| 摘要 |
<p>A process for preparing low smoke-generating rigid foams with a polyisocyanate, a polyol, a blowing agent, and a catalyst and surfactant, which comprises using an aromatic polyisocyanate as a polyisocyanate in the range between 3 to 5 times to the total amount of the compounds having active hydrogen in chemical equivalent, a polyol having a hydroxyl value less than 200 and containing more than 10% of primary hydroxyl groups, and water as a blowing agent in the amount of 2 to 6 parts by weight against 100 parts of above polyol together with catalysts suitable for isocyanate trimerization as the main catalyst.</p> |
