| 摘要 |
PURPOSE:To obtain a lightweight foamed polyurethane having a uniform density distribution by mixing an organic polyisocyanate with a specified active hydrogen component and a dehydrating agent, uniformly dispersing an inert gas in the mixture by agitation, and curing the mixture. CONSTITUTION:An organic polyisocyanate component (A) (e.g. 2,6-tolylene diisocyanate) is mixed with an active hydrogen component (B) comprising a high-molecular weight polyol (e.g. castor oil) and a low-molecular weight polyol (e.g. glycerol) and at least 1 pt.wt., per 100 pts.wt. component B, dehydrating agent (C) to produce a polyurethane foam-forming composition for mechanical froth foaming. An inert gas (e.g. carbon dioxide) is uniformly dispersed in this composition by mechanical agitation, and the obtained mixture is poured into a mold and cured to obtain a polyurethane foam molding. This molding is good in machinability, lowly warps after cutting, and can be desirably used as the material of a model or the like. |
