Patent attributes
The invention relates to a process for the preparation of mixtures containing bitumen and thermoplastic polymer at a high concentration, stable during storage, with particular characteristics of easy processability and movability which, once diluted, allow modified bitumens to be obtained with high performance characteristics. In particular, the process allows mixtures containing bitumen, thermoplastic polymer and wax, to be prepared, wherein the polymer is in a quantity varying from 5 to 30% by weight with respect to the weight of the mixture consisting of bitumen and polymer, and the wax is in a quantity varying from 4.7 to 16.7% by weight with respect to the weight of the total mixture, and comprises reacting a concentrated mixture (A), stable during storage, containing bitumen and from 5 to 30% by weight of thermoplastic polymer, with a hydrocarbon wax containing at least 40 carbon atoms and having a melting point of at least 700 C., in a weight ratio between the mixture (A) and wax ranging from 100:5 to 100:20, at a temperature ranging from 160 to 2000 C. and for a time ranging from 15 minutes to 7 hours, preferably from 15 to 120 minutes. An object of the invention also relates to new mixtures containing bitumen and thermoplastic polymer at a high concentration and mixtures obtainable from these by dilution.
