| 摘要 |
PROBLEM TO BE SOLVED: To achieve an excellent moldability and a reduced density by using only MDI (methylene diisocyanate) as a polyisocyanate. SOLUTION: A masking agent is added to delay the initiation time of the crosslinking reaction. Since the initiation time of the crosslinking reaction is delayed by the masking agent, even when an MDI-type polyisocyanate is used, moldability is improved, and a reduced density is achieved due to the earlier progress of foaming reaction than that of crosslinking reaction. Use of 2-ethylhexanoic acid, bis(2-ethylhexyl)phosphate or the like as a masking agent allows the stable and long continuous operation of a high-pressure foaming machine, and prevents production troubles. COPYRIGHT: (C)2004,JPO |
