general isocyanate, polyol and, if necessary, an additive are designated. As the blowing agent, from an aspect of the solubility to polyol, for example, monochlorodifluoromethane, monochlorodifluoroethane, octafluorocyclobutane, sulfur hexafluoride or the like are proper but monochlorodifluoromethane and sulfur hexafluoride are especially pref. |
