| abstract |
Composition comprising the reaction product of a bitumen and an oil such as castor oil, and process for the preparation of such a composition. The reaction product is combined with a polyhydroxy compound and a polyisocyanate, and allowed to react in the presence of a blowing agent, such as water, to form a foam of polymeric material. A particularly suitable blowing agent, the use of which eliminates the need for a surfactant in the reaction mixture, consists of a mixture of dibutyl phthalate and ethanol. |