PROCESS FOR PREPARING FOAM MATERIALS RESISTANT TO PRESSURE AND HEAT FROM A MIXTURE OF A BITUMINOUS MASS WITH RESINS

1277136 Foamed bituminous/novolak compositions RUTGERSWERKE AG 31 Dec 1969 63613/69 Headings C3C C3N C3P and C3R A foamed material is made by adding at 150- 210‹ C. to a fluid mixture of a bituminous material and a novolak containing no free acid, a cross-linking agent for the novolak and a blowing agent which decomposes at 150-210‹ C., the mixture having a viscosity of 50-5000 cp. The novolak may be derived from phenol, a cresol or a xylenol. The bituminous material may be natural asphalt, petroleum bitumen, coal tar, lignite tar, wood tar, coal tar pitch or wood tar pitch. Tar bases may be added to the mixture of bituminous material and novolak before addition of the cross-linking and blowing agent, which may be one material, e.g. hexamethylenetetramine and the mixture may also contain polyethylene, polystyrene, polyvinyl chloride, or carbon black.