| 摘要 |
Nickel acetyl acetonate catalysts used in the manufacture of polyurethanes and particularly polyurathane foam, is replaced with a more environmentally friendly organo-metallic catalyst, specifically other metal acetyl acetonates such as iron or copper. In accordance with an important feature of this invention, in addition to the metal acetyl acetonate, the catalyst system also includes acetyl acetone. The acetyl acetone acts as a delay mechanism to delay the catalytic action of the metal acetyl acetonate which is normally highly catalytic at relatively low temperatures. It will be appreciated that high catalytic activity at relatively low temperature will lead to deleterious premature cure. By adding acetyl acetone into the catalyst system, the acetyl acetone acts to delay and/or slow the catalytic action of the metal acetyl acetonate until the polyurethane is heated at which point the acetyl acetone is driven off and the metal acetyl acetonate then provides a relatively fast cure at the elevated temperature. |
