Roofing material and method of manufacturing the same

Abstract

The roofing bitumen composition comprises 9 to 60 percent of a material selected from the group consisting of paving-grade bitumen feedstock, low-MW polyolefins, and kraft lignin, recycled fibrous materials, bitumen recovered from recycled asphalt shingles (RAS), recycled asphalt pavement (RAP), recycled tire rubber (RTR), and combinations thereof. This roofing bitumen composition has a calculated scope 3 carbon footprint reduction of about 5% to 60%.

Description

Technology Field

[0001] The present technical field generally relates to bitumen compositions and methods for preparing bitumen compositions. More specifically, the present technical field relates to bitumen compositions for roofing applications and methods for preparing the same. Background Technology

[0002] Bitumen is typically collected, synthesized, and refined for use in paving and roofing applications. The type of bitumen suitable for paving applications is commonly referred to as "pavement-grade bitumen" or "pavement bitumen." Typically, road bitumen will have a penetration grade ranging from 15 to 450, where 1 penetration unit is equivalent to 0.1 mm of penetration according to ASTM D 946. For pavement bitumen, the most commonly used range is 25 to 200. Bitumen suitable for roofing applications is commonly referred to as "roofing flux," "flux bitumen," or simply "flux." Approximately 90% of bitumen is road-grade, whereas roofing bitumen accounts for about 10%. Generally, pavement bitumen is harder than roofing flux. In fact, roofing flux is too soft for initial use, especially for the manufacture of roofing shingles.

[0003] A process known as "air blowing" or "oxidation" is applied to roofing flux to make it harder and, thus, more suitable for roofing applications. The product of this air blowing process is called "blown coating," or "oxidized asphalt" or "oxidized bitumen," which includes materials derived from blowsteel and recovered from RAP and RAS, and is suitable for use in manufacturing roofing products, such as roofing shingles. In the "air blowing" process, roofing-grade bitumen is heated to over 500°F (260°C) for 5 to 8 hours. Heated air is blown through the heated roofing-grade bitumen to oxidize the material, forming oxidized bitumen. This process inherently generates large amounts of greenhouse gases and other distillation off-gases. Large amounts of greenhouse gases are generated from the off-gasified material as well as the energy required to maintain the elevated temperature of the material.

[0004] For roofing applications, oxidized bitumen can be applied directly to roof structures, or aggregates can be sprayed onto the bitumen and compressed into it to form a built-up roofing membrane or sheet. Alternatively, flux bitumen or oxidized bitumen can be coated onto glass fiber, polyester, or other sheet materials to form a membrane or single. Inorganic fillers, such as mineral fillers, can also be mixed into the flux bitumen or oxidized bitumen for roofing applications. Additional components, such as recycled materials, performance additives, or combinations thereof, may be added to the bitumen.

[0005] High-temperature performance additives, e.g., plastomers and / or elastomers, and / or low-temperature performance additives, e.g., process oils, can be incorporated into bitumen materials to alter their material properties. High-temperature performance additives tend to increase the modulus of bitumen materials at higher temperatures, thereby resisting permanent deformation and creep, whereas low-temperature performance additives tend to increase the flexibility and ductility of bitumen materials at lower temperatures, thereby resisting brittleness and cracking. While the roofing industry continues its efforts to develop a balance between physical properties and environmental factors, greenhouse gas emissions and energy consumption during the manufacturing of roofing products remain ongoing challenges for the industry.

[0006] Accordingly, it is desirable to provide a bitumen composition for producing roofing products having a reduced carbon footprint while maintaining acceptable material properties. It is also desirable to provide a method for manufacturing such a bitumen composition. Furthermore, it is desirable to provide a method and composition for forming roofing bitumen products using less expensive and more readily available packaging-grade bitumen. Additional beneficial features and properties of the bitumen composition will become apparent from the following detailed description and examples.

[0007] The roofing bitumen composition is formed from packaging-grade bitumen. The roofing bitumen composition comprises 9 to 60% of a material selected from the group consisting of packaging-grade bitumen feedstock, low molecular weight synthetic polyolefins, and kraft lignin, recycled fibrous materials, bitumen recovered from closed roofing singles, shredded waste tire rubber, and combinations thereof. This roofing bitumen composition reduces the carbon footprint of traditional bitumen roofing materials and has excellent properties. The carbon footprint, determined by the reduction of greenhouse gases generated through the production of the roofing bitumen composition, is calculated to be about 5% to 60% compared to conventional roofing bitumen compositions according to the roofing bitumen composition and manufacturing method disclosed herein.

[0008] Another exemplary embodiment provides a roofing bitumen composition as described above, having a softening point of 88°C to 160°C and a penetration of at least 15 dmm at 25°C, and further comprising about 80% to about 95% by weight of packaging-grade bitumen feedstock, 5% to 20% of crushed waste tire rubber, 1% to 5% by weight of oxidized high-density polyethylene homopolymer, alkylene maleic anhydride, or a combination thereof, all amounts based on the total weight of the roofing bitumen composition.

[0009] Another exemplary embodiment provides a roofing bitumen composition as described above, having a softening point of 88°C to 160°C and a penetration of at least 15 dmm at 25°C, further comprising about 70% to about 95% by weight of packaging-grade bitumen feedstock, 5% to 30% of kraft lignin, 1% to 5% by weight of oxidized high-density polyethylene homopolymer, alkylene maleic anhydride, or a combination thereof, all amounts based on the total weight of the roofing bitumen composition.

[0010] Another exemplary embodiment provides a roofing bitumen composition as described above, further comprising about 30% by weight to about 60% by weight of paving-grade bitumen feedstock, having a softening point of 88°C to 160°C and a penetration of at least 15 dmm at 25°C, 30% by weight to 60% by weight of bitumen recovered from recycled asphalt shingles (RAS) or recycled asphalt pavements (RAP), 1% to 5% by weight of oxidized high-density polyethylene homopolymer, alkylene maleic anhydride, polyethylene homopolymer, Fischer-Tropsch wax, or a combination thereof, all amounts based on the total weight of the roofing bitumen composition.

[0011] According to another exemplary embodiment, a method for preparing a roofing bitumen composition for use in roofing applications is provided. The roofing bitumen composition is prepared by a method comprising the step of mixing 10% to 95% by weight of paving-grade bitumen feedstock, 1% to 20% by weight of polyolefin, and 5% to 60% by weight of a carbon footprint reduction material selected from the group consisting of kraft lignin, recycled fibrous material, bitumen recovered from closed roofing single or recycled asphalt pavement (RAP), crushed waste tire rubber, and combinations thereof, all amounts based on the total weight of the roofing bitumen composition. This material may be prepared by mixing the materials at an elevated temperature using a low-shear mixer speed. This method produces a roofing bitumen composition having a reduced carbon footprint with a 5% to 60% reduction in greenhouse gas emissions compared to oxidized bitumen derived from oxidized roof-grade bitumen. Specific details for implementing the invention

[0012] The following description is for illustrative purposes only and is not intended to limit the invention or its application and use. Furthermore, there is no intention to be bound by any prior art or any theories presented in the following description.

[0013] The various embodiments considered herein relate to roofing-grade bitumen compositions having a significantly reduced carbon footprint compared to previous roofing-grade bitumen compositions. In this regard, the production of the bitumen compositions described herein can be produced with significantly less energy compared to roofing-grade bitumen using an "air blow" process, where the roofing-grade bitumen is heated to over 500°F for 5 to 8 hours and oxidized to obtain desired material properties. Due to the lower energy requirements for producing the bitumen compositions, the bitumen compositions are considered to have a reduced carbon footprint compared to conventional bitumen compositions.

[0014] Various embodiments considered may be used to form roofing products, including, without limitation, roofing singles, roofing membranes (also known as roll roofing), and waterproofing membranes for various construction applications (tunnels, commercial and residential buildings, etc.). In exemplary embodiments, the bitumen composition comprises packaging-grade bitumen, which may include oxidized bitumen. It is worth noting that the presence of polyolefins, e.g., low molecular weight polyolefins, or oxidized polyethylene homopolymers in the bitumen composition increases and improves heat resistance properties, but generally does not impair other important properties of the roofing product, such as low-temperature bending, softening point, penetration, and viscosity, in a negative way, even when the bitumen composition contains other components, such as inorganic fillers, recycled materials, performance additives, or combinations thereof. The bitumen composition also comprises carbon footprint reduction materials selected from the group consisting of kraft lignin, fibrous materials, bitumen recovered from closed roofing singles, shredded waste tire rubber, and combinations thereof. Other well-known additives, such as oils, plasticizers, and antioxidants, may also be included. A method for producing a bitumen composition is also provided.

[0015] While I do not wish to be bound by theory, greenhouse gas emissions during the production of bitumen roofing products are believed to occur primarily during the "air blow" or "oxidation" processes. Although these processes enhance the material properties required for roofing applications, the manufacturing process results in increased energy consumption as well as gas emissions. These issues regarding emissions and energy usage must be managed. In addition to environmental problems associated with manufacturing, significant emissions and energy consumption reduce the profitability of roofing manufacturers.

[0016] The characteristics of roofing bitumen compositions are established by industry standard tests. These tests to characterize the characteristics of roofing bitumen compositions include penetration (D5, Test Method for Penetration of Bituminous Materials), softening point (D36, Test Method for Softening Point of Bitumen), flash point and combustion point (D92, Test Method for Ductility of Bituminous Materials), and solubility (D2402, Test Method for Solubility of Asphalt Materials in Trichloroethylene). Additionally, the characterization of roofing bitumen compositions includes weathering tests, ASTM D 4798, and standard practices regarding accelerated weathering test conditions and procedures for bituminous materials.

[0017] Similarly, as familiar and understood to those skilled in the art, other characteristics of bitumen compositions intended for use in bitumen roofing products are important, quantified, and monitored. For example, the low-temperature bending temperature is the minimum temperature at which a sample of bitumen composition will not fracture or crack under bending. For bitumen compositions useful for roofing applications, the acceptable low-temperature bending temperature is about -20°C (-4°F) or lower for SBS-modified bitumen roofing membranes and -5°C (23°F) or lower for atactic polypropylene (APP)-modified bitumen roofing membranes. For roofing singles in the United States, the acceptable low-temperature bending temperature is about 25°C (77°F).

[0018] In addition, bitumen compositions do not have a distinct melting point, but rather have a temperature range in which the material begins to soften without melting and continues to soften. It is beneficial to know the temperature range in which a bitumen composition becomes too soft for use in construction and manufacturing; therefore, the softening point of a bitumen composition is an important characteristic that must be measured. Bitumen compositions suitable for use in roofing applications and products must have a softening point of about 87.8 to about 160°C (about 190 to about 320°F).

[0019] The penetration test provides a measure of the viscosity of bitumen feedstock at a given temperature. Viscosity is a function of the type of chemical composition of the bitumen and their relative amounts within the bitumen, which is determined by the crude oil and the processing methods used at the refinery. Penetration is measured using a standard needle that is allowed to penetrate the bitumen for a period of time, such as 5 seconds, while the temperature of the specimen is maintained at a specific value, such as 25°C. Penetration is measured in tenths of a millimeter (deci-millimeter, 0.1 mm, dmm), and the deeper the needle penetrates the bitumen specimen, the higher the reported value and the softer the bitumen becomes.

[0020] Additionally, a bitumen composition intended for use in bitumen roofing products may have a penetration value greater than about 10 dmm (0.1 millimeters), such as greater than about 12 dmm, at 25°C. It is preferable that the bitumen composition have a penetration value greater than about 10, 12, 15, 20, or 25 in dmm units and independently less than or equal to about 75, 70, 60, 55, 50, 45, 40, 35, 30, 25, or 20.

[0021] As mentioned above, the bitumen compositions considered herein include packaging-grade bitumen feedstocks, low molecular weight polyolefins, and carbon footprint reduction materials. All types of bitumen feedstocks, naturally occurring, synthetically produced, and modified, may be used according to the bitumen compositions considered herein. Naturally occurring bitumen include natural rock bitumen, lake bitumen, etc. Synthetically produced bitumen are generally by-products of petroleum refining operations, blended bitumen, decomposed residue or recycled bitumen, petroleum bitumen, propane bitumen, straight-run bitumen, thermal bitumen, etc. Modified bitumen includes base bitumen modified with elastomers, plastomers, or various combinations thereof (e.g., untreated or unmodified bitumen that may occur naturally or be synthetically produced).

[0022] The bitumen Performance Grade (PG) evaluation system classifies bitumen compositions used in bitumen products based on the performance of the bitumen composition at different temperatures. For example, a bitumen composition with a PG grade of approximately 64-22 means that the bitumen composition can be used in climates where the packaged final product reaches temperatures as high as +64°C and as low as -22°C. Temperatures outside the PG range of a bitumen composition usually result in the degradation of the bitumen product in which that bitumen composition is used.

[0023] The term “base bitumen” as used herein refers to bitumen, or a dark brown to black cementitious material whose main component is bitumen that occurs naturally or is obtained from petroleum processing, as defined by ASTM D 8. Bitumen typically contains saturated compounds, aromatics, resins, and asphaltenes.

[0024] The type of paving bitumen suitable for paving applications is commonly referred to as "paving grade bitumen," "paving bitumen," or "bitumen cement." Bitumen suitable for roofing applications is commonly referred to as "roofing flux," "flux bitumen," or simply "flux." Generally, as indicated by their penetration grades, paving bitumen is harder than roofing flux. The most commonly used paving bitumen has a penetration of approximately 50 / 70 or 60 / 90 dmm (0.1 millimeters) at 25°C, whereas the penetration of roofing flux generally exceeds 150 to 200 dmm at 25°C. Therefore, because roofing flux is too soft, it would not be used directly, particularly in the manufacture of roofing shingles. As described above, the "air blow" process is applied to roofing flux to make it harder and, thus, more suitable for roofing applications. During the air blow process, air is bubbled through the high-temperature liquid roofing flux for a certain period of time (e.g., 2 to 8 hours). Oxygen in the air reacts with the bitumen flux, thereby dramatically increasing its stiffness, which is shown to cause the penetration of the roofing flux to drop from over 150 to 200 dmm to about 20 dmm. The product of this air blow process is called "blown coating" or "oxidized bitumen" and is useful for manufacturing roofing products, such as roofing singles.

[0025] The term "non-oxidized base bitumen" as used herein includes base bitumen that has not undergone or undergone oxidation or air blowing as described herein. In other words, packaging-grade bitumen or roofing flux-type bitumen is used in the bitumen compositions considered herein without first performing an air blowing step to cure it before combining it with low molecular weight (MW) polyolefins or inorganic fillers, recycled materials, performance additives, etc.

[0026] Adding a low MW polyolefin to a bitumen composition in an amount of about 0.1 to about 15 weight percent improves the heat resistance properties of the bitumen composition and the roofing product comprising such bitumen composition. The term “low MW polyolefin” as used herein refers to a polyolefin-containing polymer or a blend of two or more polyolefin-containing polymers, each having a weight average molecular weight (M) of about 500 to about 30,000 daltons. w It has ) and comprises one or more olefin monomers selected from ethylene, propylene, butene, hexene, and octene in an amount of about 80 to about 100 wt% based on the total weight of the low MW polyolefin. Accordingly, the low MW polyolefin may be a homopolymer comprising only a single type of olefin monomer, or a copolymer comprising two or more types of olefin monomers. Additionally, the term low MW polyolefin as used herein includes, but is not limited to, polyolefin waxes, i.e., polyolefins that are solid at or near room temperature and have low viscosity when exceeding their melting point. The low MW polyolefin may be functionalized. The functionalized low MW polyolefin may be a homopolymer or a copolymer. Additionally, the functionalized low MW polyolefin comprises one or more functional groups, for example, without limitation, including acids, esters, amines, amides, ethers, and anhydrides. Additionally, low MW polyolefins can be oxidized.

[0027] In an exemplary embodiment, the low MW polyolefin has an olefin content of about 50 to about 100 wt% based on the total weight of the low MW polyolefin. It is preferable that the low MW polyolefin has an olefin content of at least about 55, 60, 65, 70, 75, 80, 85, 90, or 95 in wt% based on the total weight of the low MW polyolefin, and independently about 98, 95, 92, 90, 85, 80, or 75 or less.

[0028] As previously mentioned, low MW polyolefins have an M of about 500 to about 30,000 daltons. w The low MW polyolefin has M in Daltons of at least about 500, 1,000, 2,000, 3,000, 4,000, 5,000, 6,000, 7,000, 8,000, or 9,000, and independently about 30,000, 28,000, 26,000, 24,000, 22,000, 20,000, 18,000, 15,000, 12,000, or 10,000 or less. w It is desirable to have... If the low MW polyolefin comprises a combination of more than one type of polyolefin, the M of each type of polyolefin within such combination w Individually, it will be within the above-specified range of about 500 to about 30,000 daltons.

[0029] Generally, suitable low-MW polyolefins include, without limitation, polyethylene homopolymers, polypropylene homopolymers, copolymers of two or more of ethylene, propylene, butene, hexane, and octene, functionalized derivatives of said homopolymers, functionalized derivatives of said copolymers, or combinations of unfunctionalized and functionalized low-MW polyolefins. Thermally decomposed (TD) waxes and Fischer-Tropsch (FT) waxes produced from virgin or recycled plastic waste, i.e., those satisfying the above-defined characteristics of low-MW polyolefins, may also be used in the bitumen compositions considered and described herein.

[0030] Examples of suitable functionalized low-MW polyolefins include, without limitation, alkylene maleic anhydrides, maleated polyethylene, maleated polypropylene, ethylene acrylic acid copolymers, ethylene vinyl acetate copolymers, oxidized polyethylene, particularly oxidized high-density polyethylene, and combinations thereof. The alkylene maleic anhydride may be ethylene maleic anhydride, propylene maleic anhydride, or a combination thereof. Alternatively, the produced TD wax is produced from virgin or recycled plastic waste. High-density polyethylene (HDPE) has a very low molecular weight (500 to 30,000 daltons; LMW) or a very high molecular weight (> 10 6 It is a commercially available material having a Dalton (HMW) chain. In this disclosure, oxidized high-density polyethylene is about 0.94 to about 1.0 gm / cm³ at 23 + / - 0.1°C as determined by ASTM D 1505. 3 It is defined as polyethylene having a density of .

[0031] One category of suitable low-MW polyolefins includes specific HONEYWELL TITAN® polyolefins, which comprise homopolymers of polyethylene or polypropylene and are commercially available from Honeywell International Inc., located in Charlotte, North Carolina, USA. More specifically, one or more of HONEYWELL TITAN® 8880, 8570, 8650, 8903, and 8822 are suitable for use as low-MW polyolefins.

[0032] In exemplary embodiments, low MW polyolefins include functionalized high-density polyethylene such as Honeywell Titan® 8903 and Honeywell Titan 8058, propylene maleic anhydride copolymer such as Honeywell Titan 8822, and low-density polyethylene (LDPE) homopolymers such as Honeywell Titan 8422 and Honeywell Titan 8183.

[0033] In an exemplary embodiment, the low MW polyolefin is present in the bitumen composition in an amount of about 0.1 to about 15 weight percent (wt%) of the bitumen composition. It is preferable that the low MW polyolefin be present in the bitumen composition in an amount of at least about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.2, 1.5, 1.8, 2.0, 2.2, 2.5, or 3.0 in wt% based on the total weight of the bitumen composition, and independently about 15, 12, 10, 8, 6, 5, 4.5, 4.0, 3.5, 3.0, 2.5, 2, 1.5, 1.4, 1.3, 1.2, 1.1, or 1 or less. For example, the total content of low-MW polyolefin in the bitumen composition may be about 0.5 to about 10 wt%, or about 0.5 to about 7 wt%, or about 1 to about 6 wt%, or about 2 to about 5 wt%, or even about 0.5 to 2.0 wt% based on the total weight of the bitumen composition.

[0034] Performance additives such as plastomers, elastomers, or both are well known in the industry to be used in bitumen roofing products to extend the temperature range in which the bitumen product can be used without serious defects or breakage. The bitumen composition may comprise one or more performance additives present in a total amount of about 1 to about 20 wt%, and preferably about 5 to about 15 wt%, based on the total weight of the bitumen composition. Non-limiting examples of elastomers suitable for modifying non-oxidized base bitumen include natural or synthetic rubbers comprising styrene / conjugated diene block or random copolymers such as styrene / butadiene, styrene / isoprene, styrene / propylene / diene (EPDM) terpolymer, ethylene / n-butyl acrylate / glycidyl methacrylate terpolymer, and, for example, styrene / butadiene / styrene copolymer (SBS), styrene / butadiene, styrene / isoprene, styrene / isoprene / styrene (SIS), and styrene / isoprene-butadiene block copolymer. Block copolymers can be branched or linear, and can be diblock, triblock, tetrablock, or multiblock.

[0035] In some embodiments of the bitumen composition considered and described herein, an elastomer, such as recycled tire rubber, may be present in an amount of about 1 to about 20 wt% based on the total weight of the bitumen composition. For example, in some embodiments, the elastomer is present in the bitumen composition in an amount of at least about 1, 2, 3, 5, 7, 8, or 9 in wt% based on the total weight of the bitumen composition, and independently about 15, 14, 13, 12, 11, 10, or 9 or less. In an exemplary embodiment, the elastomer is an SBS copolymer and is present without limitation based on the total weight of the bitumen composition in an amount of, for example, about 5 to about 15 wt%, or about 6 to about 13 wt%, or about 8 to about 12 wt%, or about 8 to about 11 wt%, or even about 9 to 10 wt%. In an embodiment of a bitumen composition for use in roofing applications and products comprising recycled tire rubber, the amount of low-MW polyolefin present and still providing performance benefits may be as small as only about 2 wt% or less, or even 1.2 wt% or less, based on the total weight of the bitumen composition. The recycled tire rubber may be ground to a size of about 20 to about 200 mesh and preferably about 40 to mesh, more preferably about 60 to about 200 mesh, and even more preferably about 80 to about 200 mesh.

[0036] For example, non-limiting examples of plastomers suitable for modifying the base bitumen for high-temperature performance include thermoplastic polyolefins that soften when heated but melt only at significantly higher temperatures, such as polyethylene, oxidized polyethylene, polypropylene, oxidized polypropylene, and functionalized polyolefins, such as maleated polyethylene, maleated polypropylene, ethylene acrylic acid copolymer, etc.

[0037] In an exemplary embodiment, the roofing bitumen composition is formed from a packaging-grade bitumen feedstock. The roofing bitumen composition comprises 5 to 60% of a material selected from the group consisting of packaging-grade bitumen feedstock, low-MW polyolefin, and kraft lignin, recycled fibrous material, bitumen recovered from closed roofing singles, crushed waste tire rubber, and combinations thereof.

[0038] Another exemplary embodiment provides a roofing bitumen composition as described above, having a softening point of 88.9°C to 112.8°C and a penetration of at least 15 dmm at 25°C, and further comprising less than about 91 wt% and more than about 82 wt% of packaging-grade bitumen feedstock. Such packaging-grade bitumen feedstock may be formed of 9.0 to 15.0 wt% recycled shredded rubber, 2 to 4 wt% oxidized high-density polyethylene homopolymer, and 1 to 2 wt% propylene maleic anhydride. Such a roofing bitumen composition reduces the carbon footprint from traditional bitumen roofing materials and has excellent properties.

[0039] Another exemplary embodiment provides a roofing bitumen composition as described above, having a softening point of 89.5°C to 114.2°C and a penetration of at least 15 dmm at 25°C, and further comprising about 76 wt% to about 95 wt% of packaging-grade bitumen feedstock, 5% to 20% of kraft lignin, 1 to 3 wt% of oxidized high-density polyethylene homopolymer, and 1 to 3 wt% of propylene maleic anhydride. This roofing bitumen composition reduces the carbon footprint from traditional bitumen roofing materials and has excellent properties.

[0040] Another exemplary embodiment provides a roofing bitumen composition as described above, having a softening point of 94.0°C to 107.6°C and a penetration of at least 15 dmm at 25°C, comprising about 37 wt% to about 50 wt% of paving-grade bitumen feedstock, 50 wt% to 60 wt% of bitumen recovered from recycled asphalt shingles (RAS) or recycled asphalt pavements (RAP), 3 wt% of oxidized high-density polyethylene homopolymer, alkylene maleic anhydride, polyethylene homopolymer, Fischer-Tropsch wax, or a combination thereof, all amounts based on the total weight of the roofing bitumen composition. This roofing bitumen composition reduces the carbon footprint of traditional bitumen roofing materials and possesses excellent properties.

[0041] According to another exemplary embodiment, a method for preparing a roofing bitumen composition for use in roofing applications is provided. The roofing bitumen composition is prepared by a method comprising the step of mixing 35% to 95% by weight of paving-grade bitumen feedstock, 1% to 5% of low-MW polyolefin, and 5% to 60% by weight of a carbon footprint reduction material selected from the group consisting of kraft lignin, recycled fibrous material, bitumen recovered from closed roofing single (RAS) or recycled asphalt pavement (RAP), crushed waste tire rubber, and combinations thereof. This material may be prepared by mixing the materials at an elevated temperature using various mixer speeds. This method produces a roofing bitumen composition having a reduced carbon footprint with a 5% to 60% reduction in greenhouse gas emissions compared to oxidized bitumen derived from roof-grade bitumen. The carbon footprint reduction material and low MW polyolefin are added to a base bitumen (e.g., NA PG 64-22 #1) melted at 140°C to about 200°C. The mixture can be blended using a high-shear or low-shear mixer at about 200 to about 20,000 rpm, preferably 3,000 rpm, for about 1 to about 4 hours.

[0042] In an exemplary embodiment, a bitumen material is provided that is useful for producing roofing products and contains the bitumen composition described herein. This filled bitumen material comprises the roofing bitumen composition described and an inorganic filler. Based on the total weight of the filled bitumen material, the bitumen composition is generally present in the filled bitumen material in an amount of about 20 to about 99 wt%, preferably 30 to 60 wt%, and the inorganic filler is present in a total amount of about 1 to about 80 wt%, preferably 20 to 70 wt%.

[0043] Inorganic fillers suitable for addition to filled bitumen materials for roofing applications such as those described herein may be any inorganic filler, crushed recycled asphalt pavement (RAP), crushed recycled asphalt single (RAS), or a combination thereof that is currently or in the future known to those skilled in the art as suitable for inclusion in roofing products. Depending on the intended use of the filled bitumen material, i.e., paving or roofing, and in the case of roofing, bitumen roofing single, membrane, or waterproofing membrane, the inorganic filler may be a mineral filler, fly ash, carbon black, or a combination thereof. Mineral fillers are typically crushed stone or minerals, such as, for example, stone powder, limestone particles, and talc. Inorganic fillers, crushed RAP, and crushed RAS are typically crushed to a particle size of about 180 μm or less.

[0044] The fibrous material may be long or short fibers formed from natural, synthetic, or mineral fibers. These materials may be recycled or reused fibers. Optionally, the fibrous material may be kraft lignin obtained from kraft pulp. Pulping process In this, cracks occur in the lignin macromolecule, and molecular weight It decreases, and lignin dissolves in alkaline solutions, turning the solution dark brown.

[0045] In an exemplary embodiment, the filled bitumen material is formulated for roofing purposes, and the inorganic filler is crushed stone or mineral. The filled bitumen material comprises a bitumen composition and an inorganic filler present in amounts of about 20 to about 99 wt% and about 1 to about 80 wt%, respectively, of the filled bitumen material. The bitumen composition itself comprises a non-oxidizing base bitumen, a low-MW polyolefin, a carbon footprint reduction material, and optionally one or more performance additives, e.g., an elastomer, a plastomer, or a combination thereof. Based on the total weight of the bitumen composition, the low-MW polyolefin is present in amounts of about 1 to about 20 wt% and about 1 to about 5 wt%, respectively, and the carbon footprint reduction material is present in amounts of about 5 to about 60 wt%.

[0046] In an exemplary embodiment, a method for preparing a filled bitumen composition is provided. The method comprises the step of combining a low MW polyolefin, a non-oxidizing base bitumen, and a carbon footprint reduction material at an elevated temperature to form an unfilled bitumen composition or a recycled material.

[0047] Unfilled bitumen compositions can be prepared by mixing materials at elevated temperatures using various mixer speeds. This method produces unfilled bitumen compositions with a reduced carbon footprint, along with a 5 to 60% reduction in greenhouse gas emissions compared to oxidized bitumen derived from loop-grade bitumen. Carbon footprint reduction materials and low MW polyolefins are added to molten base bitumen (e.g., NA PG 64-22 #1) at about 140°C to about 200°C. The mixture can be blended for 1 to 4 hours at about 200 to about 20,000 rpm, preferably 3,000 rpm, using a high-shear or low-shear mixer. The filler is then combined with the unfilled bitumen composition to form a filled bitumen composition. The filled bitumen composition can be prepared by mixing the unfilled bitumen composition and the filler at elevated temperatures using various mixer speeds. In one example, the unfilled bitumen composition and the filler are mixed using a mixer at about 200 to about 2,000 ROM for about 1 to about 4 hours at about 140°C to about 200°C.

[0048] In another exemplary embodiment, a carbon footprint reduction material and a low MW polyolefin are mixed to form a blend, which is then combined with a non-oxidizing base bitumen at an elevated temperature to form a bitumen composition. The blend may be a physical mixture of the two, a molten blend that can be formed into flakes, pellets, briquettes, or other shapes before being cooled and combined with the non-oxidizing base bitumen, or a molten blend that is added directly to the non-oxidizing base bitumen. In another example, the carbon footprint reduction material and the low MW polyolefin are individually added to the non-oxidizing base bitumen at an elevated temperature to form a bitumen composition. At least a portion of the carbon footprint reduction material may be added to the non-oxidizing base bitumen prior to, simultaneously with, or after the addition of the low MW polyolefin.

[0049] Examples

[0050] The following are examples of roofing bitumen compositions modified with low-MW polyolefins, carbon footprint reduction materials, and reduced greenhouse gas and energy requirements, with each component presented in weight percent. Examples are provided for illustrative purposes only and are not intended to limit various embodiments of the bitumen composition in any way.

[0051] Test Method Summary: Softening Point, °C (SP): Measured according to the ASTM D36 method ("ring and ball" method, "R&B SP"). Penetration, dmm at 25 °C (PEN): Measured according to the ASTM D5 method. Molecular Weight, M w All molecular weights reported in this embodiment are weight-average molecular weights measured by gel permeation chromatography (GPC), a technique generally known in the art. For the purpose of GPC, the sample to be measured is dissolved in 1,2,4-trichlorobenzene at a concentration of 2.0 mg / ml at 140°C. This solution (200 μL) is injected into a GPC comprising two PL-gel 5 μm Mixed-D (300 × 7.5 mm) columns maintained at 140°C with a flow rate of 1.0 mL / min. The instrument is equipped with two detectors (refractive index and viscosity detectors). The molecular weight (Mw) is determined using a calibration curve generated from a set of linear polyethylene narrow-dispersion Mw standards.

[0052] In the following examples, only the scope 3 carbon footprint is used for calculation. The present invention may potentially provide a greater reduction in carbon footprint than that presented in the following examples due to a potential reduction in processing temperature and processing time compared to the traditional "air blow" process used today to produce oxidized bitumen (or blown coating) for roofing product production. For non-oxidized base bitumen (e.g., NA PG 64-22 #1), the "published by the Asphalt Institute in 2019 Asphalt Institute: LCA of Asphalt Binder " middle " Life Cycle Assessment of Asphalt Binder, 2019, Executive Summary A Scope 3 carbon footprint of 0.64 kgCO2e / kg [GWP100] was used for calculations based on reference to ". For oxidized bitumen, a Scope 3 carbon footprint of approximately 0.80 to approximately 1.00 kgCO2e / kg [GWP100] was used based on Honeywell's internal calculations. For carbon footprint reduction materials such as bitumen recovered from recycled tire rubber (RTR), kraft lignin, closed-roofing single (RAS), or recycled asphalt pavement (RAP), a Scope 3 carbon footprint of 0 kgCO2e / kg [GWP100] was used to calculate the carbon footprint values ​​of various compositions in the following examples due to their waste (recycled) characteristics.

[0053] Example 1 demonstrates the effects of different amounts of paving bitumen, low-MW polyolefin, and recycled tire rubber (RTR) on the physical properties and carbon footprint of looping bitumen. Paving-grade bitumen was heated in a metal can to an elevated temperature of approximately 180°C to form high-temperature liquid bitumen, and low-MW polyolefin and recycled tire rubber (RTR) were added to the molten base bitumen (NA PG 64-22 #1) at approximately 180°C. The mixture was blended using a low-shear mixer at approximately 800 rpm for approximately 4 hours. Sample compositions and test results are shown in Table 1 below.

[0054] Softening point and penetration tests were performed on each sample using the prescribed ASTM method. Also shown are the calculated Scope 3 carbon footprint for each mixture, as well as the expected reduction (in kgCO2e units) relative to oxidized bitumen using both 1.0 and 0.8 kgCO2e for oxidized bitumen.

[0055] [Table 1]

[0056]

[0057]

[0058] Penetration, dmm as measured according to ASTM Method D5

[0059] Softening point, C

[0060] As measured according to ASTM method D36; underlined values ​​are not allowed

[0061] C RTR = Control group including recycled rubber tires

[0062] B RTR = Blended with recycled rubber tire material

[0063] Underlined results are not allowed

[0064] Honeywell Titan® 8903: Oxidized high-density polyethylene homopolymer

[0065] Honeywell Titan® 8822: Propylene maleic anhydride

[0066] Example 2 demonstrates the effect of different amounts of fibrous materials, such as packaging bitumen, Honeywell Titan® 8903, Honeywell Titan® 8822, and recycled kraft lignin, on the carbon footprint of a roofing bitumen material. Packaging-grade bitumen (NA PG 64-22) was heated in a metal can to an elevated temperature of approximately 160°C to form hot liquid bitumen, and low-MW polyolefin and kraft lignin were added to the hot liquid bitumen. The mixture was blended using a high-shear mixer at 3,000 rpm for 1 hour at 160°C. Sample compositions and test results are shown in Table 2 below.

[0067] Softening point and penetration test results were determined for each sample using the ASTM method. In addition, the calculated Scope 3 carbon footprint for each mixture, as well as the estimated reduction in oxidized bitumen (in kg CO2eq units) using both 1.0 and 0.8 kg CO2eq for oxidized bitumen, are presented.

[0068] [Tables 2a and 2b]

[0069]

[0070]

[0071] Legend

[0072] CL = Control group lignin

[0073] BL = Blend Lignin

[0074] Underlined results are not allowed

[0075] Honeywell Titan® 8903: Oxidized high-density polyethylene homopolymer

[0076] Honeywell Titan® 8822: Propylene maleic anhydride

[0077] Example 3: Effects of different amounts of packaging bitumen, low-MW polyolefin, and recycled bitumen roofing material on the physical properties of roofing bitumen compounds and Scope 3 carbon footprints. A roofing bitumen composition is prepared by a method comprising the step of mixing packaging-grade bitumen feedstock, low-MW polyolefin, and bitumen recovered from closed roofing materials. This material can be prepared by mixing the materials at about 180°C for about 1 hour using a low-shear mixer at about 800 rpm. This method produces a roofing bitumen composition having a reduced Scope 3 carbon footprint with a 5 to 60% reduction in greenhouse gas emissions compared to oxidized bitumen derived from oxidized roof-grade bitumen.

[0078] Softening point and penetration test results were determined for each sample using the ASTM method. Also shown are the calculated Scope 3 carbon footprint for each mixture, as well as the expected reduction (in kgCO2e units) relative to oxidized bitumen using both 1.0 and 0.8 kgCO2e.

[0079]

[0080]

[0081]

[0082] CL = Control group recycling looping single

[0083] BL = Blend, Recycle, Looping, Single

[0084] Underlined results are not allowed

[0085] Honeywell Titan® 8903: Oxidized high-density polyethylene homopolymer

[0086] Honeywell Titan® 8822: Propylene maleic anhydride

[0087] Honeywell Titan® 8422: Low-density polyethylene homopolymer

[0088] Honeywell Titan® 8183: Low-density polyethylene homopolymer

[0089] Honeywell Titan® 8058: Oxidized high-density polyethylene homopolymer

[0090] Sasobit®: Fischer-Tropsch Wax

[0091] Honeywell RF-1000: Fisher-Tropsch Wax

[0092] Although at least one exemplary embodiment has been presented in the foregoing detailed description, it should be understood that a vast number of variations exist. It should also be understood that the exemplary embodiments or exemplary embodiments are merely examples and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide a convenient roadmap for those skilled in the art to implement exemplary embodiments of the invention, and it is understood that various changes may be made to the function and arrangement of the elements described in the exemplary embodiments without departing from the scope of the invention as set forth in the appended claims and their legal equivalents.

Claims

Claim 1 A roofing bitumen composition comprising: a) a bitumen feedstock; b) a polyolefin; and c) about 5% to 60% of a carbon footprint reduction material selected from the group consisting of kraft lignin, fibrous material, bitumen recovered from recycled asphalt shingles (RAS) or recycled asphalt pavements (RAP), recycled tire rubber (RTR), and combinations thereof, based on the total weight of the roofing bitumen composition. Claim 2 In claim 1, the bitumen feedstock is a packaging grade bitumen, a looping bitumen composition. Claim 3 A roofing bitumen composition according to claim 1, wherein the polyolefin is a low molecular weight polyolefin selected from the group consisting of polyethylene homopolymer, oxidized polyethylene homopolymer, polypropylene homopolymer, maleated polyethylene, maleated polypropylene, ethylene vinyl acetate copolymer, ethylene acrylic acid copolymer, Fischer-Tropsch wax, thermally decomposed wax, and combinations thereof. Claim 4 A roofing bitumen composition according to claim 3, comprising a low molecular weight polyolefin in a weight percentage of 1% to 5% based on the total weight of the roofing bitumen composition. Claim 5 In paragraph 3, the oxidized polyethylene homopolymer is a looping bitumen composition in which the oxidized high-density polyethylene homopolymer is an oxidized high-density polyethylene homopolymer. Claim 6 A roofing bitumen composition according to claim 5, comprising 1% to 5% of an oxidized high-density polyethylene homopolymer based on the total weight of the roofing bitumen composition. Claim 7 A roofing bitumen composition according to claim 3, comprising 1% to 5% maleated polypropylene based on the total weight of the roofing bitumen composition. Claim 8 A roofing bitumen composition according to claim 1, wherein the softening point of the roofing bitumen composition is 88°C to about 160°C as determined according to method ASTM D36. Claim 9 A roofing bitumen composition according to claim 8, wherein the softening point of the roofing bitumen composition is 90°C to about 100°C as determined according to method ASTM D36. Claim 10 A roofing bitumen composition according to claim 1, wherein the penetration of the roofing bitumen composition at 25°C is greater than 15 mm as determined according to method ASTM D5. Claim 11 A roofing single composition comprising: a) a bitumen feedstock; b) a low molecular weight polyolefin; and c) a carbon footprint reduction material or materials; and d) a filler, wherein components a) to c) account for up to 30 weight percent based on the total weight of the roofing single composition, and component d) accounts for up to 70 weight percent based on the total weight of the roofing single composition. Claim 12 A method for producing a roofing single composition of claim 11, comprising the step of mixing a carbon footprint reduction material selected from the group consisting of a paving-grade bitumen feedstock, a low MW polyolefin, and kraft lignin, recycled fibrous material, bitumen recovered from recycled single (RAS) and / or recycled asphalt pavement (RAP), recycled tire rubber (RTR), and combinations thereof, at an elevated temperature to form a bitumen composition; wherein the carbon footprint required to produce the bitumen composition is reduced by more than 5% compared to the carbon footprint required to produce oxidized bitumen from the roof-grade bitumen; and then a filler is combined with the bitumen composition to form a roofing single composition. Claim 13 A method according to claim 12, wherein the bitumen composition is prepared by adding a carbon footprint reducing material and a low MW polyolefin to a molten base at about 140°C to about 200°C, and the mixture can be blended for 1 to 4 hours at about 200 to about 20,000 rpm and optionally about 3,000 RPM using a high-shear or low-shear mixer.

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