Abstract: It has been determined that a specific type of emulsion SBR can be used to modify asphalt cement to greatly enhance the resistance to shoving, rutting and low temperature cracking of asphalt concretes made therewith. It has further been determined that this emulsion SBR is compatible with virtually all types of asphalt and that modified asphalt cements made therewith have extremely high levels of force ductility, tenacity and toughness.

Abstract: This invention discloses a process for synthesizing a styrene-butadiene polymer, which is particularly useful for modifying asphalt to improve force ductility, elastic recovery, toughness and tenacity, by a process which comprises the steps of: (1) continuously charging 1,3-butadiene monomer, an organo lithium compound, a polar modifier and an organic solvent into a first polymerization zone, (2) allowing the 1,3-butadiene monomer to polymerize in said first polymerization zone to a conversion of at least about 90 percent to produce a living polymer solution which is comprised of said organic solvent and living polybutadiene chains having a number average molecular weight which is within the range of about 20,000 to about 60,000, (3) continuously withdrawing said living polymer solution from said first reaction zone, (4) continuously charging styrene monomer, divinyl benzene and the living polymer solution being withdrawn from the first polymerization zone into a second polymerization zone, (5) allowing the s

Abstract: It has been determined that rubbery terpolymers of a conjugated diolefin monomer, a vinyl aromatic monomer, and N-(isobutoxymethyl) acrylamide (IBMA) can be used to modify asphalt cement to greatly enhance the resistance to shoving, rutting, and low temperature cracking of asphalt concretes made therewith. These rubbery polymers have a Mooney viscosity which is within the range of about 35 to about 80. It has further been determined that these rubbery terpolymers are compatible with virtually all types of asphalt. It is particularly preferred for the rubbery polymers of this invention to also contain repeat units which are derived from hydroxypropyl methacrylate (HPMA).

Abstract: This invention discloses a process for synthesizing a styrene-butadiene polymer, which is particularly useful for modifying asphalt to improve force ductility, elastic recovery, toughness and tenacity, by a process which comprises the steps of: (1) continuously charging 1,3-butadiene monomer, an organo lithium compound, a polar modifier and an organic solvent into a first polymerization zone, (2) allowing the 1,3-butadiene monomer to polymerize in said first polymerization zone to a conversion of at least about 90 percent to produce a living polymer solution which is comprised of said organic solvent and living polybutadiene chains having a number average molecular weight which is within the range of about 20,000 to about 60,000, (3) continuously withdrawing said living polymer solution from said first reaction zone, (4) continuously charging styrene monomer, divinyl benzene and the living polymer solution being withdrawn from the first polymerization zone into a second polymerization zone, (5) allowing the s

Abstract: It has been determined that rubbery terpolymers of a conjugated diolefin monomer, a vinyl aromatic monomer, and N-(isobutoxymethyl) acrylamide (IBMA) can be used to modify asphalt cement to greatly enhance the resistance to shoving, rutting, and low temperature cracking of asphalt concretes made therewith. These rubbery polymers have a Mooney viscosity which is within the range of about 35 to about 80. It has further been determined that these rubbery terpolymers are compatible with virtually all types of asphalt. It is particularly preferred for the rubbery polymers of this invention to also contain repeat units which are derived from hydroxypropyl methacrylate (HPMA).