| 摘要 |
PURPOSE:To obtain a phenolic resin foam improved in corrosiveness, by mixing a resol phenolic resin with sodium sulfite, adding an acidic curing agent, and foaming and curing the mixture. CONSTITUTION:The desired phenolic resin foam is produced by adding 5- 40pts.wt. sodium sulfite to 100pts.wt. resol phenolic resin in the presence of an acidic curing agent, a blowing agent, and a surfactant, and foaming and curing the mixture. The sodium sulfite to be used above may be anhydrous or hydrated, and its form is preferably fine powder of about 40-100 mesh. It is preferably predispersed in the resol phenolic resin. |
