Abstract: Disclosed herein are linear block copolymers of formula A-B-A? or A-B*B-A?, wherein blocks A and A? are polystyrene blocks, block B is a poly(conjugated diene) block and * is a coupling agent having a vinyl content of from 10-60 mol %. The block copolymers have a polystyrene content of from 20-35 wt. %, relative to the overall weight of the block copolymer, and a molecular weight of from 200,000-300,000 g/mol. The block copolymers can be used with a wide variety of asphalt grades, and are valuable for producing homogeneous polymer modified asphalt compositions having an effective combination of performance properties, such as acceptable viscosity, good elastic response to an applied stress, and a low non-recoverable creep compliance. The combination of vinyl content and polymerization technology allows a high solution concentration during polymerization without excessive processing viscosity.

Abstract: Disclosed herein are linear block copolymers of formula A-B-A? or A-B*B-A?, wherein blocks A and A? are polystyrene blocks, block B is a poly(conjugated diene) block and * is a coupling agent having a vinyl content of from 10-60 mol %. The block copolymers have a polystyrene content of from 20-35 wt. %, relative to the overall weight of the block copolymer, and a molecular weight of from 200,000-300,000 g/mol. The block copolymers can be used with a wide variety of asphalt grades, and are valuable for producing homogeneous polymer modified asphalt compositions having an effective combination of performance properties, such as acceptable viscosity, good elastic response to an applied stress, and a low non-recoverable creep compliance. The combination of vinyl content and polymerization technology allows a high solution concentration during polymerization without excessive processing viscosity.

Abstract: The present invention is directed to a process for preparing a polymer modified bituminous binder composition in the substantial absence of crosslinking agents by heating a bitumen component in a stirred tank to a temperature from 185° C. to 221° C.; adding a block copolymer composition to the bitumen component while the bitumen component is being stirred to form a homogeneous mixture of the bitumen component and the block copolymer composition; and continuing to stir the homogeneous mixture while maintaining the temperature from 185° C. to 221° C. for a period of time from 4 hours to 30 hours thereby forming a cured polymer modified bituminous binder composition.

Abstract: A process for preparing compatible, selectively hydrogenated block copolymer-modified bituminous compositions comprising blowing a mixture of the block copolymer and bitumen with an oxidizing gas at temperatures of at least 375° C. for at least 75 minutes. The modifying polymer is a selectively hydrogenated styrenic block copolymer and no blowing catalyst is required. Stable bituminous compositions comprising 6 to 25 parts by weight of block copolymer per 100 parts of asphalt are also provided as well as their application as roofing shingles.

Abstract: Bituminous compositions are provided comprising a mixture of linear or radial block copolymers and diblock copolymers. The mass ratio of linear or radial block copolymer to diblock copolymer is in the range of about 5/1 to about 1/5 such that the resulting thermoplastic block copolymer composition mixes readily with bitumen but does not block before mixing. The non-blocking block copolymer composition has a bulk density in the range from about 20 lb/ft3 to about 30 lb/ft3 and includes from about 0.25% to about 10% by weight of a dusting agent. A process for producing the bituminous composition comprising high temperature, low shear mixing is also provided. The bituminous compositions herein provided are useful as road paving and asphaltic adhesive materials.