Modified asphalt prepn. having improved penetration resistance

• Main Authors: JEAN MARIE MULLER, KAMAL BOUSSAD
• Format: Patent
• Language: English; Italian
• Published: 29.10.1991
• Edition: 5
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP

A process for modifying asphalt comprises mixing with asphalt, either as such or in aq. bituminous emulsion, 2.5-7.5 wt.% of a medium viscosity ethylene vinyl acetate (VA) polymer (I) having a melt index of 700-10,000 and contg. 5-40 wt.% pref. 11-40 wt.% of vinyl acetate. (I) has 0-10 alkyl-branches/1,000 backbone C atoms. The asphalt has a ring and ball softening point of more than 70 deg.C. (I) pref. contains 11-20 wt.% of vinyl acetate and is prepd. using a non-incorporating modifier. (I) has a density of more than 0.935 g/ml; a tensile strength at break of more than 5 MPa; a 1% secant modulus of more than 90 MPa; and/or Shore A hardness of more than 90.