Low density foams are prepared from an admixture which comprises an unsaturated polyester resin, a free radical initiator which initiator is activated at temperatures from about 100° to about 400°F, and a compound selected from a t-alkylhydrazinium salt or a carbonylhydrazine. The low density foams have uniform cell structure without cracks or voids and the process is efficient.
低密度泡沫由一种混合物制备而成,该混合物包括一种不饱和聚酯
树脂、一种自由基
引发剂(
引发剂在约 100° 至约 400°F 的温度下活化)和一种选自 t-烷基
肼盐或羰基
肼的化合物。低密度泡沫具有均匀的细胞结构,没有裂缝或空隙,工艺效率高。