Abstract: Asphalt and elastomeric polymer compositions crosslinked with mixed polythiomorpholines or at least one alkyl polysulfide can give polymer modified asphalts (PMAs) with improved properties and/or reduced H2S evolution. When at least one alkyl polysulfide is used to completely or partially replace conventional crosslinkers such as S or MBT, mercaptobenzimidazole (MBI) may be optionally used as a co-crosslinker. The use of mixed polythiomorpholines as crosslinkers provide PMAs with better low temperature profiles (BBR m-values). The use of at least one alkyl polysulfide crosslinker gives PMAs with improved PAV-aged DSR results, and reduced H2S evolution. The use of at least one alkyl polysulfide crosslinker together with MBI may give PMAs with improved PAV DSR Fail Temperatures.

Abstract: An asphalt material having improved paving characteristics and processes for its preparation. An asphalt base material is heated in a mixing chamber to a temperature sufficient to melt the asphalt so that it can be stirred. A water-insoluble heavy metal soap is incorporated into the chamber in an amount effective to reduce the PAV-DSR temperature of the asphalt base material by an incremental amount of at least 1° C. Thereafter, the asphalt material is recovered from the mixing chamber to provide an asphalt product containing the heavy metal soap which exhibits a PAV-DSR temperature which is less than the PAV-DSR temperature for the corresponding base material without the addition of the heavy metal soap. The water-insoluble soap is a C14-C18 heavy metal soap such as a C16-C18 zinc- or calcium-based soap including zinc stearate, zinc oleate and zinc palmitate. The heavy metal soap is added to the mixing chamber in an amount within the range of 0.05-3.0 wt.

Abstract: An asphalt/aggregate composition having enhanced adhesion characteristics and its preparation. An asphalt base material is heated to a molten state in order to permit mixing of the asphalt with added components. A heavy metal soap is incorporated into the asphalt base material to enhance the adhesion of the asphalt base material with an aggregate component which is mixed with the asphalt base material to provide an asphalt/aggregate blend. The asphalt and aggregate can be blended together in a mixing chamber to provide a fluid asphalt/aggregate concrete which is then dispensed on a substrate surface or the asphalt base material and aggregate components can be separately applied to the substrate surface to provide the ultimate asphalt/aggregate concrete. The heavy metal soap is a C14-C18 heavy metal soap such as zinc stearate. Zinc oxide may also be added to the asphalt base material in an amount which is less than the amount of zinc stearate.

Abstract: In methods of preparing asphalt and elastomeric polymer compositions, it has been discovered that for a given crosslinker or vulcanizing agent there is an optimum crosslinking temperature to give a composition that has top and bottom softening points that are close. That is, rubber/asphalt compatibility is improved, where the crosslinking is performed within the optimum temperature range.

Abstract: Asphalt and polymer mixtures treated with an inorganic acid and cross-linked with sulfur and/or other crosslinkers or accelerators gives a polymer modified asphalt with improved high temperature properties. The acid should be added to the asphalt before the crosslinker.

Abstract: In methods of preparing asphalt and elastomeric polymer compositions, it has been discovered that for a given crosslinker or vulcanizing agent there is an optimum crosslinking temperature to give a composition that has top and bottom softening points that are close. That is, rubber/asphalt compatibility is improved, where the crosslinking is performed within the optimum temperature range.

Abstract: The present invention provides a method for preparing an asphalt and thermoplastic elastomer composition. The process comprises heating an asphalt cut in a stirred tank to a temperature sufficient to allow the stirring of the asphalt in the tank. A thermoplastic elastomer or rubber is added to the asphalt while continuing to stir the asphalt. The mixture is stirred at a speed and for a period of time sufficient to increase the distribution of the elastomer into the asphalt. The stirring speed is reduced and the temperature is increased to add crosslinking agents to the tank. Stirring is continued for a period of time sufficient to improve the distribution of the crosslinking agent dispersion in the asphalt. Crosslinking agents include compositions of mercaptobenzothiazole, zinc oxide and elemental sulfur; compositions of mercaptobenzothiazole, zinc oxide, and mixed polythiomorpholine; and compositions of zinc 2-mercaptobenzothiazole and dithiodimorpholine.

Abstract: It has been discovered that divalent metal oxides other than zinc oxide (ZnO) perform equivalently as activators in preparing asphalt polymer compositions. Typically, the crosslinker in these compositions is sulfur. Divalent metal oxides such as cupric oxide (CuO), magnesium oxide (MgO), and calcium oxide (CaO) provide alternative activators to give versatility to designing asphalt polymer compositions. In addition, some of these alternative divalent metal oxides are less expensive than the traditionally used ZnO.

Abstract: In methods of preparing asphalt and elastomeric polymer compositions crosslinked with phenol aldehyde resins and sulfur, such as polymer modified asphalt (PMA), it has been discovered that the MP1 compatibility may be improved by adding certain ionic metal salts. Suitable ionic metal salts include, but are not necessarily limited to, zinc oxide, cadmium oxide, and the like. Acceptable elastomeric polymers include, but are not necessarily limited to, styrene-butadiene copolymers. Additional sulfur-containing crosslinkers may also be used.

Abstract: An asphalt/aggregate composition having enhanced adhesion characteristics and its preparation. An asphalt base material is heated to a molten state in order to permit mixing of the asphalt with added components. A heavy metal soap is incorporated into the asphalt base material to enhance the adhesion of the asphalt base material with an aggregate component which is mixed with the asphalt base material to provide an asphalt/aggregate blend. The asphalt and aggregate can be blended together in a mixing chamber to provide a fluid asphalt/aggregate concrete which is then dispensed on a substrate surface or the asphalt base material and aggregate components can be separately applied to the substrate surface to provide the ultimate asphalt/aggregate concrete. The heavy metal soap is a C14-C18 heavy metal soap such as zinc stearate. Zinc oxide may also be added to the asphalt base material in an amount which is less than the amount of zinc stearate.

Abstract: An asphalt material having improved paving characteristics and processes for its preparation. An asphalt base material is heated in a mixing chamber to a temperature sufficient to melt the asphalt so that it can be stirred. A water-insoluble heavy metal soap is incorporated into the chamber in an amount effective to reduce the PAV-DSR temperature of the asphalt base material by an incremental amount of at least 1° C. Thereafter, the asphalt material is recovered from the mixing chamber to provide an asphalt product containing the heavy metal soap which exhibits a PAV-DSR temperature which is less than the PAV-DSR temperature for the corresponding base material without the addition of the heavy metal soap. The water-insoluble soap is a C14-C18 heavy metal soap such as a C16-C18 zinc- or calcium-based soap including zinc stearate, zinc oleate and zinc palmitate. The heavy metal soap is added to the mixing chamber in an amount within the range of 0.05-3.0 wt.

Abstract: Asphalt and elastomeric polymer compositions crosslinked with mixed polythiomorpholines or at least one alkyl polysulfide can give polymer modified asphalts (PMAs) with improved properties and/or reduced H2S evolution. When at least one alkyl polysulfide is used to completely or partially replace conventional crosslinkers such as S or MBT, mercaptobenzimidazole (MBI) may be optionally used as a co-crosslinker. The use of mixed polythiomorpholines as crosslinkers provide PMAs with better low temperature profiles (BBR m-values). The use of at least one alkyl polysulfide crosslinker gives PMAs with improved PAV-aged DSR results, and reduced H2S evolution. The use of at least one alkyl polysulfide crosslinker together with MBI may give PMAs with improved PAV DSR Fail Temperatures.

Abstract: Methods of modifying crude fractions are described herein. The methods generally include blending a crude fraction with an emissions reducing additive to form a modified crude fraction, wherein the modified crude fraction exhibits reduced sulfur emissions. The emissions reducing additive generally includes a dispersion of a metal oxide.

Abstract: Asphalt and polymer mixtures treated with an inorganic acid and crosslinked with sulfur and/or other crosslinkers or accelerators gives a polymer modified asphalt with improved high temperature properties. The acid should be added to the asphalt before the crosslinker.

Abstract: Asphalt compositions and methods of forming such are described herein. The asphalt compositions and methods of forming such are generally adapted to enable open air processing while producing asphalt compositions that exhibit properties capable of meeting SUPERPAVE™ specifications.

Abstract: The present invention provides a dispersing agent that facilitates the delivery of a cross-linking agent to polymer modified asphalt. The present invention further includes a composition comprising a liquid hydrocarbon, the dispersant and cross-linking agent, and methods of preparing the composition and of preparing cross-linked polymer modified asphalt composition.

Abstract: In methods of preparing asphalt including asphalt/elastomeric polymer compositions, it has been discovered that the emission or evolution of H2S can be reduced by adding certain H2S scavengers to the asphalt mixture, but that not every known H2S scavenger can be effective in this method. Particularly helpful H2S scavengers include inorganic metal salts. Suitable inorganic or organic metal salt H2S scavengers include, but are not necessarily limited to those where the metal of the salt is zinc, cadmium, mercury, copper, silver, nickel, platinum, iron, or magnesium, and mixtures of these salts.

Abstract: It has been discovered that a synthetic flux oil can contain and deliver asphaltites, such as gilsonite, more easily and readily to an asphalt to improve its properties. The synthetic flux oil includes the asphaltite and a carrier oil. Depending on the nature of the carrier oil, the synthetic flux oil may or may not need to be heated during mixing and incorporation into the asphalt.

Abstract: In methods of preparing asphalt and elastomeric polymer compositions such as polymer modified asphalt (PMA), it has been discovered that the compatibility can be improved by adding excess amounts of certain organic and inorganic metal salts beyond the proportions normally used. Suitable metal salts may be metal oxides that include, but are not necessarily limited to, zinc oxide, calcium oxide, and the like. The method of the invention also permits asphalt modified with other polymers such as ground tire rubber (GTR) to have improved compatibility. Additionally, the use of excess amounts of these metal salts helps control gel formation.

Abstract: The present invention provides a method for preparing an asphalt and thermoplastic elastomer composition. The process comprises heating an asphalt cut in a stirred tank to a temperature sufficient to allow the stirring of the asphalt in the tank. A thermoplastic elastomer or rubber is added to the asphalt while continuing to stir the asphalt. The mixture is stirred at a speed and for a period of time sufficient to increase the distribution of the elastomer into the asphalt. The stirring speed is reduced and the temperature is increased to add crosslinking agents to the tank. Stirring is continued for a period of time sufficient to improve the distribution of the crosslinking agent dispersion in the asphalt. Crosslinking agents include compositions of mercaptobenzothiazole, zinc oxide and elemental sulfur; compositions of mercaptobenzothiazole, zinc oxide, and mixed polythiomorpholine; and compositions of zinc 2-mercaptobenzothiazole and dithiodimorpholine.