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US-12623964-B2 - System and method for modifying and enhancing tire rubber bitumen

US12623964B2US 12623964 B2US12623964 B2US 12623964B2US-12623964-B2

Abstract

A method and system for generating a modified and enhanced dissolved tire rubber bitumen compound are described. The method includes receiving an rapid digestion process (“RDP”) compound, a bitumen compound, and a sulfur cross-linking agent. First heating the RDP compound, the bitumen compound, and the sulfur cross-linking agent to 320° F. to 420° F. with mixing for 3 to 5 hours. The method then proceeds to add SBC to the RDP compound, the bitumen compound, and the sulfur cross-linking agent. The RDP compound, the bitumen compound, the sulfur cross-linking agent, and the SBC are second heated to 320° F. to 420° F. with mixing for 15 minutes to 120 minutes.

Inventors

  • Joseph Randall Bruns
  • Hashem Hashemi

Assignees

  • ASPHALT SCIENCES LLC

Dates

Publication Date
20260512
Application Date
20221003

Claims (11)

  1. 1 . A method for generating a modified and enhanced dissolved tire rubber bitumen compound comprising: receiving a rapid digestion process (RDP) compound, wherein the RDP compound is selected from the list consisting of an unmodified RDP compound, a modified RDP compound, an enhanced RDP compound, and a modified enhanced RDP compound; receiving a bitumen compound; receiving a sulfur cross-linking agent; first heating the RDP compound, the bitumen compound, and the sulfur cross-linking agent to 320° F. to 420° F. with mixing for 3 to 5 hours; adding a Styrenic Block Copolymer (SBC) to the RDP compound, the bitumen compound, and the sulfur cross-linking agent; and second heating the RDP compound, the bitumen compound, the sulfur cross-linking agent, and the SBC to 320° F. to 420° F. with mixing for 15 minutes to 120 minutes to generate the modified and enhanced dissolved tire rubber bitumen compound.
  2. 2 . The method of claim 1 further comprising curing the modified and enhanced tire rubber bitumen compound with mixing for 12 hours to 48 hours.
  3. 3 . The method of claim 1 further comprising curing the modified and enhanced tire rubber bitumen compound with mixing for 20 hours.
  4. 4 . The method of claim 1 wherein the RDP compound has a penetration of 40 dmm to 60 dmm and a viscosity between 1000 cP and 4000 cP at 275° F.
  5. 5 . The method of claim 1 wherein the modified and enhanced tire rubber bitumen compound comprises 0.5% to 0.05% sulfur cross-linking agent.
  6. 6 . The method of claim 1 wherein the RDP compound, the bitumen compound, and the sulfur cross-linking agent are first heated to 380° F. with mixing for 4 hours.
  7. 7 . The method of claim 1 wherein the RDP compound, the bitumen compound, the sulfur cross-linking agent, and the SBC are second heated to 380° F. with mixing for 60 minutes.
  8. 8 . The method of claim 1 wherein the RDP compound, the bitumen compound, the sulfur cross-linking agent, and the SBC are second heated to 380° F. with mixing for 30 minutes.
  9. 9 . The method of claim 1 wherein the SBC includes Styrene-Butadiene-Styrene (SBS); and wherein the modified and enhanced tire rubber bitumen compound comprises 2.5% to 3.5% SBS.
  10. 10 . The method of claim 1 further comprising receiving a process oil.
  11. 11 . The method of claim 1 wherein the RDP compound includes 40% to 50% tire rubber.

Description

CROSS REFERENCE This patent application is a continuation-in-part of utility patent application Ser. No. 17/086,948, filed on Nov. 2, 2020, entitled SYSTEM AND METHOD FOR GENERATING TIRE RUBBER ASPHALT, which is a continuation of utility patent application Ser. No. 16/255,804, filed on Jan. 23, 2019 (now U.S. Pat. No. 10,843,966), entitled SYSTEM AND METHOD FOR GENERATING TIRE RUBBER ASPHALT, which claims the benefit of provisional patent application 62/661,609 entitled SYSTEM AND METHOD OF DISSOLVING TIRE RUBBER filed on Apr. 23, 2018 and is a continuation-in-part of utility patent application Ser. No. 15/283,82, filed Oct. 3, 2016 (now U.S. Pat. No. 10,214,617), entitled DISSOLVING TIRE RUBBER, which claims the benefit of provisional patent application No. 62/236,861, entitled DISSOLVING TIRE RUBBER filed on Oct. 3, 2015; all of which patent applications are incorporated by reference in this patent application. FIELD This invention relates to a composition, system and method for generating tire rubber bitumen. More specifically, the invention relates to a composition, systems and methods for dissolving tire rubber in bitumen or oil by heating the mixture. BACKGROUND Bitumens have been modified with rubber and elastomers to improve the properties of the resulting composition. For example, in Trumbore, U.S. Pat. No. 5,342,866, teaches an elastomeric-bitumen composition with improved low temperature performance and reduced resistance to flow at high temperatures. The Trumbore asphalt incorporates SBS and SIS block copolymers as the elastomeric compounds but does not phase separate and is compatible to production at high temperatures up to 475° F. (246° C.). While Nielsen, U.S. Pat. No. 4,068,023, teaches one of the earliest examples showing the incorporation of reclaimed rubber into asphalt for paving using elevated temperatures up to 450° F. (232° C.) with an admixture of aromatic oils. Each year the U.S. generates approximately 290 million scrap tires. About 12 million scrap tires are converted into ground tire rubber (“GTR”) or crumb rubber for modifying asphalt cements. Asphalt bitumen is a mixture of relatively high molecular weight compounds that do not distill off of petroleum in a refinery and include practically no polymers. In contrast, the major component of tire rubbers are cross-linked polymers. The utilization of scrap tire rubber in asphalt bitumen started in the mid-1960's when GTR was placed in asphalt bitumen surface treatments, such as chip seal applications. Martin, EP1877493, teaches a modified asphalt binder composition that includes about 40% by weight to about 98.9% by weight asphalt binder material, about 0.5% by weight to about 25% by weight crumb rubber, about 0.5% by weight to about 30% by weight of at least one synthetic polymer, and about 0.05% by weight to about 5% by weight of at least one acid. Martin also teaches a method for making a modified asphalt binder composition that includes providing neat asphalt, heating the neat asphalt to a temperature of between about 120° C. (248° F.) and about 200° C. (392° F.), adding modifying ingredients to the neat asphalt sequentially with mixing for period of between about 5 minutes and about 10 hours each, and agitating the with a low shear mixer or a high shear mixer for an additional period of between about 5 minutes and about 48 hours. Davis, U.S. Pat. No. 10,457,602, teaches asphalt formulations and methods of preparation suitable for roofing products that incorporate elastomers, post-consumer recycled olefinic polymers, and 10-80 mesh GTR. However, the inclusion of olefinic polymers, and especially polypropylene, disadvantageously decreases the impact resistance performance of asphalt shingle roof coatings. In all the disclosed formulations Davis limits the incorporation of GTR to 20% or less by weight and the incorporation of polymer elastomers to 18% or less by weight. Further, Davis limits the disclosed methods of preparation to mixing temperatures below 425° F. (218° C.). In terms of environmental concerns, the disposal of scrap tires is a major waste management issue. While these environmental concerns are important, there are various challenges associated with using GTR and other forms of scrap tire rubber. An initial challenge encountered with the use of GTR, or crumb rubber is their respective production. Both crumb rubber and GTR, such as ASTM Standards D5603 and 5644, are commonly prepared by removing steel belts, bead wire, and various incorporated fabric plies from scrap tires. Entire processing facilities are required for removal of steel belts, bead wire and other byproducts incorporated into the scrap tires. For another example, with respect to hot applied chip seal, the inconsistent dissolution of GTR and other forms of scrap tire rubber in asphalt bitumen can result in blockages to hot asphalt spray systems that apply the GTR/asphalt mixture. With respect to asphalt emulsions, the inconsistent dissolution of tire