| abstract |
PCT No. PCT/FR96/01605 Sec. 371 Date Aug. 22, 1997 Sec. 102(e) Date Aug. 22, 1997 PCT Filed Oct. 15, 1996 PCT Pub. No. WO97/14753 PCT Pub. Date Apr. 24, 1997Bitumen/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 DEG -230 DEG C. and under stirring conditions, to produce a cross-linked bitumen/polymer composition, then adding to the composition, maintained at 100 DEG -232 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 DEG -230 DEG C. and under stirring conditions for at least ten minutes. The bitumen/polymer compositions may be used directly or in diluted form to produce bituminous binders for making road surfaces, coated materials or sealing coatings. |