| 摘要 |
PURPOSE:To produce the subject urethane foam having closed cells and excellent in heat insulating without high heat generation and without involving much danger by using a polyol, a polyisocyanate and formic acid as an expanding agent. CONSTITUTION:An objective foam is obtained from a polyol (e.g. polyether polyol), a polyisocyanate (e.g. hexamethylene diisocyanate) and formic acid as an expanding agent. In addition, the amount of formic acid used is 1.0-20 pts.wt. based on 100 pts.wt. polyol. |
