| 摘要 |
PURPOSE:To provide a process for producing a phenolic resin foam which is attracting attention as a construction material due to its flame retardancy and less-fuming properties, which process is free from a problem that a phenolic resin foam having all of lightweight properties, strength, and processability has been unable to be produced efficiently by any conventional method. CONSTITUTION:A phenol is reacted with formaldehyde or a derivative thereof in the presence of a basic catalyst to obtain a condensate. This condensate is neutralized by adding thereto a mixed acid containing phosphoric acid, thereby to obtain a resol resin. This resin is mixed with a foam stabilizer, a foaming agent, an inorganic filler, a hardener, etc., and the resulting foamable composition is foamed to obtain the objective phenolic resin foam. |
