PROCESS FOR THE PREPARATION OF BITUMEN / POLYMER COMPOSITIONS HAVING A REINFORCED MULTIGRADE CHARACTER AND APPLICATION OF THE COMPOSITIONS OBTAINED FOR THE PRODUCTION OF BITUMEN / POLYMER BINDERS FOR COATINGS

摘要

Bitumen/polymer compositions with a broadened plasticity range are produced by contacting a bitumen or bitumen mixture with a sulphur-cross-linkable elastomer and a sulphur-donating coupling agent, at 100-230 DEG C and under stirring conditions, to produce a cross-linked bitumen/polymer composition, then adding to the composition, maintained at 100-230 DEG C and under stirring conditions, an acidic additive selected from polyphosphoric acids, acids of formula R-(COO)t-SO3H, wherein t = 0 or 1 and R is a monovalent hydrocarbyl radical having up to 12 carbon atoms, and mixtures of both types of acid separately or jointly with sulphuric acid, and maintaining the resulting reaction medium at 100-230 DEG C and under stirring conditions for at least ten minutes. Said bitumen/polymer compositions may be used directly or in diluted form to produce bituminous binders for making road surfaces, coated materials or sealing coatings.