Foams from bituminous materials and novolak resins - for heat and sound insulating panels

摘要

Simultaneous foaming and hardening of bituminous material and novolak resin mixtures of 50-5,000 (pref. 100-1,000) cps. viscosity takes place at 150-210 degrees C (pref. 170-190 degrees C) in the absence of free acid by means of gases released during hardening or by addition of poreforming agents. Fillers (talcum, C black, asbestos) and/or modifiers such as polyethylene, PVC or polystyrene may be added to foamable compositions. The rigid foams produced are pref. additionally heated at 200-300 degrees C for several hrs. Products are resistant to heat and pressure.