Process for the preparation of bitumen-polymer compositions, application of the compositions obtained to the production of coatings and polymer master solution for obtaining the same compositions

摘要

A process is provided for the preparation of a bitumen-polymer composition which comprises (a) producing at a temperature of between 100 DEG C. and 230 DEG C., a mixture of (i) a bitumen; (ii) a linear block copolymer of styrene and a conjugated diene, the block copolymer being used in a quantity of from 0.5% to 25% by weight of bitumen and having a weight-average molecular weight of between 170,00 and 250,000 and a structure of A-B with A denoting a polymer block consisting of a polystyrene block which may be extended on the B side by a random copolymer of styrene and of the conjugated. diene and B denoting a polymer block consisting of conjugated diene units, and (iii) a coupling agent containing at least one sulphur-donor compound and used in an amount to provide a quantity of sulphur representing, by weight, 0.1% to 10% of the weight of the liner block copolymer of styrene and conjugated diene; and (b) keeping the mixture thus produced at a temperature of between 100 DEG C. and 230 DEG C. and with stirring, for a period of at least ten minutes.