RECYCLED OIL AND RUBBER-MODIFIED ASPHALT AND METHOD OF USE

Abstract

A asphalt binder modifier or a stand-alone asphalt binder and the method of making the asphalt binder or binder modifier are disclosed. The asphalt modifier or binder consisting of treated re-refined engine oil bottoms/VTB's treated by injecting air into re-refining engine oil bottoms/VTB's at temperatures between 150° F. and 550° F. The re-refined engine oil can be processed with ground tire rubber. The binder modifier was blended with various paving and roofing asphalts to form performance-enhanced modified asphalt binders used in paving, roofing, and industrial products.

Claims

1. A modifier for asphalt comprising re-refined engine oil, ground tire rubber and at least one of a plastomer or an elastomer, wherein the re-refined engine oil and ground tire rubber are oxidized by heating the re-refined engine oil and ground tire rubber to a temperature of about 150° F. to about 550° F. or to 50° F. below the flash point of the re-refined engine oil and injecting air into the re-refined engine oil and ground tire rubber while mixing, wherein after oxidation the modifier has a softening point of at least 150° F. and penetration values that vary by 75 decimillimeters or less when measured at about 39° F. and about 115° F.

2. The modifier of claim 1, wherein the modifier is oxidized prior to the addition of the at least one of a plastomer or an elastomer.

3. The modifier of claim 1, wherein the at least one of a plastomer or elastomer is added prior to oxidation of the re-refined engine oil and ground tire rubber.

4. The modifier of claim 2, wherein the elastomer is selected from the group consisting of styrene-butadiene-styrene, styrene-isoprene-styrene, styrene-butadiene rubber, styrene-butadiene polymer, styrene-ethylene-butadiene-styrene, reactive polymers, ter-polymers, natural rubbers or combinations thereof.

5. The modifier of claim 3, wherein the elastomer is selected from the group consisting of styrene-butadiene-styrene, styrene-isoprene-styrene, styrene-butadiene rubber, styrene-butadiene polymer, styrene-ethylene-butadiene-styrene, reactive polymers, ter-polymers, natural rubbers or combinations thereof.

6. The asphalt modifier of claim 2, wherein the plastomer is selected from the group consisting of polyethylene, ethylene-vinyl-acetate, APO, amorphous polyolefin, or APP, or a combination thereof.

7. The asphalt modifier of claim 3, wherein the plastomer is selected from the group consisting of polyethylene, ethylene-vinyl-acetate, APO, amorphous polyolefin, or APP, or a combination thereof.

8. The asphalt modifier of claim 3, wherein the plastomer is polyethylene.

9. An asphalt modifier emulsion comprising re-refined engine oil, ground tire rubber, and water, wherein the re-refined engine oil and ground tire rubber are oxidized by heating the re-refined engine oil and ground tire rubber to a temperature of about 150° F. to about 550° F. or to 50° F. below the flash point of the re-refined engine oil and injecting air into the re-refined engine oil and ground tire rubber while mixing, wherein after oxidation the modifier has a softening point of at least 150° F. and penetration values that vary by 75 decimillimeters or less when measured at about 39° F. and about 115° F.

10. The asphalt modifier emulsion of claim 9, further comprising at least one of an elastomer or a plastomer.

11. The asphalt modifier emulsion of claim 10, wherein the elastomer is selected from the group consisting of styrene-butadiene-styrene, styrene-isoprene-styrene, styrene-butadiene rubber, styrene-butadiene polymer, styrene-ethylene-butadiene-styrene, reactive polymers, ter-polymers, natural rubbers or combinations thereof.

12. The asphalt modifier of claim 10, wherein the plastomer is selected from the group consisting of polyethylene, ethylene-vinyl-acetate, APO, amorphous polyolefin, or APP, or a combination thereof.

13. The asphalt modifier of claim 12, wherein the plastomer is polyethylene.

14. The asphalt modifier of claim 12, wherein the inert gas is nitrogen.

15. The asphalt modifier of claim 12, further comprising injecting air combined with the inert gas into the re-refined engine oil and ground tire rubber while mixing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] FIG. 1 is a flow diagram describing preparation of the RREO modifier and the more common possible uses in paving, roofing, and industrial products containing asphalt.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0033] For a fuller understanding of the invention, reference should be made to the following detailed description, taken in connection with the accompanying drawing.

[0034] As used herein, “about” means approximately or nearly and in the context of a numerical value or range set forth means±15% of the numerical.

[0035] As used herein, “substantially” means largely if not wholly that which is specified but so close that the difference is insignificant.

[0036] As used herein, “PG Rating” is defined as the average seven-day maximum and the single-day minimum pavement design temperature, wherein the maximum is determined 20 mm below the surface of the pavement and the minimum is determined at the surface of the pavement.

[0037] Processed re-refined engine oil (RREO) vacuum tower bottoms were treated and combined with GTR particles at elevated temperatures and mechanical mixing at either high or low shear, resulting in a stable homogeneous mixture that is resistant to settling, and which provides performance enhancing properties to the re-refined engine oil. Specifically, the admixture exhibits higher elastic modulus at high temperatures and improved low temperature properties. When the admixture of RREO and GTR is combined with asphalt, the performance properties of the asphalt are dramatically improved. The asphalt exhibits elastomeric properties: improved weathering, adhesion, viscosity, resistance to water, improved low temperature properties (Creep Stiffness and/or Flexibility), anti-aging properties, and improved adhesive properties. The degree of property improvement possible is dependent upon the composition and processing of the GTR-Re-refined Engine Oil mixture, the host asphalt and the means of combining the RREO-GTR admixture with asphalt.

[0038] GTR is processed to access the oils, uncross-linked polymer sites and carbon black contained in the material. Access to uncross-linked polymer sites requires minimizing particle size, i.e. maximizing access to any uncross-linked polymer sites. However, conventional GTR processing results in particles that either are suspended in a binder or settle out of the binder, and therefore fails to optimize the access to un-cross-linked polymer sites. Further, such processing fails to dissolve the GTR into a homogeneous mixture, which improves binder properties, such as binder stability over time.

[0039] The GTR-RREO admixture is a combination of ground tire rubber (GTR) and re-refined engine oils, RREO's, in various ratios processed in a mixing vessel employing paddle and/or high shear and/or circulation with or without the presence of incorporated air at temperatures from 150° F. to 550° F. with mixing/blending times of 30 minutes to 48 hours to produce a homogeneous mixture of finely dispersed GTR particles in the re-refined engine oil bottoms (VTB's). The processing procedures are summarized in a flow diagram seen in FIG. 1.

[0040] The admixture provides a means to use recycled products, RREO and GTR, in asphalt products to assist in satisfying various “green programs,” reducing carbon footprints, and achieving higher degrees of sustainability. Further, compositions of RREO and GTR disclosed herein may provide 60% to 80% of the elastomeric properties of traditional binder elastomer additives like styrene-butadiene-styrene, styrene-butadiene rubber, and styrene-butadiene polymer, but without the cost and in a more environmentally-friendly manner.

Example 1

[0041] Re-refined engine oil vacuum tower bottoms were collected from the re-refining of engine oil using a thin/wiped film evaporator, such as those provided by LUWA and Artisan Industries. Properties for the RREO before and after processing are provided in Table 4. It is noted that conventional distillation of oil is not a preferred method of re-refining for various reasons. The collected RREO was transferred to a mixing vessel or tank having a continuous circulation loop equipped with heating mechanisms utilizing hot oil or steam traced tubes, fire tubes, electric plates, or other methods of heating practiced in the industry. The tank was optionally equipped with internal and/or external circulation, internal mixing and/or external circulation through a high shear mill. The RREO was mixed while air was injected at 0.1-2 L/min./kg, and dispersed, into the liquid RREO at temperatures ranging from 150° F.-550° F., resulting in a product having a high viscosity, such as a shear susceptible homogeneous paste-like material analogous to grease. Re-refined engine oil oxidation levels are measured and controlled by altering the time, from 1 to 24 hours, temperature, and amount of air injected into the re-refined engine oil. Injected air is dispersed within the tank using sparger tubes, and impellers designed to generate fine bubbles in the processed liquid, i.e., RREO. To optimize oxidation time, air is injected as small bubbles. Additionally, use of long volatile stills can also increase control time. It is preferred that the RREO is oxidized at 1-3 L/min/kg of product. However, lower oxidation levels can be utilized, as well as higher oxidation levels. Of particular note, higher oxidation levels must be considered in light of increased effluent carry-over of oils, and a balancing of oxidation to oil carry-over must be considered. Such balancing is within the capability of one skilled in the art. Coalescence is minimized and dwell/contact time optimized as is known in the art. The consistency/viscosity of the final product is dependent on the RREO oxidation levels, and the degree of contact with air. Optionally, the RREO is heated to and maintained at a temperature of 300° F.-550° F.

[0042] An alternate method of introducing the air is the employment of a high shear mixer capable of creating a vortex. The vortex pulls air into the liquid mixture, enabling an oxidative reaction with reduced emissions. Industry standard mixers exhibiting suitable mechanics to create a vortex are: Cowles, Greerco, Silverson, Cady, and others.

[0043] The vessel, tanks and/or circulation loop may be equipped with high or low shear mixing, air injection, baffles and/or other mechanical means to facilitate the blending/mixing and reaction process.

[0044] The consistency of the RREO is adjusted by adjusting the parameters of temperature, air contact time, air dispersion, and air to RREO ratios.

[0045] When RREO and GTR are jointly processed, in addition to the aforementioned parameters, internal and external circulation optimally incorporating a shear mill or digestion system facilitates the GTR size reduction. Reduced particle sizes are achievable.

[0046] Examples 1-3 represent re-refined engine oils from three separate sources from different regions within the United States. Each was subjected to laboratory processing at 500±10° F. from 4.5 to 9.0 hours. The processing time represents the time required to achieve a targeted Softening Point in the range of approximately 210° F.-240° F. The process involved: internal high shear mixing by a Silverson laboratory mixer and simultaneous injection of air. A nitrogen blanket was injected on the surface of the mixing vessel to provide an inert atmosphere and therefore enhance the safety of the process.

[0047] Example 1 demonstrates the feasibility to alter and control the rheological profile and physical properties of the base re-refined engine oil by combining the RREO with air (oxygen). Testing of the resulting product showed significant increase in viscosity with consistent characteristics over a wide range of temperatures, as seen in Table 4. These properties are highly beneficial in paving, roofing, and industrial products. The properties facilitate processing, while reducing (based on use level) the thermal susceptibility, gaining more flexibility in cold temperatures and adding stiffness at high temperatures of the host product if used as an additive to neat, modified, or filled asphalts.

TABLE-US-00004 TABLE 4 Results of Oxidation of RREO from Supplier (located in the Midwest) ASTM Test Properties Method Results Comments Mixing Process Temperature, ° F. Probe 500 ± 10 PRI procedure, Silverson Time, hours To targeted 7 laboratory high shear mixer end point RREO Before Processing Flash Point, COC, ° F. D 92 510 Flash Points differences by Test Flash Point, PMCC, ° F. D 93 460 Method Composition, Asphaltenes D 4124 via 12.5 Typical composition of RREO Component Polar Iatroscan 25.5 based on types, grades and Fractions, % Aromatics proportions of in-feed engine oils Naphthene 0.0 Aromatics Saturates 62.0 Softening Point, ° F. D 36 <60 Approximately a high viscosity Penetration, dmm 39.2° F. D 5 <300 semi-solid After Processing Softening Point, ° F. D 36 212 Targeted SP meets shingle coating requirements Penetration, dmm 39.2° F. D 217 257 Exhibits a highly desired uniform 77° F. 282 consistency, which exhibits 115° F. 295 minimal change with temperature Solubility, TCE, % D 2042 100 Homogeneity, purity Rotational 10 rpm 14,750 Material exhibits shear Viscosity, 300° F., 50 rpm D 4402 4,050 susceptibility. Provides advantages cps 100 rpm 2,300 during subsequent processing Separation, Top ⅓ D 7173/D 36 197.6 Demonstrates homogeneity and 163° C., 48 hrs, Bottom ⅓ 195.8 stability SP, ° F. Difference, ° F. 1.8 DSR, G*/sinδ, 106° C. D 7175 1.550 Material classifies as a PG 112-XX kPa 100° C. 1.770 if used in paving 94° C. 2.000

[0048] In asphalt derived from refining crude oil, all four component fractions are present, Asphaltenes (A), Polar aromatics (PA), Naphthene aromatics (NA), and Saturates (S). When oxidized, the NA's converted to PA's and the PA's converted to A's, such that the resultant rheological profile reflects a stiffer material exhibiting a higher Softening Point (SP) accompanied by lower Penetrations. For example, a 200° F.-220° F. Softening Point would exhibit a 12-26 dmm Penetration at 25° C.; ≤8 dmm at 4° C., and ≤75 dmm at 46° C.

[0049] Without being bound to any specific theory, it is hypothesized the wear metals indigenous to RREO's are a prime contributor to the processed properties. Useful wear metals include zinc, copper, iron and molybdenum, and nickel. Some exemplary metals, and their respective amounts, are shown in Table 5.

TABLE-US-00005 TABLE 5 Listing of some common wear metals found in used engine oils. Name of study testing Amount of wear metals found in various used engine oils, mg/kg used engine oil zinc nickel copper chromium iron lead Rosado & Pichtel.sup.1 838.0 N/A N/A N/A N/A 110.0 Raymond, et al..sup.2 1500 N/A 17 21 260 7500 Cotton, et al..sup.3 2500 N/A 56 24 655 13885 Vazquez-Duhalt.sup.4 1100 1 28 10 N/A N/A ATSDR.sup.5 480 N/A N/A 6.5 N/A 240 N/A—data on specific wear metal not available .sup.1Dominguez-Rosado & Pichtel, Chemical characterization of fresh, used and weathered motor oil via GC/MS, NMR and FTIR techniques. Proc. Indiana Acad. Sci. 2003; 112(2): 109-116; .sup.2Raymond, et al., Oil degradation in soil. App. Envir. Microbiol. 1975; 31: 522-35; .sup.3Cotton, et al., Analysis of 30 used motor oils. Hydrocarb. Process. 1977; 131-140; .sup.4Vazquez-Duhalt, Environmental impact of used motor oil. Sci. Total Envir. 1989; 79: 1-23; .sup.5Agency for Toxic Substances and Disease Registery, Toxicological profile for used mineral-based crankcase oil. 1997; U.S. Dept Health Human Services, Public Health Service, Atlanta, GA.

[0050] The RREO exhibits a stiff paste-like consistency with minimal change in Penetration over a wide temperature range, from 39.2° F.-115° F.

Example 2

[0051] Re-refined engine oil was obtained from a supplier and RREO oxidation was performed using an internal high shear mixer for 1 to 7 hours, high shear mixing, and temperature of 500±10° F. Air was injected as described in Example 1, and an N.sub.2 blanket was used. The results are summarized in Table 6.

TABLE-US-00006 TABLE 6 Results of Oxidation of RREO from Supplier II (located in the Southeast). ASTM Test Properties Method Results Comments Mixing Process Temperature, ° F. Probe 500 ± 10 PRI procedure, Silverson laboratory Time, hours To targeted 4.5 high shear mixer end point RREO Before Processing Flash Point, COC, ° F. D 92 565 Flash Points differences by Test Flash Point, PMCC, ° F. D 93 470 Method Composition, Asphaltenes D 4124 via 2.6 Typical composition of RREO Component Polar Iatroscan 44.7 exemplifies differences from Fractions, % Aromatics different re-refiners Naphthene 0.0 Aromatics Saturates 52.7 Softening Point, ° F. D 36 — Essentially a high viscosity liquid; Penetration, dmm 39.2° F. D 5 — becomes a semi-solid like material DSR, G*/sinδ, kPa 4° C. D 7175 1.575 below 10° C. 10° C. 0.805 After Processing Softening Point, ° F. D 36 242 Targets a high SP, which may be letdown to desired elastic modulus Penetration, dmm 39.2° F. D 217 178 Exhibits a highly desired uniform 77° F. 224 consistency, which exhibits minimal 115° F. 245 change with temperature Solubility, TCE, % D 2042 99.3 Homogeneity, purity Rotational 10 rpm 21,900 Material is shear susceptible. Viscosity, 300° F., 50 rpm D 4402 4,740 Provides advantages in subsequent cps 100 rpm — processing Separation, 163° C., Top ⅓ D 7173/D 36 170 Exhibits less homogeneity and 48 hrs, SP, ° F. Bottom ⅓ 182 stability than Source 1 Difference, ° F. 12 DSR, G*/sinδ, kPa 106° C. D 7175 2.300 Material classifies as a PG 118-XX 100° C. 3.000 if used in paving 94° C. 3.700

[0052] The second source of RREO exhibits a composition with significantly less Asphaltenes and significantly more Polar Aromatics. This RREO, when processed the same as in Example 1, exhibited similar properties. The Softening Point was significantly increased with corresponding decreases in Penetration. The Penetration values were lower (stiffer) than the source of RREO in Example 1, and as a result, exhibited a 30° F. higher Softening Point after processing. The RREO of Example 2, achieved a 242° F. Softening Point in 4.5 hours vs. the 212° F. Softening Point compared to Example 1, which required 7 hours of processing. As such, Example 2 would have a PG classification of PG 118-XX.

Example 3

[0053] Re-refined engine oil from a third supplier was obtained and RREO oxidation was performed using an internal high shear mixer at a temperature of 500±10° F. with high shear mixing. The system was set to a final Softening Point of 200+° F., which is universal in asphalt roofing shingle markets. Air was injected as described in Example 1, and N.sub.2 blanket used. The results are summarized in Table 7.

TABLE-US-00007 TABLE 7 Results of Oxidation of RREO from Supplier III (located on the west coast). ASTM Test Properties Method Results Comments Mixing Process Temperature, ° F. Probe 500 ± 10 PRI procedure, Silverson laboratory Time, hours To targeted 9 high shear mixer end point RREO Before Processing Flash Point, COC, ° F. D 92 505 Flash Points differences by Test Flash Point, PMCC, ° F. D 93 475 Method Composition, Asphaltenes D 4124 via 8.5 Typical composition of RREO. Component Polar Iatroscan 28.2 Exemplifies differences by re- Fractions, % Aromatics refining source. Composition differs Naphthene 0.0 from those of Sources I and II. Aromatics Saturates 63.3 Softening Point, ° F. D 36 — Too fluid to test Penetration, dmm 39.2° F. D 5 — DSR, G*/sinδ, kPa 4° C. D 7175 — 10° C. — After Processing Softening Point, ° F. D 36 208 Targeted all market sectors Penetration, dmm 39.2° F. D 217 222 Exhibits a highly desired uniform 77° F. 264 consistency, which exhibits minimal 115° F. 280 change with temperature Solubility, TCE, % D 2042 93.9 Homogeneity, purity Rotational 10 rpm 17,800 Material is shear susceptible. Viscosity, 300° F., 50 rpm D 4402 4,400 Provides advantages during cps 100 rpm 2,450 subsequent processing. Separation, 163° C., Top ⅓ D 7173/D 36 204 Exhibits slightly less homogeneity 48 hrs, SP, ° F. Bottom ⅓ 208 and stability than Source I Difference, ° F. 4 DSR, G*/sinδ, kPa 106° C. D 7175 1.520 Material classifies as a PG 112-XX 100° C. 1.980 if used in paving 94° C. 2.400

[0054] The RREO from the third supplier source exhibited yet another composition which was more liquid at standard conditions and took longer to achieve the targeted Softening Point via the same process. Once the targeted Softening Point was achieved, the properties of the RREO exhibited the same benefits, namely high temperature stability with excellent low temperature properties, homogeneity, and only slight separation. Similar to Examples 1 and 2, Rotational Viscosities indicated a shear susceptible material.

[0055] Examples 4-8 illustrate the feasibility and some benefits when ground tire rubber (crumb rubber) is combined with the RREO and processed using the process described above, altering the temperature and times to adjust for the GTR components. These examples demonstrate the efficacy of GTR and RREO combination with three sources of RREO and two sources of GTR.

[0056] The combination provides synergistic and complementary benefits.

[0057] The oxidized RREO provides high temperature benefits, more Newtonian-type rheological profiles, while the GTR provides low temperature property improvement and the combination improved anti-aging properties.

Example 4

[0058] Collected re-refined (recycled) engine oils were transferred to a mixing vessel or tank as described in Example 1. The RREO was brought to a temperature of 550°±25° F. or 50° F. below the Flash Point as determined by ASTM D 92, Cleveland Open Cup Method or equivalent. As used herein RREOs can be re-refined oils or used oils that are collected and dehydrated. In the re-refining process, engine oils are collected from various sources, screened for potential hazardous materials and components, such as PCB's, etc., then dewatered, atmospherically distilled and then vacuum distilled, with the bottoms of the vacuum distillation referred to as RREO or REOB, re-refined engine oil bottoms or VTAE, vacuum tower asphalt extender. Used oils that are collected and dehydrated have lower flash point, in the range of 50-150° F., and therefore when used with GTR as described, process conditions should use the flash point for safe processing.

[0059] The RREO was mixed while air was injected at 0.1-2 L/min/kg. The reaction is a function of contact time of the RREO with air, so smaller bubbles with greater surface area are highly preferred, as is longer contact time. Preferably, air is injected as bubbles having a diameter of 0.125″ or smaller. Additionally, it is preferred to use mechanical means to minimize bubble coalescence, such as a vertical still. A non-limiting example of such a vertical still has dimension 6′ (dia.)×40 ft. (height) to 12′ (dia.)×20′ (height).

[0060] Increases in temperature from the values described in Examples 1-3 result in an increased rate of reaction, and corresponding decrease in process time. Measurements of oxidation levels in the RREO allow for adjustment of processing time, from 0.5 to 24 hours. However, in instances where RREO and GTR are jointly processed, in addition to the aforementioned parameters, internal and external circulation optimally incorporating a shear mill or digestion system facilitates the GTR size reduction, thereby enhancing the effect of the invention on asphalt binders. In determining the processing conditions, increases in temperature must be evaluated, as high temperatures can result in thermal decomposition of the GTR. RREO can be mixed with GTR at a ratio of 80% RREO to 20% GTR to 50% RREO to 50% GTR, which includes 60% RREO to 40% GTR. The GTR particles are 38 microns or less, providing large surface area for access to non-cross-linked (non-vulcanized) modular sites within the rubber particle.

[0061] Processing of the RREO or RREO and GTR to form a binder modifier should continue until the material:

[0062] achieves optimum dispersion of the GTR; and/or

[0063] Consistency/viscosity remains within desired ranges for standard means of pumping, typically using positive displacement or diaphragm pumps.

[0064] Upon reaching the desired consistency, viscosity and/or dispersion, the binder modifier, i.e. modified RREO+GTR, is added at a ratio of 80% of a standard asphalt or SBS-modified asphalt to 20% of the RREO+GTR binder modifier. The asphalt and RREO+GTR binder modifier material are mixed at 550°±25° F. or 50° F. below the flash point and applied to paving material or stored in a heated state for use in paving. Alternatively, the asphalt and RREO+GTR binder modifier material are mixed at cooler temperatures, such as 450° F., 400° F., or 50-80° F. below the flash point of the RREO.

Example 5

[0065] Collected RREO was transferred to a mixing vessel or tank as described in Example 1. The RREO was brought to a temperature of less than 450°±25° F., or at least 200° F. As used herein RREOs can be re-refined oils or used oils that are collected and dehydrated, as described in Example 4. The RREO was mixed while air was injected at 0.1-2 L/min/kg, as provided in Example 4. The reaction is dependent on RREO contact with air, thus smaller bubbles enhance contact time and reduce processing requirements. Further, due to the reduced temperatures, processing times will increase, though thermal degradation will also be correspondingly reduced. Measurements of oxidation levels in the RREO allow for adjustment of processing time, from 1 to 24 hours.

[0066] RREO can be mixed with GTR at a ratio of 80% RREO to 20% GTR to 50% RREO to 50% GTR, which includes 60% RREO to 40% GTR. The GTR particles are 38 microns or less, providing large surface area for access to non-cross-linked (non-vulcanized) modular sites within the rubber particle. Processing of the RREO or RREO and GTR to form a binder modifier should continue until the material:

[0067] achieves optimum dispersion of the GTR; and/or

[0068] Consistency/viscosity remains within desired ranges for standard means of pumping, typically using positive displacement or diaphragm pumps.

[0069] Upon reaching the desired consistency, viscosity and/or dispersion, the binder modifier, i.e. modified RREO+GTR, is added at a ratio of 80% of a standard asphalt or SBS-modified asphalt to 20% of the RREO+GTR binder modifier. The asphalt and RREO+GTR binder modifier material are mixed at a temperature of at least 400° F., or 450° F.±25° F. and applied to paver material or stored in a heated state for use in paver. Alternatively, the asphalt and RREO+GTR binder modifier material are mixed at cooler temperatures, such as 450° F., 425° F., or 400° F.

Example 6

[0070] A composition of re-refined engine oil (RREO) and ground tire rubber (GTR) was prepared. A vessel, tank or circulation loop was obtained possessing sufficient capacity to receive the selected amount of GTR via standard industry practices to include conveying, pneumatic injection or by directly dumping into the tank. In addition to the aforementioned heating capability, the vessel must be equipped with a combination of paddle agitation, high shear milling or mixing (Cowles), high velocity pump circulation, or other device designed to keep the GTR suspended and prevent settling out during the process. Preferably, the vessel will have paddle agitation, shear milling, and circulation.

[0071] The mixture of RREO and GTR was then reacted for the selected time to produce the desired admixture properties of viscosity, GTR particle size and GTR particle dispersion. In some embodiments, up to 40% GTR is mixed with the RREO. However, a higher percentage of GTR is possible. The consistency of the resulting material is dependent upon reaction parameters and type of rubber co-processed. For example, longer reaction times typically yield more oils, carbon black, and smaller GTR particulates. Reducing the GTR particle size to less than 38 microns provides greater surface area, exposing more non-cross-linked modular sites within the rubber particle (non-vulcanized). These sites may subsequently be cross-linked providing elastomeric properties.

[0072] The RREO from Example 1 was modified with GTR at a ratio of 80% RREO and 20% 40-mesh GTR. The internal high shear mixer was run for 2.8 hours with air injection at 450±10° F. The mix was N.sub.2 blanketed and processed until the targeted Softening Point of 200° F.-240° F. for use in asphalt roofing was achieved. The results of the composition are shown in Table 8.

TABLE-US-00008 TABLE 8 Results of Oxidation of RREO from Supplier 1, Modified with 40 mesh GTR from Source A. ASTM Test Properties Method Results Comments Mixing Process Temperature, ° F. Probe 450 ± 10 PRI procedure, Silverson RREO Addition Time, hours PRI 0.4 laboratory high shear mixer. Time, hours To targeted 2.8 Temperatures adjusted for GTR end point oils RREO + GTR Blend Before Processing Composition, Asphaltenes D 4124 via 12.5 Composition of RREO before Component Fractions, % Polar Aromatics Iatroscan 25.5 addition of GTR Naphthene Aromatics 0.0 Saturates 62.0 RREO + GTR Blend After Processing Flash Point, COC, ° F. D 92 480 The oils in the GTR are released, Flash Point, PMCC, ° F. D 93 465 reducing the Flash Point of the blend Softening Point, ° F. D 36 220 Selected for use in all markets Penetration, dmm 4° C. D 217 170 Demonstrates the blended 25° C. 166 products' uniform consistency 46.1° C. 196 over a wide temperature range (Newtonian-like behavior) Solubility, TCE, % D 2042 99.8 Homogeneity, 425 μm GTR particles. GTR were reduced in size, finer than 1.5 μm Rotational Viscosity, 10 rpm — Too viscous for measurement 300° F., cps 50 rpm D 4402 — 100 rpm — Separation, 163° C., 48 Top 1/3 D 7173/D 36 114 Demonstrates elimination of the hrs, SP, ° F. Bottom 1/3 115 settling issues associated with 40 Difference, ° C. 1.0 mesh GTR when processed and blended with RREO DSR, G*/sinδ, kPa 106° C. D 7175 — Exhibits lower DSR values due to 100° C. 1.260 the GTR oils. 94° C. 1.530 MSCR 0.1 kPa J.sub.nr 25° C. D 7405 0.0003 Demonstrates the ability to impart % 98.1 resiliency (% Recovery) to the Recovery blended product without the use 3.2 kPa J.sub.nr 0.3 of elastomers (SBS's) or cross- % 42.6 linking Recovery

[0073] The addition of 20% GTR reduced the processing time of RREO by approximately 60%. Further, the inclusion of GTR affected the properties of the resulting composition, including reducing the Flash Points due to the release of GTR oils. The GTR and RREO composition exhibited homogeneity without GTR settling and reduced the GTR particle size sufficiently (less than 1.5 μm) to achieve 99.8% Solubility.

[0074] The high temperature stiffness of this composition was slightly lower than the 100% RREO of Example 1, but still sufficient to achieve a PG 100-XX rating. The multiple stress creep recovery, MSCR, protocols indicated 35% Elastic Recovery at 3.2 kPa.

[0075] This product, if added to a neat PG paving binder, provides the ability to add GTR which does not settle, meets solubility requirements, does not lower the high temperature PG of host asphalt, and improves the host asphalt's low temperature properties.

Example 7

[0076] The RREO, from Example 1, was modified with GTR at a ratio of 60% RREO and 40% 40-mesh GTR. The internal high shear mixer was run for 3 hours at 450±10° F. with air injection. The composition was N.sub.2 blanketed during the process as in the previous examples. Processing continued until the targeted 160° F.-170° F. (universal asphalt markets) was met. The results of composition testing are shown in Table 9.

TABLE-US-00009 TABLE 9 Results of Oxidation of RREO from Supplier 1, Modified with GTR from Source A. ASTM Test Properties Method Results Comments Mixing Process Temperature, ° F. Probe 450 ± 10 PRI procedure, Silverson RREO Addition Time, hours PRI 1.1 laboratory high shear mixer Time, hours To targeted 2.1 end point RREO + GTR Blend Before Processing Composition, Asphaltenes D 4124 via 12.5 Composition of RREO before Component Fractions, % Polar Aromatics Iatroscan 25.5 addition of GTR Naphthene Aromatics 0.0 Saturates 62.0 RREO + GTR Blend After Processing Flash Point, COC, ° F. D 92 470 The oils in the GTR are released, Flash Point, PMCC, ° F. D 93 430 reducing the Flash Points Softening Point, ° F. D 36 165 Targeted for use in all markets Penetration, dmm 4° C. D 217 333 Demonstrates the blended products' 25° C. 304 uniform consistency over a wide 46.1° C. 331 temperature range, 4° C. to 46° C. Solubility, TCE, % D 2042 90.3 Homogeneity, 40 mesh (425 μm) GTR was reduced in size Rotational Viscosity, 10 rpm — Too viscous for measurement 300° F., cps 50 rpm D 4402 — 100 rpm — Separation, 163° C., 48 Top 1/3 D 7173/D 36 91 Demonstrates elimination of the hrs, SP, ° F. Bottom 1/3 91 settling associated with 40 mesh Difference, ° C. 0 GTR DSR, G*/sinδ, kPa 70° C. D 7175 0.91 Exhibits slightly lower DSR values 65° C. 1.03 due to the GTR oils MSCR 0.1 kPa J.sub.nr 25° C. D 7405 0.012 Demonstrates the ability to impart % 98.5 resiliency (% Recovery) to the Recovery product without the use of other 3.2 kPa J.sub.nr 0.819 elastomeric polymers or cross- % 35.2 linking Recovery

[0077] The resulting composition demonstrates the ability to process higher loadings of GTR, while still achieving homogeneity without settling. The addition of the added GTR (40%) released more GTR oils, which subsequently reduced the Softening Point and DSR values as expected. Additional processing time would increase these values proportionately. As in the previous examples, elastomeric properties were exhibited.

[0078] The product exhibited enhanced tack and stickiness. As such, this composition is useful in: host asphalts, such as paving binders, MB compounds in roofing, roofing and industrial peel-n-stick compounds, crack and joint sealants, roof coatings, cements, and mastics. The incorporation would greatly enhance a suite of performance properties.

Example 8

[0079] The RREO from Example 3 was modified with GTR at a ratio of 80% RREO and 20% 30-mesh GTR (Source B). The internal high shear mixer was run at 450±10° F. with air injection, until a targeted Softening Point of 200+° F. (universal asphalt markets) was met. The composition was N.sub.2 blanketed during the process, as in the previous samples. The results of the composition evaluations are shown in Table 10.

TABLE-US-00010 TABLE 10 Results of Oxidation of RREO from Supplies III, Modified with 30 mesh GTR from Source B ASTM Test Properties Method Results Comments Mixing Process Temperature, ° F. Probe 450 ± 10 PRI procedure, Silverson RREO Addition Time, hours PRI 0.3 laboratory high shear mixer Time, hours To targeted 2.8 end point RREO + GTR Blend After Processing Flash Point, COC, ° F. D 92 485 The oils in the GTR are released, Flash Point, PMCC, ° F. D 93 470 reducing the Flash Points Softening Point, ° F. D 36 221 Targeted for use in all markets Penetration, dmm 4° C. D 217 170 Demonstrates the products' 25° C. 166 consistency stability over a wide 46.1° C. 196 temperature range Solubility, TCE, % D 2042 99.8 Homogeneity, particulate GTR was reduced in size sufficiently Rotational Viscosity, 10 rpm — Too viscous for measurement 300° F., cps 50 rpm D 4402 — 100 rpm — Separation, 163° C., 48 Top 1/3 D 7173/D 36 114 Demonstrates elimination of the hrs, SP, ° F. Bottom 1/3 115 settling associated with 40 mesh Difference, ° C. 1.0 GTR, size reduction of the GTR DSR, G*/sin6, kPa 106° C. D 7175 — Exhibits a slightly lower DSR are 100° C. 1.260 value due to the GTR oils 94° C. 1.530 MSCR 0.1 kPa J.sub.nr 25° C. D 7405 0.0003 Demonstrates the ability to impart % 98.1 resiliency (% Recovery) to the Recovery product without the use of virgin 3.2 kPa J.sub.nr 0.03 SBS or cross-linking % 42.6 Recovery

[0080] In Example 8, the third RREO source was combined with a second source (b) of GTR. The results are similar to the results of Example 6, using RREO from Source 1 and GTR form Source 1 (a). The compound's stiffness, G*, is increased, and the rheological properties are more Newtonian, exhibiting similar consistency over a wide temperature range. Homogeneity and non-settling of the GTR was achieved, and elastomeric properties were gained.

[0081] The process time was significantly reduced with the GTR when compared to the 100% RREO, Source III data, shown in Example 3. This is consistent with other testing, and an important finding, as the “wear metals” indigenous to RREO currently available are believed to act as reaction catalysts, though other actions may be affecting the reactions. The process efficiencies are functions of the type and quantity of “wear metals” present in RREO and possibly the quantity of GTR.

Example 9

[0082] The binder modifier formed in Example 1 was added to various paving asphalts, which are not limited by grade, type, or composition at 0.5 wt % or 5 wt %, depending on the requirements of the end product. The admixture is completely miscible, yielding homogenous, stable blended asphalt. The new blended paving binder was immediately usable and complies with current specification enhanced performance properties.

TABLE-US-00011 TABLE 11 Benefits of blending 10% RREO (see Table 4) with 90% PG 58-16. Results Property ASTM Test Method PG 58-16 Neat 90/10 Blend Original Binder, As Received DSR, G*/sin δ, kPa 58° C. D 7175 1.231 1.963 PAY Residue (20 hrs. 300 psi, 100° C.) Creep m Value  6° C. D 6648 0.308 0.314 Stiffness Stiffness, MPa 284 179 Continuous PG D 6373 58.2-16.2 63.5-24.3 Effective Temperature Calculation 74.4 87.8 Range, ° C.

[0083] The modified asphalt material properties, seen in Table 11, demonstrates the improvement in both the high and low temperature properties when using oxidized RREO from Example 1 blended with a conventional PG neat binder. The overall PG was improved by nearly one high temperature grade and more than one low temperature grade. The Effective Temperature Range increased by 13.4° C.

Example 10

[0084] The binder modifier formed in Example 6 was added to various paving asphalts, which are not limited by grade, type, or composition at 0.5 wt % or 5 wt %, depending on the requirements of the end product. The admixture is completely miscible, yielding homogenous, stable blended asphalt. The new blended paving binder was immediately usable and complies with current specification enhanced performance properties, as seen in Table 12.

TABLE-US-00012 TABLE 12 Benefits of Blending RREO + GTR Admixture (see Table 8) with Standard Air Blown Shingle Coating. The blend used was 80% air blown shingle coating + 20% RREO + GTR processed blend. Results Air Blown Shingle Property ASTM Test Method Coating 80/20 Blend Original/As Blended Softening Point, ° F. D 36 210 211 Elastic Recovery, % 25° C. D 6084 Broke @ 2.6 cm 13.3 Separation, SP Difference, ° F. D 7173 1.0 1.0 MSCR, J.sub.nr 60° C. D 7405 0.0021 0.0014 Sag, 0.1 mm 140° F. D 4526 0.0 0.0 Creep m Value −12° C. D 6648 0.275 0.304 Stiffness Stiffness, MPa 90.7 39.5

[0085] The roofing blend demonstrates the utility of RREO+GTR admixture. The high temperature properties, evaluated by Softening Point, remained the same (210° F. vs. 211° F.), while the low temperature properties were improved as measured by Creep Stiffness. Additionally, the blended product exhibited approximately 13% Elastic Recovery due to the GTR component vs. no Elastic Recovery for the neat air blown shingle coating.

[0086] When 60% mineral filler was added to the two (2) coatings, the filled coating exhibited the properties noted in Table 13.

TABLE-US-00013 TABLE 13 Beneficial Properties of Prototype Filled Shingle Coatings. Results Air Blown Shingle 80/20 Blend Shingle Coating Coating 40% + 20% 40% + 60% Property ASTM Test Method Mineral Filler Mineral Filler Original/As Blended Penetration, dmm 4° C. D 5 4 16 25° C. 10 16 46.1° C. 17 20 Separation, SP Difference, ° F. D 7173 22 6 Creep m Value −12° C. D 6648 0.254 0.276 Stiffness Stiffness, MPa 445 192

[0087] The properties demonstrate a filled coating to be less elastic at low temperatures. Both the Penetration values and Creep Stiffness values provide comparative improvements of the 80/20 Filled Coating. Filler settling and measured Separation, indicated filler settling was retarded.

[0088] The 80/20 Filled Coating was added to the MB (modified bitumen coating employing plastomeric modifiers such as EVA and PE) used in commercial roofing products. Improved low temperature and elastomeric properties were confirmed. These properties are typically not found in asphalts modified with plastomers in either the roofing or paving sectors.

[0089] Additionally, the admixture improved adhesion properties to include aggregates. Initial tack and improved water sensitivity were identified. Elastomeric properties as determined by AASHTO TP 19, ASTM D 6084, and other test methods quantifying Elastic Recovery and recoverable strain were improved.

[0090] Performance improvements without an accompanying increase in viscosity are typically associated with polymer modifiers such as SBS polymers or Poly phosphoric Acid (PPA). SBS polymer and Poly phosphoric Acid (PPA) when added to bitumen, increase the Rotational Viscosity and Dynamic Shear Rheology, G*/sin δ, as measured by ASTM D 4402 and AASHTO T 315, respectively. The increases are proportionate with dosage and may result in a non-compliance with binder specifications like AASHTO M 320, Table 4. Similarly, the viscosity increase may be exhibited in asphalt binders governed by ASTM D 946, Penetration-Graded bitumen and/or ASTM D 3381, Viscosity-Graded bitumen.

[0091] Testing of the admixture-asphalt binder provided improved low temperature properties, while preserving or only minimally effecting the high temperature properties.

Example 11

[0092] The binder modifier formed in Example 3 was combined with paving aggregates to make a cold patch compound without the use of asphalt of any type. The admixture is completely miscible, yielding homogenous, stable blended asphalt. The compound consists of 96% No. 4 Trap Rock Aggregate combined with 4% processed RREO. The new blended paving binder was immediately usable and complies with current specification enhanced performance properties

TABLE-US-00014 TABLE 14 Properties of the Prototype Cold Patch Compound. ASTM Test Property Method Results Workability 10° C. D 6704, Atl. 1 24.5 25° C. 26 40° C. 23 Expected Shelf Life, lbs (Dark Oven Aged 10° D 5869 (DOA)/D 157 for 7 days @ 60° C.) 25° C. 6704 73 40° C. 59 Rut Resistance , cycles (After Dark Oven 60° C. AASHTO T 341 11.8 mm depth @ 2,210 Aged for 7 days) cycles Marshall Stability (50 blows), lbs. D 6927 1,373 Effect of Water on Marshall Stability, % (After 7 AI, MS-14, 94.3% retained days @ 60° C.) Appendix strengths

[0093] The evaluation results on the prototype cold patch materials indicated a workable rut resistance product during and after application, as seen in Table 14. The cured patch exhibited standard pavement type Marshall Stabilities and exhibited excellent aggregate adhesion and Marshall Stability after water conditioning.

Example 12

[0094] A prototype ASTM D 6690, Joint and Crack Sealant, Hot-Applied for Concrete and Asphalt Pavements, was produced using 80% of a standard SBS-modified asphalt suitable for this purpose and 20% of RREO+GTR from Example 4.

[0095] The prototype met the requirement of Type I. The prototype formula provides a significant raw material cost savings, while improving adhesion to both fractured asphalt and concrete pavements.

Example 13

[0096] RREO-GTR admixture was prepared for roofing applications. The RREO was oxidized as discussed in Example 5, and incorporated into roofing asphalt, such as base asphalt either diluted with a distillate, cutback (CB), or emulsified asphalt. Testing showed the admixture improved base asphalt for use in cutbacks, which then provided improved performance properties, adhesion, flexibility, and weatherability (resistance to cracking). Further, the admixture improved the base asphalt for use in asphalt emulsions, which then provided improved performance properties: adhesion, flexibility, and weatherability (resistance to cracking).

[0097] For steep slope shingles, and air blown coatings, the RREO was oxidized as discussed in Example 5, and incorporated into roofing asphalt, resulting in lubricating properties facilitating product manufacturing without altering high temperature properties, such as Softening Point. The lower viscosity of the coating facilitated processing and blending with filler. The admixture may also be added to flux and subsequently oxidized to coating.

[0098] The admixture-asphalt showed an improved Softening Point, as determined by ASTM D 36, and Penetration, based on ASTM D 5 relationships, as well as a high Penetration value at a given Softening Point. Further, the coating exhibited elastomeric properties seen in Example 5.

[0099] Exposure of the coating to accelerated weathering showed the admixture improved resistance to weathering as evaluated by ASTM D 4798, including mass loss and pinholes/crack formation (ASTM D 1670). Shingle coating with the RREO or RREO-GTR combination exhibited improved flexibility measured by ASTM D 5147.

[0100] In low slope and commercial roofing, and for use with modified bitumen compounds, the admixture provided complementary properties to conventional MB compounds, such as maintained performance, while reducing polymer content of compounds modified with elastomers. Further, in compounds modified with plastomers, the admixture provides a means to co-modify the composition to provide low temperature and elastomeric properties.

[0101] Other variations of usage for the asphalt compositions may be apparent to one skilled in the art.

[0102] The disclosures of all publications cited above are expressly incorporated herein by reference, each in its entirety, to the same extent as if each were incorporated by reference individually.

[0103] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall there between. Now that the invention has been described, Applicant claims the following.