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 SAID COMPOSITIONS

摘要

A bitumen is mixed, between 100 .degree.C and 200 .degree.C with (i) a linea r sequenced styrene/conjugated diene copolymer A-B or A-B-A. A being a polymer sequence consisting of a polystyrene block alone or extended; on the B side, by a statistical styrene and conjugated diene copolymer, and B being a polymer sequence of the conjugated diene and (ii) a sulfur-donor coupling agent and the mixture obtained is maintained between 100 .degree.C and 230 .degree.C under stirring conditions during at least ten minutes. The se- quenced-copolymer has a molecular mass Mw between 120000 and 400000 and a styrene contents in the form of polystyren block comprised between 52 % and 14.7 % by weight of the copolymer. The resulting compositions are used for producing road surface coatings, sealing coats and covers.