PROCESS FOR THE PREPARATION OF STABLE MIXTURES OF BITUMEN AND POLYMER

摘要

Mixtures of bitumen and thermoplastic polymer stable to storage are prepared by a process comprising: (i) mixing a bituminous product having a content of total asphaltenes, resins, saturated and aromatic products which satisfies the condition that the I value is between 0.200 c and 0.270 in the expression: I c = (C7+C5+S)/(A+R) with a thermoplastic polymer, the reaction being carried out at a temperature of between 160.degree.C and 200.degree.C and for a time of between 15 and 120 minutes and (ii) diluting the bituminous composition obtained in (i) with a bitumen or bituminous component having an I c defined as specified above in (i) of between 0.270 and 0.700 in such a quantity that the final concentration of the polymer is between 2.5 and 15% by weight, and heating to a temperature of between 160.degree.C and 200.degree.C for a time of between 30 and 90 minutes.