Burgess, Ryan and Wayne
Method for the preparation of bitumens modified by polymers
 A process for the preparation of bitumen-polymer compositions, characterized by the fact that the bitumens are modified by grafting of a dihalopolybutadiene polymer that serves as a receptive structure to block polymers and to elastomers co-vulcanizable with the grafted bitumen. The elastomers are selected from the group that includes linear polybutadiene-polystyrene block copolymers, a polystyrene-polybutadiene block copolymer, and a vulcanizable polynorbornene rubber. They are used as road and industrial bitumens. 
Elf Union
C C C
C08L C10C C08C
inventional inventional inventional
Fredj Paul
Fitoussi Maldonado