| 摘要 |
<p>A method of making a foamed, polyester resin comprises mixing a liquid unsaturated polyester composition, with a liquid borohydride blowing agent which is a liquid borohydride complex, a borohydride complex in organic liquid medium or a borohydride salt dispersed in an organic liquid medium, which medium is at least substantially non-reactive with the borohydride salt. The resulting mixture is permitted to foam and gel under the initial influence of the blowing agent. In one embodiment the liquid unsaturated polyester includes a peroxide as a curing agent and an amine promoter is additionally admixed therewith. In this case a foamed, gelled and cured resin results. The borohydride complexes are usefully quaternary amine borohydrides.</p> |
