| 摘要 |
This invention relates to a new process for the preparation of improved polymeric bitumens. The process is characterized by preparing a first composition by admixing a petroleum fraction (160 DEG -230 DEG C.), while stirring, at a temperature of from 80 DEG C. to 120 DEG C., with a copolymer made of styrenic blocks and dienic blocks such as a styrenebutadiene disequenced or multisequenced or statistical copolymer having a molecular weight varying between 30,000 and 300,000 and crystallized sulfur which is not chemically bound. When homogeneity is obtained, a portion of said first composition is admixed for at least 15 minutes at a temperature of from 130 DEG C. to 230 DEG C., with a conventional bitumen (penetration 20-220) to form a fluid polymeric bitumen. The fluid polymeric bitumen obtained by the process of the present invention is an excellent product characterized by superior properties and this product can be used in conventional spreading means when applying coatings onto roads. |
