Method for enhancing the carbon product performance in elastomers

Abstract

This invention provides a method for enhancing the performance of carbon products in elastomers. [Solution] A method for processing particulate carbon comprises combining pyrolysis carbon with water to form a mixture to form an initial slurry having 1 to 35% by weight of solids, and grinding the pyrolysis carbon to form a grinding slurry containing wet-ground regenerated carbon and water; the volume-weighted particle size distribution of the wet-ground regenerated carbon, measured via scanning electron microscopy, satisfies at least one of the following conditions: D50 is 2700 nm or less, and particles having a particle size greater than 5 microns account for 15% or less.

Description

[Technical Field]

[0001] The present invention relates to an improved method for processing recycled carbon black. [Background technology]

[0002] Frequently, used car tires are processed and reused in a wide range of end-uses, from playground equipment to concrete. However, to reduce the amount of new material required to manufacture new tires, it is desirable to recycle the components of tires to obtain materials that can be combined with the initial-use materials. Tires can be processed by pyrolysis, i.e., heating in the absence of oxygen, which converts the elastomers into lower molecular weight hydrocarbons and recovers carbonaceous powder. However, the resulting powder is not equivalent to carbon black as a rubber reinforcing agent. Even when combined with carbon black, it results in inferior fatigue performance and other mechanical properties. Therefore, to reduce the environmental impact of waste tires, it is desirable to improve the performance of particulate carbon recovered by pyrolysis from tires and other sources. [Overview of the Initiative]

[0003] As used herein, "char" refers to the solid material resulting from the thermal decomposition of rubber products.

[0004] As used herein, “dried, pulverized, and recycled carbon” refers to pyrolysis carbon that is substantially free of visible impurities, pulverized without the use of water, and optionally pelletized.

[0005] As used herein, "carbon black" means carbon-containing particles of the element carbon obtained by partial combustion or thermal decomposition of hydrocarbons, which are aggregated into strong aggregates and weak aggregates.

[0006] As used herein, “raw material recycled carbon” is a solid material resulting from the thermal decomposition of rubber products containing any amount of carbonaceous particulate filler, including but not limited to carbon black.

[0007] As used herein, “processed recycled carbon” means raw recycled carbon that has been treated to remove at least one visible impurity, such as fabric or wire.

[0008] As used herein, “pyrolysis carbon” includes char, raw material recycled carbon, processed recycled carbon, and dried and ground recycled carbon.

[0009] As used herein, “pulverized recycled carbon” or “pulverized rC” refers to pyrolysis carbon that has been pulverized and is substantially free of visible impurities.

[0010] As used herein, “recycled carbon” refers to raw recycled carbon that has been processed to remove visible impurities and optionally further ground. Therefore, processed recycled carbon, ground recycled carbon, dry ground recycled carbon, and wet ground recycled carbon all fall under the definition of recycled carbon.

[0011] As used herein, “wet-ground recycled carbon” is pyrolysis carbon that is substantially free of visible impurities and is ground in the presence of at least 50% by weight, preferably 65–99%, of water based on the total weight of the material being ground.

[0012] In one embodiment, a method for processing particulate carbon includes combining pyrolysis carbon with water to form a mixture to form an initial slurry having a solid content of 1 to 35% by weight, and grinding the pyrolysis carbon to form a pulverized slurry of wet-pulverized regenerated carbon and water. The volume-weighted particle size distribution curve of the wet-pulverized regenerated carbon, measured via scanning electron microscopy, satisfies at least one of the following conditions: D50 is 2700 nm or less, and particles having a particle size greater than 5 microns account for 15% or less, for example, D50 of 1000 nm to 2700 nm or 1200 nm to 2500 nm. Alternatively, the wet-pulverized regenerated carbon may have a D75 of 2500 nm to 3300 nm, for example, 1700 nm to 3000 nm. Alternatively, 3% to 10% of the wet-pulverized regenerated carbon particles may have a particle size greater than 5 microns. Alternatively, 65% or less of the particles, for example, 25% to 60%, may have a particle size greater than 2 microns.

[0013] This method may further include removing visible contaminants from an initial slurry that may optionally have a solid content of up to 25% by weight. Combining may further include forming an initial slurry by combining at least one auxiliary filler with water. The auxiliary filler may be selected from the group consisting of carbon black, silicon-treated carbon black, silica-coated carbon black, precipitated silica, hydrothermal carbon, artificial polysaccharides, graphene, graphene oxide, reduced graphene oxide, nanocellulose, lignin, clay, nanoclay, metal oxides, metal carbonates, single-walled carbon nanotubes, multi-walled carbon nanotubes, carbon nanostructures, carbon black-coated particles, and mixtures of two or more of these. Grinding may be carried out using at least one apparatus selected from cutter mixers, ball mills, media mills, homogenizers, attritors, horizontal bead mills, rotor stator mills, and colloid mills.

[0014] The method may further include adding at least one additional filler selected from carbon black, silicon-treated carbon black, silica-coated carbon black, coated carbon black particles, and precipitated silica to the pulverized slurry to adjust the solid content of the resulting wet blended carbon mixture to 25-70% by weight. Addition may include adding an aqueous slurry containing at least one additional filler, adding additional water to the pulverized slurry, or both. The method may further include pelletizing the wet blended carbon mixture to form pellets, spray-drying the wet blended carbon mixture, and optionally drying the pellets.

[0015] The water may be a continuous flow of water, the grinding slurry may be a continuous flow of grinding slurry, and the combination may include weighing pyrolysis carbon into a continuous flow of water. The combination may further include weighing at least one auxiliary packing agent into a continuous flow of water. The auxiliary packing agent may be selected from the group consisting of carbon black, silicon-treated carbon black, silica-coated carbon black, precipitated silica, hydrothermal carbon, artificial polysaccharides, graphene, graphene oxide, reduced graphene oxide, nanocellulose, lignin, clay, nanoclay, metal oxides, metal carbonates, single-walled carbon nanotubes, multi-walled carbon nanotubes, carbon nanostructures, carbon black-coated particles, and mixtures of two or more of these. The method may further include weighing at least one additional packing agent selected from carbon black, silicon-treated carbon black, silica-coated carbon black, carbon black-coated particles, and precipitated silica into a continuous flow of grinding slurry to adjust the solid content of the resulting wet blend carbon mixture continuous flow to 25-70% by weight or 1-25% by weight. Measuring may include measuring an aqueous slurry of additional packing material into a continuous flow of the pulverized slurry, measuring additional water into a continuous flow of the pulverized slurry, or both.

[0016] In any of these embodiments, the method may further include, for example, pelletizing the wet blended carbon mixture to form pellets, or granulating the wet blended carbon mixture by spray drying. The pellets may be dried. The pulverized slurry can be spray dried or its solid components can be granulated by other means. For example, the pulverized slurry can be dehydrated to a predetermined moisture level and then pelletized.

[0017] In another embodiment, the present invention includes pellets manufactured using any combination or subcombination of the method steps described above.

[0018] In another embodiment, the particulate filler contains at least 10% by weight (dry basis), for example, 10-100% by weight, 10-90% by weight, 15-80% by weight, 20-60% by weight, or 30-50% by weight of recycled carbon. The volume-weighted particle size distribution of the recycled carbon, as measured by scanning electron microscopy, satisfies at least one of the following conditions: D50 is 2700 nm or less, and particles having a particle size greater than 5 microns constitute 15% or less. For example, the recycled carbon may have a D50 of 1000 nm to 2700 nm or 1200 nm to 2500 nm. Alternatively, the recycled carbon may further have a D75 of 2500 nm to 3300 nm, for example, 1700 nm to 3000 nm. Alternatively, 3% to 10% of the recycled carbon may have a particle size greater than 5 microns. Alternatively, or furthermore, 65% or less of the recycled carbon, for example 25% to 60%, may have a particle size greater than 2 microns.

[0019] In any of these embodiments, the particulate filler may further include one or more auxiliary fillers selected from carbon black, silicon-treated carbon black, silica-coated carbon black, precipitated silica, hydrothermal carbon, artificial polysaccharides, graphene, graphene oxide, reduced graphene oxide, nanocellulose, lignin, clay, nanoclay, metal oxides, metal carbonates, single-walled carbon nanotubes, multi-walled carbon nanotubes, carbon nanostructures, and carbon black-coated particles. The particulate filler may have a water content of 15 to 80% by weight, for example, 40 to 60% by weight.

[0020] The particulate filler may be in the form of pellets. The pellets may contain 15-80% water, for example, 40-60% water, or 3% or less water, and / or may substantially consist of particulate filler, any water, and any binder. The pellets may contain particulate filler according to any of these embodiments, and at least one additional filler selected from carbon black, silicon-treated carbon black, silica-coated carbon black, carbon black-coated particles, and precipitated silica.

[0021] In any of these embodiments, the recycled carbon may be wet-ground recycled carbon.

[0022] In another embodiment, the elastomer composite comprises a mixture of an elastomer and a particulate filler of 30 to 90 phr, such as 30 to 70 phr, 35 to 60 phr, or 40 to 55 phr. The particulate filler comprises at least 10 wt% recycled carbon, such as 10 to 100 wt%, 10 to 90 wt%, 15 to 80 wt%, 20 to 60 wt%, or 30 to 50 wt% recycled carbon. The recycled carbon, in particulate form, i.e., before being mixed with the elastomer, satisfies at least one of the following: the D50 (volume weighted), measured by scanning electron microscopy inspection, is 2700 nm or less, and the particles having a particle size of more than 5 microns are 15% (volume weighted) or less. For example, the recycled carbon may have a D50 of 1000 nm to 2700 nm or 1200 nm to 2500 nm. Alternatively, or additionally, the recycled carbon may have a D75 of 2500 nm to 3300 nm, such as 1700 nm to 3000 nm. Alternatively, or additionally, 3% to 10% of the recycled carbon may have a particle size of more than 5 microns. Alternatively, or additionally, 65% or less, such as 25% to 60%, of the recycled carbon may have a particle size of more than 2 microns. The particulate filler may further comprise one or more of carbon black, silica-treated carbon black, silica-coated carbon black, precipitated silica, hydrothermal carbon, artificial polysaccharides, graphene, graphene oxide, reduced graphene oxide, nanocellulose, lignin, clay, nanoclay, metal oxides, metal carbonates, single-walled carbon nanotubes, multi-walled carbon nanotubes, carbon nanostructures, and carbon black-coated particles.

[0023] [[ID=|3]] In any of these embodiments, the elastomer may be selected from natural rubber, functionalized natural rubber, styrene-butadiene rubber, functionalized styrene-butadiene rubber, polybutadiene rubber, functionalized polybutadiene rubber, polyisoprene rubber, ethylene-propylene copolymer, isobutylene-based rubber, polychloroprene rubber, nitrile rubber, hydrogenated nitrile rubber, polysulfide rubber, polyacrylate elastomer, fluoroelastomer, perfluoroelastomer, and blends thereof.

[0024] In any of these embodiments, the elastomer composite may exhibit a macrodispersion of up to 0.03x + 4.4, for example, 0.03x to 0.03x + 4.4, where x is the proportion of recycled carbon in the particulate filler, and macrodispersion is the area proportion of undispersed filler particles larger than 5 μm, as determined by optical microscopy in the reflection mode. When the particulate filler is recycled carbon and carbon black, the elastomer composite may exhibit a macrodispersion of up to 1.9ln(x) + 1.2, for example, 1.9ln(x) - 3.2 to 1.9ln(x) + 0.2.

[0025] In any of these embodiments, the recycled carbon may be wet-ground recycled carbon.

[0026] In any of these embodiments, the elastomer composite may be a vulcanized elastomer composite. The tire tread may include a vulcanized mixture of the elastomer composite and the curing agent package. Alternatively, the article may further include a vulcanized mixture of the elastomer composite and the curing agent package. The article may be incorporated into a pneumatic tire, a non-pneumatic tire, or a solid tire. The article may be selected from tire treads, undertreads, inner liners, sidewalls, sidewall inserts, wire skims, and cushion gums for retreaded tires. Articles may be selected from hoses, linings, liners, seals, gaskets, vibration damping articles, trucks, track pads for truck propulsion vehicle systems, engine mounts, seismic stabilization devices, screens for mining equipment, linings for mining equipment, conveyor belts, chute liners, slurry pump liners, mud pump impellers, valve seats, valve bodies, piston hubs, piston rods, plungers, slurry mixing impellers and slurry pump impellers, crusher liners, cyclones and liquid cyclones, expansion joints, linings for dredging pumps and outboard motor pumps for marine equipment, shaft seals for ships, oil, space, and other applications, propeller shafts, pipe linings, engine mounts, bushings, fillers, windshield wipers, automotive parts, seals, gaskets, housings, wheel elements, and track elements.

[0027] Alternatively, or further, the vulcanizate of a mixture of an elastomeric composite having a curing agent package has fatigue properties equal to or at least 90% of the vulcanizate produced via the same process and same composition, except having ASTM N550 carbon black instead of recycled carbon. The vulcanizate may exhibit a macrodispersion of up to 0.03x + 4.4, e.g., 0.03x to 0.03x + 4.4, where x is the proportion of recycled carbon in the particulate filler, and the macrodispersion is the area fraction of undispersed filler particles greater than 5 μm determined by optical microscopy in reflection mode. When the particulate filler is recycled carbon and carbon black, the vulcanizate may exhibit a macrodispersion of up to 1.9 ln(x) + 0.2, e.g., 1.9 ln(x) - 3.2 to 1.9 ln(x) + 0.2.

[0028] In another embodiment, the elastomer composite comprises a mixture of an elastomer and a particulate filler of 30 to 90 phr. In a particular embodiment, the particulate filler contains at least 10 wt% recycled carbon, and the elastomer composite exhibits a macrodispersion of up to 0.03x + 4.4, e.g., 0.03x to 0.03x + 4.4, where x is the proportion of recycled carbon in the particulate filler, and macrodispersion is the area percentage of undispersed filler particles greater than 5 μm, as determined by optical microscopy in reflection mode. If the particulate filler contains at least 10 wt% (dry basis) recycled carbon together with the remainder carbon black, the macrodispersion is up to 1.9ln(x) + 1.2, e.g., 1.9ln(x) - 3.2 to 1.9ln(x) + 0.2. In any of these embodiments, the elastomer composite may be vulcanized, and / or the recycled carbon may be wet-ground recycled carbon. Recycled carbon may satisfy at least one of the following conditions, measured by scanning electron microscopy: a D50 (volume weighted) of 2700 nm or less, and 15% (volume weighted) or less of particles having a particle size greater than 5 microns. For example, recycled carbon may have a D50 of 1000 nm to 2700 nm or 1200 nm to 2500 nm. Alternatively, recycled carbon may have a D75 of 2500 nm to 3300 nm, for example, 1700 nm to 3000 nm. Alternatively, 3% to 10% of recycled carbon may have a particle size greater than 5 microns. Alternatively, 65% or less of recycled carbon, for example, 25% to 60%, may have a particle size greater than 2 microns.

[0029] Both the general description above and the detailed description below are illustrative and descriptive, and it should be understood that they are intended to provide further explanation of the invention as claimed. [Brief explanation of the drawing]

[0030] The present invention will be described with reference to some of the figures in the drawings.

[0031] [Figure 1]Figure 1 shows the particle size distribution of raw char (dotted line, CBP Cyprus) that has been jet-ground (dashed line) or processed according to an exemplary embodiment (solid line). [Figure 2] Figure 2 shows the particle size distribution of samples of char (dashed line - CBP Cyprus, dashed line - Polimix Ambiental) and Polimix 300 processed recycled carbon (solid line) processed according to exemplary embodiments. [Figure 3] Figure 3 shows the particle size distribution of jet-milled samples of char (dashed line - CBP Cyprus, dashed line - Polimix Ambiental) and Polimix 300 processed recycled carbon (solid line). [Figure 4] Figure 4 shows undispersed, strongly aggregated particles with a diameter greater than 5 microns in the filler-filled elastomer composite as a function of the proportion of recycled carbon in the filler. Triangles indicate comparative samples, and circles indicate samples prepared according to embodiments of the present invention. The sample with 26.9% recycled carbon uses a blend of recycled carbon and precipitated silica as the filler, with the remaining blend containing carbon black. [Modes for carrying out the invention]

[0032] In one embodiment, a method for processing particulate carbon includes combining pyrolysis carbon with water to form a mixture to form an initial slurry having a solid content of 1 to 35% by weight, and pulverizing the pyrolysis carbon to form a pulverized slurry of wet pulverized regenerated carbon and water. The volume-weighted particle size distribution of the pulverized slurry, measured via scanning electron microscopy, satisfies at least one of the following conditions: D50 is 2700 nm or less, and particles having a particle size greater than 5 microns constitute 15% or less, for example, D50 of 1000 nm to 2700 nm or 1200 nm to 2500 nm. Alternatively, the pulverized slurry may have a D75 of 2500 nm to 3300 nm, for example, 1700 nm to 3000 nm. Alternatively, 3% to 10% of the particles may have a particle size greater than 5 microns. Alternatively, 65% or less of the particles, for example, 25% to 60%, may have a particle size greater than 2 microns.

[0033] Pyrolysis carbon may include one or more raw material recycled carbon, processed recycled carbon, and dried-ground recycled carbon. Preferably, pyrolysis carbon is derived from rubber products originally manufactured from carbon black. Pyrolysis may be carried out by any method known to those skilled in the art. Exemplary methods include, but are not limited to, those found in U.S. Patent No. 8,350,105 and U.S. Patent Application Publication No. 2018 / 0320082, the entire contents of both of which are incorporated herein by reference. Pyrolysis carbon is combined with water to form an initial slurry having a solids content concentration of 1 to 35% by weight, e.g., 5 to 30% by weight, 7 to 25% by weight, 10 to 20% by weight, or 15 to 25% by weight. The concentration is preferably adjusted to the concentration required in downstream processes, including grinding and optional pelletizing.

[0034] The pyrolysis carbon may be treated to remove visible contaminants. For example, magnetic separation techniques known to those skilled in the art may be used to remove wires and other visible metallic contaminants. Filters or screens may be used to remove fabrics and other non-magnetic visible contaminants. The pyrolysis carbon may be treated before being combined with water to form an initial slurry, and / or the initial slurry may be treated to remove visible contaminants.

[0035] Alternatively, the pyrolysis carbon may be treated to remove ash, for example, by washing the pyrolysis carbon with acid or by using an ion exchanger. Exemplary methods are described in U.S. Patent Application Publication No. 2015,0307714, Chinese Patent Application Publication No. 101,357,758, and International Publication No. 2021 / 005124, the entire contents of which are incorporated herein by reference.

[0036] In some embodiments, the method is continuous. In these embodiments, pyrolysis carbon is continuously metered into a continuous stream of water to form a continuous stream of initial slurry. The continuous stream of initial slurry may be treated using techniques known to those skilled in the art to remove any visible contaminants.

[0037] The initial slurry is pulverized following any processing. Any technique known to those skilled in the art for pulverizing or grinding the fine particle slurry may be used. Exemplary apparatuses include cutter mixers, ball mills, media mills, homogenizers, attritors, horizontal bead mills, rotor stator mills, colloid mills, and other apparatus known to those skilled in the art. Pulverization can convert the pyrolysis carbon into wet pulverized regenerated carbon having a volume-weighted particle size distribution, measured via scanning electron microscopy, characterized by satisfying one or both of the following: D50 is 2700 nm or less, and particles having a particle size greater than 5 microns are 15% or less. For example, D50 may be 1000 nm to 2700 nm or 1200 nm to 2500 nm. Alternatively, the pulverized slurry may have a D75 of 2500 nm to 3300 nm, for example, 1700 nm to 3000 nm. Alternatively, 3% to 10% of the particles have a particle size greater than 5 microns. Alternatively, or furthermore, less than 65% of the particles, for example, 25% to 60%, may have a particle size greater than 2 microns. Without being bound by any particular theory, it is believed that the performance of vulcanized elastomer composites produced using dried, pulverized, recycled carbon is degraded due to the presence of large, weak aggregates that are hardly dispersed in the elastomer. The method provided herein more effectively reduces the size of weak aggregates, thereby improving the dispersion of fillers in the elastomer matrix and improving the performance of the resulting vulcanized elastomer composite. The improved mechanical properties may be reflected in fatigue performance, tensile performance, tear performance, slash / tip performance, or other properties typically measured on elastomer composites.

[0038] The particle size distribution can be measured using any suitable method known to those skilled in the art, such as laser diffraction. Preferably, the particle size distribution is measured using scanning electron microscopy, for example, the scanning electron microscopy method described in more detail in the examples. Briefly, the particles are dispersed slowly in water at a concentration of 0.2 wt% with 600 ppm of Triton® X 100 surfactant, and then stirred for 24 hours. The dispersion is diluted to a suitable concentration, filtered onto a membrane filter, dried, sputter-coated with a conductive material, and imaged. Imaging is performed at high and low magnifications to provide sufficient resolution to capture small particles while efficiently imaging large particles. The images are processed to minimize non-uniform image background, enhance particle contrast, and reduce image noise while preserving particle edges. The particle size distribution is measured at each magnification, with Dcirc = 2 (area of ​​the projected image / π) on at least 50,000, typically 50,000 to 200,000 particles. 1 / 2 Determined by measuring

[0039] The initial slurry may contain one or more auxiliary fillers, which may also be beneficial from being co-ground with pyrolysis carbon. Any particulate fillers that provide reinforcement or other beneficial properties to the rubber may be used. Exemplary auxiliary fillers include carbon black, silicon-treated carbon black, silica-coated carbon black, precipitated silica, hydrothermal carbon (i.e., carbonaceous materials produced by the hydrothermal carbonization of lignin or other biomass, as described, for example, in U.S. Patent No. 10,428,218 or No. 10,035,957 (both of which are incorporated herein by reference)), and those described in U.S. Patent Publication No. 2020 / 181370 and No. 2020 / 190270 (both of which are incorporated herein by reference), etc. This includes, but is not limited to, artificial polysaccharides, as well as carbon nanostructures such as graphene, graphene oxide, reduced graphene oxide, nanocellulose, lignin, clay, nanoclay, metal oxides, metal carbonates, single-walled carbon nanotubes, multi-walled carbon nanotubes, and those described in U.S. Patent Application Publication No. 2014 / 0093728 (the entire content of which is incorporated herein by reference), and carbon black coated particles such as those described in U.S. Patent No. 10,519,298 (the entire content of which is incorporated herein by reference). Preferably, any visible impurities are removed from the pyrolytic carbon, either in a dry or slurry state, before combining the pyrolytic carbon with one or more auxiliary fillers. The auxiliary fillers can be combined with the pyrolytic carbon in a dry state, or added separately to water before, after, or simultaneously with the pyrolytic carbon to form an initial slurry. To avoid separation that may occur in the dry mixture of pyrolytic carbon and auxiliary fillers, the auxiliary fillers are preferably added directly to the water or initial slurry, separately from the pyrolytic carbon. The ratio of pyrolytic carbon to auxiliary filler in the initial slurry can be any range suitable for the desired end application and for maintaining an acceptable viscosity of the initial slurry so that it can be pulverized.In a continuous process, auxiliary fillers may be continuously metered into the initial slurry or into a continuous flow of water, either as a powder or as an aqueous slurry of the auxiliary fillers (or two or more slurries if two or more auxiliary fillers are used). Those skilled in the art will recognize that the appropriate concentration for grinding depends on the properties of the auxiliary fillers. For example, carbon nanotubes increase slurry viscosity at very low concentrations, while higher concentrations of precipitated silica may not dramatically increase viscosity.

[0040] Additional fillers may also be added to the pulverized slurry. Such additional fillers preferably do not require additional pulverization. Exemplary additional fillers for addition to the pulverized slurry include, but are not limited to, carbon black, silica-coated carbon black, silica-treated carbon black, precipitated silica, carbon black-coated particles such as those described in U.S. Patent No. 10,519,298, and mixtures of two or more of these. Depending on the solid content concentration of the pulverized slurry, it may also be desirable to add water along with the additional fillers to adjust the solid content concentration of the resulting wet-blended carbon mixture. Alternatively, the additional fillers may be added to the pulverized slurry as an aqueous slurry. In a continuous process, the additional fillers may be continuously metered into the initial slurry or into a continuous stream of water, either as a powder or as an aqueous slurry of the additional fillers. The total filler concentration may be such that the wet-blended carbon mixture can be easily formed into pellets or spray-dried. To form pellets, additional fillers and optional water added to the pulverized slurry can result in a solid content of 25–70% by weight of the resulting wet blend carbon mixture, for example, 30–65% by weight, 35–60% by weight, or 40–50% by weight. For spray drying, additional fillers and optional water added to the pulverized slurry can result in a solid content of 1–30% by weight of the resulting wet blend carbon mixture, for example, 1–10% by weight, 5–15% by weight, or 8–25% by weight. For spray drying, it may be desirable to omit the additional fillers. Those skilled in the art will know how to adjust the total filler concentration in conventional apparatus to prepare the desired pellets or the optimal concentration for spray drying. The fillers added to the pulverized slurry may be the same as, or different from, any fillers added to the initial slurry.

[0041] The carbon black for use in any of the embodiments of this specification includes, but is not limited to, carbon black of ASTM N100 series to N900 series, for example, carbon black of N100 series, N200 series, N300 series, N500 series, N600 series, N700 series, N800 series, or N900 series. Carbon black sold under the trademarks of Regal (trademark), Black Pearls (trademark), Spheron (trademark), Sterling (trademark), and Vulcan (trademark) available from Cabot Corporation, carbon black sold under the trademarks of Raven (trademark), Statex (trademark), Furnex (trademark), and Neotex (trademark) as well as carbon black sold in CD and HV lines available from Birla Carbon (Columbian Chemicals), carbon black sold under the trademarks of Corax (trademark), Durax (trademark), Ecorax (trademark), and Purex (trademark) as well as carbon black sold in CK line and other carbon black available from Orion Engineered Carbons, and other fillers suitable for use in rubber or tire applications can also be utilized for use with various embodiments. The carbon black can be chemically functionalized. Suitable chemically functionalized carbon blacks include those disclosed in WO 96 / 18688 and US Patent Application Publication No. 2013 / 0165560, the disclosures of which are incorporated herein by reference.

[0042] The carbon black has at least about 15 m 2 / g, for example about 15 m 2 / g to about 240 m 2 / g, for example about 35 m <{ 2 / g to about 230 m 2 / g, about 50 m 2 / g to about 200 m 2 / g, about 60 m 2 / g to about 180 m 2 / g, about 100 m2 From / g to approximately 200m 2 It can have a statistical thickness specific surface area of ​​ / g (STSA, ASTM standard D6556).

[0043] Carbon black having any of the above specific surface areas may further have structures with oil absorption rates of approximately 50 to approximately 115 mL / 100g, for example, approximately 65 to approximately 75 mL / 100g, approximately 60 to approximately 95 mL / 100g, approximately 75 to approximately 85 mL / 100g, approximately 85 to approximately 95 mL / 100g, approximately 95 to approximately 105 mL / 100g, or approximately 105 to approximately 115 mL / 100g, as determined by the oil absorption rate of compressed carbon black (COAN, ASTM D3493).

[0044] A mixture of any of these carbon blacks can be used.

[0045] The materials described herein as silicon-treated carbon black are not limited to coated or otherwise modified carbon black strong aggregates. They may also be different types of strong aggregates having two phases. One phase is carbon, which still exists as graphite microcrystalline and / or amorphous carbon, while the second phase is silica (and possibly other silicon-containing species). Thus, the silicon-containing species phase of silicon-treated carbon black is an inherent part of the strong aggregate and is distributed throughout at least a portion of the strong aggregate. Various silicon-treated blacks are available from Cabot Corporation under the name Ecoblack® and are described in detail in U.S. Patent No. 6,028,137. It should be understood that multilayer strong aggregates consist of pre-formed single-layer carbon black strong aggregates having silicon-containing species deposited on their surfaces, and are quite different from the silica-coated carbon black described above. Such carbon black may be surface-treated to arrange silica functionality on the surface of the carbon black aggregate, for example, as described in U.S. Patent No. 6,929,783, No. 6,541,113, and No. 5,679,728.

[0046] In any embodiment of this specification, suitable precipitated silica for use includes both highly dispersible (HDS) granulated and non-HDS precipitated silica. The precipitated silica may be chemically treated to include functional groups such as coupling agents bonded (adhered (e.g., chemically attached) or adsorbed (e.g., absorbed)) to the silica surface. Examples of suitable grades of HDS include Perkasil® GT 3000GRAN silica from WR Grace & Co, Ultrasil® 7000 silica from Evonik Industries, Zeosil® 1165 MP and 1115 MP silica from Solvay SA, Hi-Sil® EZ 160G silica from PPG Industries Inc., and Zeopol® 8741 or 8745 silica from Evonik Industries. Examples of suitable grades of conventional (non-HDS) precipitated silica include Perkasil® KS 408 silica from WR Grace & Co., Zeosil® 175GR silica from Solvay SA, Ultrasil® VN3 silica from Evonik Industries, and Hi-Sil® 243 silica from PPG Industries, Inc. Suitable grades of hydrophobic precipitated silica include Agilon® 400, 454, or 458 silica from PPG Industries, Inc., and Coupsil® silica from Evonik Industries, such as Coupsil® 6109 silica.

[0047] A wet-blended carbon mixture can be densified, for example, by granulation or pelletization. Any densification or pelletization method known to those skilled in the art can be used. For example, the method described in Glaxner's U.S. Patent No. 2,065,371 can be used. Generally, the wet-blended carbon mixture can be formed into beads, which can then be optionally dried to reduce the water content to a maximum of 1% to form blended carbon pellets. In addition to the water already present in the wet-blended carbon mixture, a wide variety of binding additives are known to be useful in the wet pelletization process to further improve the handling properties of the resulting pellets. Examples of such additives include, but are not limited to, hygroscopic organic liquids such as ethylene glycol, carbohydrates (e.g., sugars, molasses, soluble starch, sugars, lignin derivatives), rosin, sulfonate and sulfate anionic surfactants, aliphatic amine ethoxylate nonionic surfactants, sodium lignin sulfonate, silane, sucrose, alkyl succinimide, alkylated succinate esters, and polyethylene oxide-co-polydimethylsiloxane surfactants. Alternatively, the pellets do not need to be dried and may be used in a wet state, in which case a binder is not required. For example, wet pellets may have a moisture content of 15-80% by weight, for example, 40-60% by weight.

[0048] The particulate filler obtained in the formation of wet pellets or dry pellets or several other forms (e.g., slurry before pelletization or other drying methods) contains, on a dry basis, 2 to 100% by weight, for example, 5 to 98% by weight or 8 to 90% by weight, 10 to 60% by weight, 15 to 50% by weight, 10 to 100% by weight, 15 to 60% by weight, 10 to 90% by weight, 15 to 80% by weight, 20 to 60% by weight, or 30 to 50% by weight, or 20 to 50% by weight of recycled carbon, preferably wet-ground recycled carbon. The remainder consists of one or more fillers other than recycled carbon, such as the additional and / or auxiliary fillers listed above, e.g., carbon black, silicon-treated carbon black, silica-coated carbon black, precipitated silica, hydrothermal carbon, artificial polysaccharides, graphene, graphene oxide, reduced graphene oxide, nanocellulose, lignin, clay, nanoclay, metal oxides, metal carbonates, single-walled carbon nanotubes, multi-walled carbon nanotubes, carbon nanostructures, and carbon black-coated particles. The volume-weighted particle size distribution of the recycled carbon and / or overall particulate filler (i.e., a mixture of recycled carbon and other fillers), as measured by scanning electron microscopy, may satisfy at least one of the following conditions: D50 is 2700 nm or less, and particles with a particle size greater than 5 microns constitute 15% or less, for example, a D50 of 1000 nm to 2700 nm or 1200 nm to 2500 nm. Alternatively, the recycled carbon and / or overall particulate filler may have a D75 of 2500 nm to 3300 nm, for example, 1700 nm to 3000 nm. Alternatively, 3% to 10% of the recycled carbon and / or overall particulate filler may have a particle size greater than 5 microns. Alternatively, 65% or less of the recycled carbon and / or overall particulate filler, for example, 25% to 60%, may have a particle size greater than 2 microns. As described above, the pellets may also contain a binder. In all these embodiments, the recycled carbon is preferably wet-ground recycled carbon.

[0049] Alternatively, the wet-blended carbon mixture may be spray-dried using any spray-drying apparatus known to those skilled in the art. The resulting spray-dried particles may contain, on a dry basis, 2-100% recycled carbon, e.g., 5-98% or 8-90% by weight, 10-60% by weight, 15-50% by weight, 10-100% by weight, 15-60% by weight, 10-90% by weight, 15-80% by weight, 20-60% by weight, or 30-50% by weight, or 20-50% by weight recycled carbon, preferably wet-ground recycled carbon, and 0-98% by weight, e.g., 2%-95% by weight, e.g., 10%-92% by weight, 40-90% by weight, or 50%-80% or 85% by weight carbon black, silica-coated carbon black, silica-treated carbon black, precipitated silica, or carbon black-coated particles. The materials may also include additional fillers selected from mixtures of two or more of these, and one or more auxiliary fillers selected from carbon black, silicon-treated carbon black, silica-coated carbon black, precipitated silica, hydrothermal carbon, artificial polysaccharides, graphene, graphene oxide, reduced graphene oxide, nanocellulose, lignin, clay, nanoclay, metal oxides, metal carbonates, single-walled carbon nanotubes, multi-walled carbon nanotubes, carbon nanostructures, and carbon black-coated particles in amounts of 0-98% by weight, e.g., 2-95%, e.g., 10-92%, 40-90%, or 50-80% or 85% by weight.

[0050] Wet pellets, dry pellets, and / or spray-dried particles according to various embodiments of this specification can be combined with elastomers to form elastomer composites. The resulting elastomer composites may contain particulate fillers of 30-90 phr, for example, particulate fillers of 30-70, 35-60, or 40-55 phr. The particulate fillers may contain 2-100% by weight of recycled carbon, for example, 5-98% by weight or 8-90% by weight, preferably 10-100% by weight, 10-90% by weight, 15-80% by weight, 20-60% by weight, or 30-50% by weight of recycled carbon, preferably wet-ground recycled carbon, and exhibit a volume-weighted particle size distribution, as measured by scanning electron microscopy, that satisfies either or both of the following conditions: D50 is 2700 nm or less, and particles having a particle size greater than 5 microns constitute 15% or less. For example, either recycled carbon or the overall particulate filler, or both, may exhibit a D50 of 1000 nm to 2700 nm or 1200 nm to 2500 nm. Alternatively, the recycled carbon, the overall particulate filler, or both may have a D75 of 2500 nm to 3300 nm, for example, 1700 nm to 3000 nm. Alternatively, 3% to 10% of the recycled carbon, the particulate filler, or both may have a particle size greater than 5 microns. Alternatively, 65% or less of the recycled carbon or the overall particulate filler, for example, 25% to 60%, may have a particle size greater than 2 microns. In all of these embodiments, the recycled carbon is preferably wet-ground recycled carbon. Both natural rubber and synthetic elastomers of any grade may be used. Blends of elastomers may also be used. For example, wet pellets, dry pellets and / or spray-dried particles may be combined with an elastomer to form a masterbatch, and then the masterbatch may be combined with additional elastomers of the same or different composition. Alternatively, two or more elastomers may be blended before mixing with the pellets. Alternatively, the elastomer composite may also contain one or more fillers, including any of the particulate fillers listed elsewhere in this specification, except recycled carbon, and any other fillers known to those skilled in the art for use in elastomer composites.Such fillers may be present in a mixture with pulverized recycled carbon or in pellets, or may be added to the elastomer separately from any of the wet pellets, dry pellets, and / or spray-dried particles according to the various embodiments of this specification.

[0051] Elastomer composites can exhibit a macrodispersion of up to 0.03x+4.4, for example, 0.03x~0.03x+4.4, especially when the filler contains 10-100% by weight, e.g., 10-90%, 15-80%, 20-60%, or 30-50% by weight of recycled carbon, preferably wet-ground recycled carbon, where x is the percentage of wet-ground recycled carbon in the fine particle filler, and macrodispersion is the area percentage of undispersed filler particles (% undispersed area) larger than 5 μm, determined by optical microscopy in reflection mode after the sample has been cut to reveal its interior. Preferably, macrodispersion is measured on vulcanized elastomer composites. With respect to macrodispersion, the term “particles” is intended to represent the area coverage of weak aggregates of particles, and is distinguished from, for example, “primary particles” that form a single carbon black strong aggregate. A carbon black strong aggregate has dimensions on the scale of about 0.1 μm, which is below the resolution of optical microscopy. In relation to macro-dispersion measurements, this particle "diameter" is defined herein as the "area equivalent diameter" of the filler, and is typically in the micron range. Thus, the dispersion state can be represented by the form of the particle size distribution, whether by the area coverage of the particles or by the number of particles per unit area of ​​a certain size.

[0052] Alternatively, if the filler contains only carbon black and 10-100% by weight (based on the filler) of recycled carbon, for example 10-90% by weight, 15-80% by weight, 20-60% by weight, or 30-50% by weight of recycled carbon, preferably only wet-ground recycled carbon, it may exhibit a macrodispersion of up to 1.9ln(x)+0.2, for example 1.9ln(x)-3.2 to 1.9ln(x)+0.2.

[0053] Exemplary types of elastomers include, but are not limited to, polymers such as rubber, 1,3-butadiene, styrene, isoprene, isobutylene, 2,3-dialkyl-1,3-butadiene (where alkyl may be methyl, ethyl, propyl, etc.), acrylonitrile, ethylene, and propylene (e.g., homopolymers, copolymers, and / or terpolymers). Elastomers may have a glass transition temperature (Tg) in the range of about -120°C to about 50°C, as measured by differential scanning calorimetry (DSC). Examples include, but are not limited to, styrene-butadiene rubber (SBR), natural rubber and their functionalized derivatives, such as epoxidized and chlorinated rubber, polybutadiene rubber, polyisoprene rubber, ethylene-propylene copolymer (e.g., EPDM), isobutylene rubber (e.g., butyl rubber), polychloroprene rubber, nitrile rubber, hydrogenated nitrile rubber, polyisoprene rubber, polysulfurized rubber, polyacrylate elastomers, fluoroelastomers, perfluoroelastomers, and any of their oil-extracted derivatives. Any of the aforementioned blends and / or functionalized derivatives may also be used. Natural rubber may also be treated to chemically or enzymatically modify or reduce various non-rubber components.

[0054] Specific suitable synthetic rubbers include: copolymers of about 10 to about 70% by weight of styrene and about 90 to about 30% by weight of butadiene, for example, copolymers of 19 parts styrene and 81 parts butadiene, copolymers of 30 parts styrene and 70 parts butadiene, copolymers of 43 parts styrene and 57 parts butadiene, and copolymers of 50 parts styrene and 50 parts butadiene; polymers and copolymers of conjugated dienes, for example, polybutadiene, polyisoprene, polychloroprene, and such conjugated dienes, and Copolymers with ethylene group-containing monomers that can be copolymerized with these include, for example, styrene, methylstyrene, chlorostyrene, acrylonitrile, 2-vinylpyridine, 5-methyl-2-vinylpyridine, 5-ethyl-2-vinylpyridine, 2-methyl-5-vinylpyridine, allyl-substituted acrylates, vinyl ketones, methyl isopropenyl ketone, methyl vinyl ether, alpha-methylene carboxylic acid, and their esters and amides, for example, acrylic acid and dialkylacrylamide. Copolymers of ethylene with other higher alpha-olefins, such as propylene, 1-butene and 1-pentene, are also suitable for use herein.

[0055] The elastomer composite may further contain additives to facilitate mixing, promote vulcanization, or impart specific properties to the vulcanized product of the elastomer composite. Numerous additives are known to those skilled in the art and include, for example, adhesion promoters, antioxidants, ozone degradation inhibitors, coupling agents, curing agents, degradation inhibitors, plasticizers, processing aids (e.g., liquid polymers, oils, etc.), oil extenders, waxes, resins, flame retardants, extender oils, lubricants, tackifiers, vulcanization activators such as zinc oxide and fatty acids, vulcanization accelerators, and any mixtures thereof. Exemplary additives include, but are not limited to, zinc oxide and stearic acid. The general use and selection of such additives are known to those skilled in the art.

[0056] Dry pellets and / or spray-dried pellets may be combined with elastomers as described above using any drying and mixing method known to those skilled in the art.

[0057] Alternatively, the wet pellets may be combined with elastomers according to one or more teachings in U.S. Patent Publication No. 2022 / 0332016, International Publication No. 2021 / 247153, International Publication No. 2022 / 125679, International Publication No. 2022 / 125683, International Publication No. 2022 / 125677, and International Publication No. 2022 / 125675 (all of which are incorporated herein by reference). For example, the wet pellets and elastomers in solid form may be mixed in a mixer under conditions of controlled temperature to remove at least some of the water in the pellets by evaporation. The elastomers may optionally be premasticated before the introduction of the wet pellets. The wet filler may be added all at once or in fixed amounts.

[0058] Any suitable mixer, such as a Banbury or Brabender mixer, or other internal or enclosed mixer, or open mixer, or extruder or continuous mixer or kneading mixer, or a combination thereof, may be used to combine wet pellets with elastomer. Other mixers include kneading-type internal mixers. Commercial internal mixers from Farrel-Pomini, Harburg Freudenberger Maschinenbau GmbH (HF), Kobelco, or Pelmar Eng'r Ltd can be used. Compared to the option of using an internal circuit of steam, water, or other fluid in a rotor, or / or in addition, an internal mixer may have a cooling or heating jacket in one or more areas or parts of the mixing chamber to control the temperature of the components being mixed therein. This allows for the creation of one or more heating / cooling areas in the wall or part of the wall of the mixer. The mixer may be a single-stage mixer or a multi-stage mixer (e.g., two or more stages). Examples of mixers and designs that can be used are described in European Patent No. 2,423,253 and U.S. Patent No. 7,556,419 (these disclosures are incorporated herein by reference).

[0059] Alternatively, the mixer may be a continuous mixer. For example, solid elastomers and wetting fillers may be mechanically processed using one or more continuous internal mixers, twin-screw extruders, single-screw extruders, or roll mills, as described in U.S. Patent No. 9,855,686 (the disclosure of which is incorporated herein by reference). Suitable mixing and kneading devices are well known and commercially available, and include, for example, the Unimix Continuous Mixer and MVX (Mixing, Degassing, Extrusion) Machine from Farrel Pomini Corporation (Ansonia, Connecticut), the FCM® Farrel Continuous Mixer from Pomini, Inc., long-screw continuous mixers, Pomini continuous mixers, twin-screw co-rotating meshing extruders, twin-screw reverse-rotating non-meshing extruders, continuous mixing extruders, twin-screw kneading extruders manufactured by Kobe Steel, Ltd., and Kobe continuous mixers. Alternative kneading devices suitable for use with one or more embodiments disclosed herein are familiar to those skilled in the art.

[0060] Mixing can be carried out using a mixer having at least one rotor, and the mixer may be one or more of a kneader, roll mill, screw extruder, twin-screw extruder, multi-screw extruder, continuous mixer, and / or twin-screw extruder. Mixing can be carried out using a mixer having at least one rotor, and the mixer may have a two-blade rotor, a four-blade rotor, a six-blade rotor, an eight-blade rotor, and / or one or more screw rotors.

[0061] The mixing process for combining wet pellets with elastomers can be a single-step or multi-step process. In a multi-step process, one or more mixers or mixer types can be used. For steps in which an internal mixer is used, the packing percentage in each such step can be independently 72% or less, 70% or less, or 68% or less, or 66% or less, for example, about 30%-72%, 40%-70%, 45%-70%, 30%-60%, 50-72%, 50-70%, 50-68%, 60-72%, 60-70%, 60-68%, 65-72%, 65-70%, 65-68%, or 40-60% or 50-60%. The mixer temperature can be controlled to control the temperature of the mixture, the amount of water evaporating, or both. For example, in a multi-stage process, the amount of water evaporated from the mixture in the first mixing stage and one or more subsequent stages can be controlled by controlling the mixer temperature for each stage. For example, the liquid content of the discharged composite can be 10% to 99.9% (weight %), 10% to 95%, or 10% to 50% lower than the liquid content of the material put into the mixer. Alternatively, the rate of liquid discharge from the composite or mixture during mixing, for example by evaporation, can be measured as the time-averaged rate of liquid discharge per kg of the composite or mixture (e.g., total liquid removed / (discharge time × composite weight)), and this rate may be 0.01 to 0.14 kg / (min·kg) or 0.01 to 0.07 kg / (min·kg) or other rates below or above this range.

[0062] Alternatively, the mixing is controlled in one or more stages, with a predetermined total specific energy (based on dry weight, the energy applied to the mixing system driving one or more rotors per mass of the composite), for example, 1,000 kJ / kg composite material (or per 1 kg of mixture present in the mixer) to 10,000 kJ / kg composite material (or per 1 kg of mixture present in the mixer), for example, 2,000 kJ / kg to 5,000 kJ / kg or 1,500 kJ / kg to 8,000 kJ / kg, 1,500 kJ / kg to 7,000 kJ / kg, 1,500kJ / kg to 6,000kJ / kg, 1,500kJ / kg to 5,000kJ / kg, 1,500kJ / kg to 3,000kJ / kg, 1,600kJ / kg to 8,000kJ / kg, 1,600kJ / kg to 7,000kJ / kg, 1,600kJ / kg to 6,000kJ / kg, 1,600kJ / kg to 5,000kJ / kg, 1,600kJ / kg to 4,000kJ / kg, 1,600kJ / kg to 3,000kJ / kg, or any other value within these ranges is possible. Alternatively, the specific energy applied to the mixture may be divided to ensure that a certain amount of specific energy is applied in part, for example, before or after 75% of the filler is added to the mixer. In other words, it is not necessary to add the entire packing material at once. The mixing time at each stage may be any appropriate time, for example, 1 to 40 minutes, 1 to 20 minutes, 1 to 15 minutes, 5 to 30 minutes, 5 to 20 minutes, 5 to 15 minutes, or 1 to 12 minutes, 1 to 10 minutes, 3 to 30 minutes, or other times. Alternatively, the dump discharge temperature at each stage may be 120°C to 180°C, 120°C to 190°C, 130°C to 180°C, for example, 140°C to 180°C, 150°C to 180°C, 130°C to 170°C, 140°C to 170°C, 150°C to 170°C, or other temperatures within or outside these ranges.

[0063] Following any one or more mixing steps or stages, the resulting composite may be subjected to one or more post-processing steps, for example, to mold or form the composite and / or to enable improved handling. Post-processing may provide a composite that can be dried, homogenized, extruded, calendered, crushed, granulated, cut, packaged, or sheeted. The composite may be compounded and vulcanized immediately, or it may be held for a period of time before compounding. Suitable apparatus for various post-processing steps includes, but is not limited to, one or more internal mixers, kneaders, roll mills, open mills, screw extruders, twin-screw extruders, multi-screw extruders, continuous mixers, and / or twin-screw discharge extruders fitted with roller dies (e.g., twin-screw sheeters) or stationary knives. Depending on which device is used, it may be desirable to process the composite through the device two or more times, or through a series of similar or different devices having the same or different operating settings (e.g., speed, temperature, energy input, etc.). Alternatively, or furthermore, the elastomer composite may be combined with added fillers, added elastomers, or both, before or as part of the vulcanization process. The additional fillers may be the same as or different from the particulate fillers in the elastomer composite and may include any fillers known to those skilled in the art, in which case they include the fillers listed as additional and auxiliary fillers, and additional wet-ground recycled carbon. The added fillers and / or elastomers may increase or decrease the filler concentration in the vulcanized product relative to the elastomer composite.

[0064] To vulcanize elastomer composites, the elastomer composites are combined with a curing agent package containing a crosslinking agent, any necessary activators and accelerators, antioxidants, and any additional additives of any of those listed above. When sulfur is used as a crosslinking agent, typical activators include zinc oxide and / or stearic acid, and typical accelerators include sulfonamides such as N-tert-butyl-2-benzothiazole sulfenamide (TBBS) and N-cyclohexyl-2-benzothiazole sulfonamide (CBS). Antioxidants include N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD) and those listed in International Publication No. 2012 / 037244. Other curing agents used in rubber processing include peroxides, urethane crosslinking agents, metal oxides, and acetoxysilane mixtures. Sulfur-based and other crosslinking systems, as well as additional suitable components for methods of mixing and vulcanizing elastomer composites, are known to those skilled in the art. For example, typical methods used in rubber compounding are described in Maurice Morto, Rubber Technology, 3rd Edition, Van Norstrand Reinhold Company, New York, 1987, and 2nd Edition, Van Norstrand Reinhold Company, New York, 1973.

[0065] Various rubber articles may incorporate vulcanized materials. For example, vulcanized materials may be incorporated into tires, such as pneumatic tires, non-pneumatic tires, or solid tires. For example, vulcanized materials may be incorporated into tire treads, tire carcasses, undertreads, inner liners, sidewalls, sidewall inserts, wire skims, or cushion gum for retreaded tires. Alternatively, the vulcanized material may be incorporated into hoses, linings, liners, seals, gaskets, vibration damping articles, trucks, track pads for truck propulsion vehicle systems, engine mounts, seismic stabilization devices, screens for mining equipment, linings for mining equipment, conveyor belts, chute liners, slurry pump liners, mud pump impellers, valve seats, valve bodies, piston hubs, piston rods, plungers, slurry mixing impellers and slurry pump impellers, crusher liners, cyclones and liquid cyclones, expansion joints, linings for dredging pumps and outboard motor pumps for marine equipment, shaft seals for ships, oil, space, and other applications, propeller shafts, or linings for pipes for transporting, for example, oil sands or tar sands. Alternatively, the vulcanized material may be incorporated into engine mounts, bushings, fillers, windshield wipers, automotive parts, seals, gaskets, housings, and wheels or track elements.

[0066] The vulcanized elastomer composite can exhibit a macrodispersion of up to 0.03x + 4.4, for example, 0.03x to 0.03x + 4.4, especially when the filler contains 10 to 100% by weight, for example, 10 to 90% by weight, 15 to 80% by weight, 20 to 60% by weight, or 30 to 50% by weight of recycled carbon, preferably wet-ground recycled carbon, where x is the proportion of recycled carbon in the fine particulate filler and macrodispersion is the area percentage of undispersed filler particles larger than 5 μm, as determined by optical microscopy in reflection mode. Alternatively, or further, if the filler contains only carbon black and 10-100% by weight (based on filler) of recycled carbon, for example 10-90% by weight, 15-80% by weight, 20-60% by weight, or 30-50% by weight of recycled carbon, preferably wet-ground recycled carbon, the vulcanized elastomer composite may exhibit a macrodispersion of up to 1.9ln(x)+0.2, for example 1.9ln(x)-3.2 to 1.9ln(x)+0.2. The resulting vulcanized product may have fatigue properties equivalent to or 10% or less of a vulcanized product produced via the same process and the same composition, except that it has ASTM N550 carbon black instead of recycled carbon. Alternatively, or further, the resulting vulcanized product may have fatigue properties equivalent to or more than 90% of a vulcanized product produced via the same method and the same composition, except that it has recycled carbon replaced by the same amount of additional filler used in the vulcanized product produced according to the present invention.

[0067] The present invention is further illustrated by the following embodiments, which are intended to be illustrative only. [Examples]

[0068] Example 1 Reverse osmosis-treated water (360 g) and 36 g of carbon sample (char from either CBP Cyprus or Polimix Ambiental Ltda, or Polimix 300 processed recycled carbon from Polimix Ambiental Ltda) were fed into a half-gallon ball mill containing a mixture of half-inch (3320 g) and quarter-inch (2130 g) steel media. The mill was operated continuously at 82 rpm for 6 hours under ambient conditions. The water and carbon mixture was removed from the mill and isolated from the grinding media. The char and processed recycled carbon samples were also jet-ground using a Jet Pulverizer Company 4-inch orbital Micron-Master jet mill. Using a vibrating feeder, the solid particles were fed into an eductor filled with 100 psi of ambient air and then into a chamber maintained at 40 psi.

[0069] The particle size distribution was evaluated using a Malvern Mastersizer 3000 instrument equipped with a HydroMV recirculation accessory. The HydroMV unit was filled with approximately 100 ml of deionized water. The water was recirculated through the detector window, and background measurements were performed to establish a baseline. A 0.02 g sample of dry powder (e.g., char or processed recycled carbon) was combined with 50 ml of 1:3 (v:v) ethanol / water and 0.05% Triton® X100 dispersant. For wet samples and dispersions (e.g., wet pulverized recycled carbon), the solid content of the dispersion was determined, and sufficient material was added to the 1:3 ethanol / water mixture to prepare a dispersion with 0.02 g of solids in 50 ml of liquid containing 0.05% Triton® X100 dispersant. For both wet and dry samples, the final mixture was probe-sonicated for 10 minutes at 50% amplitude using a Branson 450D sonicator equipped with a 0.5-inch replaceable titanium tip probe. The newly dispersed sample was added dropwise to the HydroMV unit until the obscuration level reached approximately 30%. Recirculation was performed for an additional 10 seconds before starting the measurement. The instrument settings were as described in Table 1 below.

[0070] [Table 1]

[0071] The results are shown in Figures 1-3. Figure 1 shows the particle size distribution of raw char (CBP Cyprus), where the graph represents raw char (dotted line), jet mill (dashed line), or ball mill (solid line). Figure 2 shows the particle size distribution of ball-ground samples of char (CBP Cyprus - dashed line - and Polimix Ambiental - dashed line) and processed recycled carbon (Polymix 300 - solid line). Figure 3 shows the particle size distribution of jet-ground samples of char (CBP Cyprus - dashed line - and Polimix Ambiental - dashed line) and Polymix 300 processed recycled carbon (solid line). The results indicate that grinding in the presence of water provides more effective grinding, with the distribution curve having maximum intensity at particle sizes of 0.1-2 microns.

[0072] Example 2 1.1 kg of wet-ground recycled carbon slurry with a liquid / solids ratio of 10:1 (w / w) is poured into a 20 HP Feeco pin mixer containing 1 kg of cottony (unpelletized) N550 carbon black at ambient temperature. Mixing is continued at 1000 rpm for 90 seconds, after which the pellets are discharged from the mixer. The resulting blended carbon pellets are then dried at 110°C for 24 hours to achieve a moisture content of less than 1%. The dried pellets are then incorporated into a rubber compound and compared to reference N550 carbon black.

[0073] Example 3 Ball grinding: Water treated by reverse osmosis and 36 g of commercially available pyrolysis carbon (technical carbon black, Reoil Sp.z oo, Myslenice, Poland) were placed in a half-gallon ball mill containing a mixture of half-inch (3320 g) and quarter-inch (2130 g) steel media. Using sufficient water, either an 8.5 wt% (sample 1) or 20 wt% (samples 2, 3, 4, 5, and 6) mixture was produced, as shown in Table 2. The mill was operated continuously at 82 rpm for 24 hours under ambient conditions. The resulting mixture was removed from the mill and isolated from the grinding media to obtain a slurry of wet-ground regenerated carbon. This process was repeated as needed to obtain sufficient wet-ground regenerated carbon and produce rubber as described below. A 25 wt% slurry was prepared in the same manner and had sufficient fluidity for good grinding.

[0074] Jet pulverization: Materials for comparisons 1, 2, 3, 4, and 5 were prepared by jet pulverizing commercially available pyrolysis carbon (technical carbon black, Reoil Sp.z oo, Myslenice, Poland) using a 4-inch orbital Micron-Master jet mill (Jet Pulverizer Company). Using a vibrating feeder, the solid particles were fed into an eductor filled with ambient air at 80 psi and then into a chamber maintained at 40 psi at approximately 60 g / min. ASTM N550 carbon black (Sterling SO carbon black, Cabot Corporation) was jet pulverized in the same manner.

[0075] Pelleting: A 10-hp pin pellet mill was used at approximately 80% filling density. For comparative samples 1, 2, 3, 4, and 5, commercially available pyrolysis carbon (technical carbon black, Reoil Sp.z oo, Myslenice, Poland) and jet-milled ASTM N550 carbon black were added to the pellet mill in the proportions shown in Table 2 and mixed at 1000 rpm for 15 seconds to obtain a homogeneous blend of cottony carbon. For comparative samples 2a and 5a, jet-milled ASTM N550 carbon black was added to the pellet mill without blending. Next, water was added to the pellet mill at a ratio of approximately 43% by weight. For all comparative samples, the pellet mill was operated at 1000 rpm for 1 minute at ambient temperature. The resulting pellets were either used as is or dried to a moisture level of less than 1% by weight as shown in Table 2 below. The relative amounts of recycled carbon in the resulting pellets are shown in Table 2.

[0076] For samples 1-5, an appropriate amount of jet-ground carbon black (to give the proportion of wet-ground recycled carbon shown in Table 2) was added to the pellet maker. Next, the slurry obtained from ball grinding (samples 1, 2, 3, 4, and 5) was added to the pin pellet maker to produce wet pellets with 52-62% by weight of water. The relative amount of wet-ground recycled carbon and slurry concentration in the resulting pellets are shown in Table 2. For all samples, the pellet maker was operated at 1000 rpm for 1 minute at ambient temperature. As shown in Table 2 below, the samples were partially dried (to 43% moisture) or dried to a moisture level of less than 1% by weight. The partially dried samples were placed in a 125°C oven with a sample depth of approximately 10 mm and checked periodically until the desired moisture level (43% by weight as a percentage of the total weight of the wet filler) was reached. Pellet moisture was measured using a Mettler HE53 moisture analyzer (Mettler Toledo). The samples, dried to a moisture level of less than 1% by weight, were placed in a 125°C oven with a sample depth of approximately 10 mm and left overnight.

[0077] Comparative sample 6: Precipitated silica (348g of Zeosil 1165MP silica from Solvay USA, Inc.) and commercially available pyrolysis carbon (technical carbon black, Reoil Sp.zoo, Myslenice, Poland, used as is) were added to a 5-gallon poly bucket to obtain a mixture containing 26.9% by weight of pyrolysis carbon. Water was added to the particulate mixture to achieve a moisture level of 52.1% by weight, and the bucket was mixed on a roll mill for 30 minutes at 82 rpm to form pellets that were not further dried.

[0078] Sample 6: A 20 wt% slurry of precipitated silica (348 g of Zeosil 1165MP silica from Solvay USA, Inc.) and wet-ground recycled carbon was combined in a 5-gallon poly bucket to prepare a mixture with 26.9 wt% (dry basis) of wet-ground recycled carbon and a moisture level of 52.1%. The bucket was stirred on a roll mill at 82 rpm for 30 minutes to form pellets.

[0079] [Table 2]

[0080] Particle Size Distribution: The particle size distribution (PSD) of pulverized recycled carbon was measured using a scanning electron microscope. PSD was measured for two separate aqueous slurries (listed as separate samples in Table 3 below) at different concentrations of wet pulverized recycled carbon (8.5% and 20%), an aqueous slurry of wet pulverized recycled carbon and precipitated silica (sample 6), and jet-pulverized recycled carbon. The relevant recycled carbon samples were gently dispersed at a concentration of 0.2 wt% in water containing 600 ppm Triton® X 100 surfactant using a DISPERMAT disperser at 800 RPM for 5 minutes. Next, the 0.2 wt% dispersion was placed on a magnetic stirring plate and mixed with a magnetic stirring bar for 24 hours. The stirred dispersion was diluted to an appropriate concentration (0.4–4 ppm) using water containing 600 ppm Triton® X 100 for imaging by scanning electron microscopy (SEM). The diluted dispersion was vortex-mixed at 3000 RPM for 30 seconds; then, 0.8 mL of the vortex-mixed dispersion was placed on a 25 mm diameter polycarbonate membrane filter with a 100 nm aperture for filtration. The particles on the membrane filter were air-dried before SEM imaging.

[0081] The film filter was sputter-coated with platinum to reduce charging during imaging. Two sets of SEM images were acquired using a Zeiss Ultra-plus field emission SEM with an SE2 detector at an electron acceleration voltage of 3 kV. Images 15 to 40 of the first setting were acquired with a 3072 × 2304 pixel field of view and an image pixel size of 60 nm / pixel (×1500 magnification), while images 15 to 40 of the second setting were acquired with a 3072 × 2304 pixel field of view and an image pixel size of 300 nm / pixel (×300 magnification). The image positions on the film filter were randomly selected to encompass the entire filter surface area for representative sampling of particles on the filter surface. Image analysis was performed using macros in NIH ImageJ software. SEM images were processed by 1) minimizing the non-uniform image background using a pseudo-flat-field correction method; 2) increasing particle contrast using a local contrast enhancement method with local adaptive histogram equalization in ImageJ; and 3) reducing image noise while preserving particle edges using a bi-exponential edge-preserving smoother in ImageJ. Particles were separated from the processed SEM images using local contrast differences in three different local area sizes. Size and shape parameters for all particles in the separated binary images were obtained from standard particle analysis methods in ImageJ. Depending on the width of the PSD, the total number of particles from 50,000 to 200,000 was imaged to achieve adequate accuracy. PSDs were generated by combining PSDs of submicron particles from a set of SEM images at 60 nm / pixel resolution with PSDs of particles larger than 1 micron from a set of SEM images at 300 nm / pixel resolution. To compensate for the difference in total area between low-resolution and high-resolution images, each particle collected from SEM images with a pixel size of 60 nm was counted using a number weighting coefficient equal to the ratio of the total number of particles larger than 1 micron in both the image settings with a pixel size of 300 nm and the image settings with a pixel size of 60 nm. To generate continuous PSDs from separate particle size lists, a smooth continuous cumulative particle size distribution was generated using a B-spline interpolation algorithm, and then the probability density distribution was calculated based on the first derivative of the cumulative distribution using a noise-resistant, smooth differentiator.The area-equivalent circle diameter Dcirc (equivalent to twice the value obtained by dividing the square root of the projected area in the image by π) was used as the criterion for measuring particle size. The volume weighting of the particles is based on the area of ​​the particles in the SEM image and the volume of the particles estimated from the surroundings, using the ASTM D3849 formula. The volume-weighted particle size distribution is shown in Table 3. Wet-ground recycled carbon shows a smaller particle size distribution and fewer particles larger than 2 microns and 5 microns compared to jet-ground recycled carbon.

[0082] [Table 3]

[0083] Rubber mixtures: Rubber with a particulate concentration of 50 phr was prepared using the amounts of small and curing agents shown in Table 4, as well as the amounts of SMR20 natural rubber, Buna CB24 butadiene rubber (Lanxess), or Kralex SBR 1502 styrene-butadiene rubber (Synthos) listed in Table 5 below. Furthermore, two samples were prepared by dry mixing using 100 phr of natural rubber (SMR20 grade) with 50 phr of Sterling SO3 carbon black (Comparative 7) or commercially available pyrolysis carbon (Comparative 8, Technical Carbon Black, Reoil Sp.z oo, Myslenice, Poland). All compositions were mixed in a 439 mL Brabender Prep-mixer with two cam rotors. Dry mixed samples (pellet moisture < 1 wt%) were prepared in two steps as described in Table 6, and wet mixed samples (pellet moisture > 1 wt%) were prepared in three steps as described in Table 7. Regardless of the method used, after each mixing stage, the mixture was sheeted on a two-roll mill operated at 50°C and approximately 22 rpm, followed by banding for 60 seconds, passing through a nip gap of approximately 5 mm six times, with a resting time of at least 3 hours before the next stage of mixing (or curing, after the last stage). Curing was carried out in a heated press (150°C, 2500 lbs) for a time of T90 + 10% of T90 as determined by a conventional rubber rheometer (where T90 is the time to achieve 90% vulcanization).

[0084] [Table 4] a) For use only in silica-containing formulations; HB Chemical's bis[3-(triethoxysilyl)propyl]polysulfide b) 2 phr for pellets with less than 1% by weight moisture content, otherwise 2.5 phr; N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, standard 6 PPD (Harwick Standard) c) Poly(1,2-dihydro-2,2,4-trimethylquinoline), antioxidant DQ pellets (Akrochem Corporation) d) From Akrochem Corporation e)AKROWAXTM 5031(Akrochem Corporation) f) N-tert-butyl-2-benzothiazole sulfenamide (Akrochem Corporation)

[0085] [Table 5]

[0086] [Table 6]

[0087] [Table 7]

[0088] The following tests were used to obtain performance data for each vulcanized material. Tensile stress at 100% elongation (M100) and 300% elongation (M300) was evaluated according to ASTM D412 (Test Method A, Type C) at 23°C, 50% relative humidity, and a crosshead speed of 500 mm / min. Tensile strain was measured using an extensometer. The M300 / M100 ratio is called the tensile stress ratio (or modulus ratio). The Type B tear strength of the cured rubber samples was measured at 23°C according to ASTM D624. The cured samples were cut with a guillotine and prepared for macroscopic analysis of variance. Images were digitally captured using an Idea 5Mp color mosaic camera and Spot imaging software, version 5.6.11 (Spot Imaging, Sterling Heights, MI) in conjunction with an Olympus BH-2 microscope (using a ring light as the illumination source in reflection mode). The overall magnification of the captured images was 100x. Using Picassa (Google), the contrast of particles against the background was enhanced. Using NIH ImageJ software, weak aggregates were identified and quantified using the default automatic thresholding method, appropriate background leveling (set via background subtraction ball radius), and erosion loops. Knife marks, which tend to have a circularity of less than 0.3, were distinguished from weak aggregates (circularity of 0.3 or greater). Using ImageJ software, a binary image (area equivalent diameter = (4 * area of ​​dark object / π)) was created. 1 / 2 The area-equivalent diameter of the corresponding object was defined in ). Three images of randomly selected regions of the sample were measured for each sample, and weak aggregates with a diameter of at least 5 microns were considered "undispersed".

[0089] The properties of the vulcanized products are listed in Table 8 below. The results show that the reduced proportion of large weak aggregates in the wet-ground recycled carbon of the examples correlates with a reduced undispersed area, an improved modulus ratio, and tear strength in elastomer composite vulcanized products with a larger proportion of such weak aggregates. The results are shown in Figure 4. Triangles indicate comparative samples, and circles indicate samples prepared according to embodiments of the present invention.

[0090] [Table 8]

[0091] Example 4 Water treated by reverse osmosis and 36 g of commercially available pyrolysis carbon (technical carbon black, Reoil Sp.z oo, Myslenice, Poland) are placed in a half-gallon ball mill containing a mixture of half-inch (3320 g) and quarter-inch (2130 g) steel media. Sufficient water is added to produce a 25 wt% mixture. The mill is operated continuously at 82 rpm for 24 hours under ambient conditions. The resulting mixture is removed from the mill and isolated from the grinding media to obtain a slurry of wet-ground recycled carbon, measured using the SEM method outlined above, with a d50 of less than 2700 nm and less than 15% of particles having a diameter greater than 5 microns. The slurry is distilled to remove water until the solids content is about 65-70%, and the partially dried slurry is then dried in an oven at 125°C until the moisture content is about 40-50%. The resulting wet-filler is pelletized as described above. The resulting pellets can be used as is without drying, or they can be dried to a moisture content of less than 1% and combined with an elastomer to form an elastomer composite.

[0092] The above description of preferred embodiments of the present invention is presented for illustrative and explanatory purposes only. It is not intended to limit the invention to the comprehensive or exact forms disclosed. Modifications and variations are possible in light of the above teachings or can be obtained from the practice of the invention. The embodiments have been selected and described to illustrate the principles of the invention and its practical applications, enabling those skilled in the art to utilize the invention in various embodiments, with various modifications, in various ways, to suit specific uses intended. The scope of the invention is intended to be defined by the claims and their equivalents attached to this specification.

Claims

1. A method for processing particulate carbon: Combining pyrolysis carbon with water to form a mixture, and forming an initial slurry having a solid content of 1 to 35% by weight; and A method comprising grinding the pyrolysis carbon to form a grinding slurry containing wet-ground regenerated carbon and water; wherein the volume-weighted particle size distribution of the wet-ground regenerated carbon, as measured by scanning electron microscopy, satisfies at least one of the following conditions: D50 is 2700 nm or less and particles having a particle size greater than 5 microns constitute 15% or less.

2. The method according to claim 1, wherein D50 is 1000 nm to 2700 nm, for example, 1200 nm to 2500 nm.

3. The method according to claim 1 or 2, wherein D75 is 2500 nm to 3300 nm, for example, 1700 nm to 3000 nm.

4. The method according to any one of claims 1 to 3, wherein 3% to 10% of the wet-ground recycled carbon particles have a particle size of more than 5 microns.

5. The method according to any one of claims 1 to 4, wherein 65% or less of the wet-ground recycled carbon particles, for example, 25 to 60%, have a particle size greater than 2 microns.

6. The method according to any one of claims 1 to 5, further comprising removing visible contaminants from the initial slurry.

7. The method according to any one of claims 1 to 6, wherein the initial slurry has a maximum solid content of 25% by weight.

8. The method according to any one of claims 1 to 7, wherein the combination further comprises combining at least one auxiliary filler with water to form the initial slurry.

9. The method according to claim 8, wherein the auxiliary filler is selected from the group consisting of carbon black, silicon-treated carbon black, silica-coated carbon black, precipitated silica, hydrothermal carbon, artificial polysaccharides, graphene, graphene oxide, reduced graphene oxide, nanocellulose, lignin, clay, nanoclay, metal oxides, metal carbonates, single-walled carbon nanotubes, multi-walled carbon nanotubes, carbon nanostructures, carbon black-coated particles, and mixtures of two or more of these.

10. The method according to any one of claims 1 to 9, wherein the grinding is carried out using at least one apparatus selected from a cutter mixer, ball mill, media mill, homogenizer, attritor, horizontal bead mill, rotor stator mill, and colloid mill.

11. The method according to any one of claims 1 to 10, further comprising adding at least one additional filler selected from carbon black, silicon-treated carbon black, silica-coated carbon black, carbon black-coated particles, and precipitated silica to the pulverized slurry to give the solid content of the resulting wet blended carbon mixture 25 to 70% by weight.

12. The method according to claim 11, wherein the addition includes adding an aqueous slurry containing the at least one additional filler.

13. The method according to claim 11 or 12, further comprising densifying the wet blended carbon mixture.

14. The method according to claim 13, wherein the densification includes pelletizing the wet blend carbon mixture to form pellets, or spray-drying the wet blend carbon mixture.

15. The method according to claim 14, further comprising drying the pellets.

16. The water is a continuous flow of water; The grinding slurry is a continuous flow of the grinding slurry; The aforementioned combination includes metering the pyrolysis carbon into the continuous flow of water; The method according to any one of claims 1 to 15.

17. The method according to claim 16, wherein the combination further comprises measuring at least one auxiliary filler into the continuous flow of water.

18. The method according to claim 17, wherein the auxiliary filler is selected from the group consisting of carbon black, silicon-treated carbon black, silica-coated carbon black, precipitated silica, hydrothermal carbon, artificial polysaccharides, graphene, graphene oxide, reduced graphene oxide, nanocellulose, lignin, clay, nanoclay, metal oxides, metal carbonates, single-walled carbon nanotubes, multi-walled carbon nanotubes, carbon nanostructures, carbon black-coated particles, and mixtures of two or more of these.

19. The method according to any one of claims 16 to 18, further comprising weighing at least one additional filler selected from carbon black, silicon-treated carbon black, silica-coated carbon black, carbon black-coated particles, and precipitated silica into the continuous flow of the pulverized slurry to make the solid content of the resulting continuous flow of the wet blended carbon mixture 25 to 70% by weight.

20. The method according to claim 19, wherein the weighing includes weighing the aqueous slurry of the additional filler into the continuous flow of the pulverized slurry.

21. The method according to any one of claims 16 to 20, further comprising granulating the wet blended carbon mixture.

22. The method according to claim 21, wherein the granulation includes pelletizing the wet blended carbon mixture to form pellets, or spray-drying the wet blended carbon mixture.

23. The method according to claim 22, further comprising drying the pellets.

24. The method according to any one of claims 1 to 23, further comprising granulating the solid content in the pulverized slurry.

25. The method according to claim 24, wherein the granulation includes spray-drying the pulverized slurry or pelletizing the solid components in the pulverized slurry.

26. Pellets manufactured by the method described in any one of claims 1 to 25.

27. A particulate filler containing at least 10% by weight (on a dry basis) of recycled carbon, wherein the volume-weighted particle size distribution of the recycled carbon, as measured by scanning electron microscopy, satisfies at least one of the following conditions: D50 is 2700 nm or less and particles having a particle size greater than 5 microns constitute 15% or less.

28. The particulate filler according to claim 27, wherein D50 is 1000 nm to 2700 nm, for example, 1200 nm to 2500 nm.

29. The particulate filler according to claim 27 or 28, wherein D75 is 2500 nm to 3300 nm, for example, 1700 nm to 3000 nm.

30. The fine particle filler according to any one of claims 27 to 29, wherein 3% to 10% of the recycled carbon particles have a particle size greater than 5 microns.

31. The fine particle filler according to any one of claims 27 to 30, wherein 65% or less of the recycled carbon particles, for example, 25 to 60%, have a particle size greater than 2 microns.

32. The particulate filler according to any one of claims 27 to 31, wherein the particulate filler contains 10 to 100% by weight, 10 to 90% by weight, 15 to 80% by weight, 20 to 60% by weight, or 30 to 50% by weight of recycled carbon.

33. A particulate filler according to any one of claims 27 to 32, further comprising one or more auxiliary fillers selected from carbon black, silicon-treated carbon black, silica-coated carbon black, precipitated silica, hydrothermal carbon, artificial polysaccharides, graphene, graphene oxide, reduced graphene oxide, nanocellulose, lignin, clay, nanoclay, metal oxides, metal carbonates, single-walled carbon nanotubes, multi-walled carbon nanotubes, carbon nanostructures, and carbon black-coated particles.

34. The particulate filler according to any one of claims 27 to 33, wherein the particulate filler has a water content of 15 to 80% by weight, for example, 40 to 60% by weight.

35. The particulate filler according to any one of claims 27 to 34, wherein the particulate filler is in the form of pellets.

36. The fine particle filler according to claim 33, wherein the pellet has a moisture content of 15 to 80% by weight, for example, 40 to 60% by weight.

37. The pellets contain 3% or less of water, as described in claim 34.

38. The particulate filler according to any one of claims 35 to 37, wherein the pellet substantially consists of the particulate filler, any water, and any binder.

39. A pellet comprising a particulate filler according to any one of claims 27 to 38, and further comprising at least one additional filler selected from carbon black, silicon-treated carbon black, silica-coated carbon black, carbon black-coated particles, and precipitated silica.

40. The fine particle filler according to any one of claims 27 to 39, wherein the recycled carbon is wet-ground recycled carbon.

41. An elastomer composite comprising an elastomer and a mixture of 30 to 90 phr of fine particle filler, wherein the fine particle filler contains at least 10% by weight of recycled carbon, satisfying at least one of the following conditions: a D50 (volume weight) of 2700 nm or less, as measured by scanning electron microscopy, and 15% (volume weight) or less of particles having a particle size greater than 5 microns.

42. The elastomer composite according to claim 41, wherein the fine particle filler contains 10 to 100% by weight, 10 to 90% by weight, 15 to 80% by weight, 20 to 60% by weight, or 30 to 50% by weight of recycled carbon.

43. The elastomer composite according to claim 41 or 42, wherein D50 is 1000 nm to 2700 nm, for example, 1200 nm to 2500 nm.

44. The elastomer composite according to any one of claims 41 to 43, wherein D75 is 2500 nm to 3300 nm, for example, 1700 nm to 3000 nm.

45. The elastomer composite according to any one of claims 41 to 44, wherein 3% to 10% of the recycled carbon particles have a particle size greater than 5 microns.

46. The fine particle filler according to any one of claims 41 to 45, wherein 65% or less of the regenerated particles, for example, 25 to 60%, have a particle size greater than 2 microns.

47. The elastomer composite according to any one of claims 41 to 46, wherein the fine particle filler is present in an amount of 30 to 70 phr, for example, 35 to 60 phr or 40 to 55 phr.

48. The elastomer composite according to any one of claims 41 to 47, wherein the elastomer composite exhibits a macrodispersion of up to 0.03x + 4.4, where x is the proportion of recycled carbon in the fine particle filler, and the macrodispersion is the area ratio of undispersed filler particles larger than 5 μm, as determined by optical microscopy in reflection mode.

49. The elastomer composite according to any one of claims 41 to 48, wherein the elastomer composite exhibits a macrodispersion of 0.03x to 0.03x + 4.4, where x is the proportion of recycled carbon in the fine particle filler, and the macrodispersion is the area ratio of undispersed filler particles larger than 5 μm, determined by optical microscopy in the reflection mode.

50. The elastomer composite according to any one of claims 41 to 49, wherein the fine particle filler further comprises one or more of the following: carbon black, silicon-treated carbon black, silica-coated carbon black, precipitated silica, hydrothermal carbon, artificial polysaccharides, graphene, graphene oxide, reduced graphene oxide, nanocellulose, lignin, clay, nanoclay, metal oxides, metal carbonates, single-walled carbon nanotubes, multi-walled carbon nanotubes, carbon nanostructures, and carbon black-coated particles.

51. The elastomer composite according to any one of claims 41 to 50, wherein the particulate filler is recycled carbon and carbon black, the elastomer composite exhibits a macrodispersion of up to 1.9 ln(x) + 1.2, where x is the proportion of recycled carbon in the particulate filler, and the macrodispersion is the area ratio of undispersed filler particles larger than 5 μm, determined by optical microscopy in reflection mode.

52. The elastomer composite according to claims 41 to 51, wherein the particulate filler is recycled carbon and carbon black, the elastomer composite exhibits a macrodispersion of 1.9 ln(x) - 3.2 to 1.9 ln(x) + 0.2, where x is the proportion of recycled carbon in the particulate filler, and the macrodispersion is the area ratio of undispersed filler particles larger than 5 μm, determined by optical microscopy in the reflection mode.

53. The elastomer composite according to any one of claims 41 to 52, wherein the elastomer is selected from natural rubber, functionalized natural rubber, styrene-butadiene rubber, functionalized styrene-butadiene rubber, polybutadiene rubber, functionalized polybutadiene rubber, polyisoprene rubber, ethylene-propylene copolymer, isobutylene rubber, polychloroprene rubber, nitrile rubber, hydrogenated nitrile rubber, polysulfide rubber, polyacrylate elastomer, fluoroelastomer, perfluoroelastomer, and blends thereof.

54. The elastomer composite according to any one of claims 41 to 53, wherein the recycled carbon is wet-ground recycled carbon.

55. The elastomer composite according to any one of claims 41 to 54, wherein the elastomer composite is a vulcanized elastomer composite.

56. A tire tread comprising a vulcanized product of a mixture comprising an elastomer composite and a curing agent package as described in any one of claims 41 to 54.

57. An article comprising a vulcanized product of a mixture comprising an elastomer composite and a curing agent package as described in any one of claims 41 to 54.

58. The article according to claim 57, wherein the article is incorporated into a pneumatic tire, a non-pneumatic tire, or a solid tire.

59. The article according to claim 57 or 58, wherein the article is selected from tire treads, undertreads, inner liners, sidewalls, sidewall inserts, wire skims, and cushion gum for retreaded tires.

60. The article according to claim 57, wherein the article is selected from hoses, linings, liners, seals, gaskets, vibration-damping articles, trucks, track pads for truck propulsion vehicle systems, engine mounts, seismic stabilization devices, screens for mining equipment, linings for mining equipment, conveyor belts, chute liners, slurry pump liners, mud pump impellers, valve seats, valve bodies, piston hubs, piston rods, plungers, slurry mixing impellers and slurry pump impellers, crusher liners, cyclones and liquid cyclones, expansion joints, linings for dredging pumps and outboard motor pumps for marine equipment, shaft seals for ships, oil, space and other applications, propeller shafts, pipe linings, engine mounts, bushings, fillers, windshield wipers, automotive parts, seals, gaskets, housings, wheel elements and track elements.

61. A vulcanized product of a mixture comprising an elastomer composite and a curing agent package according to any one of claims 41 to 54, wherein the vulcanized product has fatigue properties equivalent to or at least 90% of a vulcanized product produced by the same process and the same composition, except that the vulcanized product has ASTM N550 carbon black instead of recycled carbon.

62. A vulcanized product of a mixture comprising an elastomer composite and a curing agent package according to any one of claims 41 to 54, wherein the vulcanized product exhibits a macrodispersion of up to 0.03x + 4.4, where x is the proportion of recycled carbon in the fine particle filler, and the macrodispersion is the area proportion of undispersed filler particles larger than 5 μm, as determined by optical microscopy in the reflection mode.

63. A vulcanized product of a mixture comprising an elastomer composite and a curing agent package according to any one of claims 41 to 54, wherein the vulcanized product exhibits a macrodispersion of 0.03x to 0.03x + 4.4, where x is the proportion of recycled carbon in the fine particle filler, and the macrodispersion is the area ratio of undispersed filler particles larger than 5 μm, as determined by optical microscopy in the reflection mode.

64. A vulcanized product of a mixture comprising an elastomer composite and a curing agent package according to any one of claims 41 to 54, wherein the particulate filler is recycled carbon and carbon black, the vulcanized product exhibits a macrodispersion of up to 1.9 ln(x) + 0.2, where x is the proportion of recycled carbon in the particulate filler, and the macrodispersion is the area ratio of undispersed filler particles larger than 5 μm, as determined by optical microscopy in reflection mode.

65. A vulcanized product of a mixture comprising an elastomer composite and a curing agent package according to any one of claims 41 to 54, wherein the particulate filler is recycled carbon and carbon black, the elastomer composite exhibits a macrodispersion of 1.9 ln(x) - 3.2 to 1.9 ln(x) + 0.2, where x is the proportion of recycled carbon in the particulate filler, and the macrodispersion is the area ratio of undispersed filler particles larger than 5 μm, as determined by optical microscopy in the reflection mode.

66. An elastomer composite comprising a mixture of an elastomer and a particulate filler of 30 to 90 phr, wherein the particulate filler contains at least 10% by weight of recycled carbon, and the elastomer composite exhibits a macrodispersion of up to 0.03x + 4.4, where x is the proportion of recycled carbon in the particulate filler, and the macrodispersion is the area ratio of undispersed filler particles larger than 5 μm, as determined by optical microscopy in the reflection mode.

67. The elastomer composite according to claim 66, wherein the elastomer composite exhibits a macrodispersion of 0.03x to 0.03x + 4.4, where x is the proportion of recycled carbon in the fine particle filler, and the macrodispersion is the area ratio of undispersed filler particles larger than 5 μm, determined by optical microscopy in the reflection mode.

68. An elastomer composite comprising a mixture of an elastomer and a particulate filler of 30 to 90 phr, wherein the particulate filler contains at least 10 wt% recycled carbon together with the remainder carbon black, and the elastomer composite exhibits a macrodispersion of up to 1.9 ln(x) + 1.2, where x is the proportion of recycled carbon in the particulate filler, and the macrodispersion is the area ratio of undispersed filler particles larger than 5 μm, as determined by optical microscopy in reflection mode.

69. The elastomer composite according to claim 68, wherein the elastomer composite exhibits a macrodispersion of 1.9ln(x)-3.2 to 1.9ln(x)+0.2, where x is the proportion of recycled carbon in the fine particle filler, and the macrodispersion is the area ratio of undispersed filler particles larger than 5 μm, determined by optical microscopy in the reflection mode.

70. The elastomer composite according to any one of claims 66 to 69, wherein the elastomer composite is vulcanized.

71. The elastomer composite according to any one of claims 66 to 70, wherein the recycled carbon is wet-ground recycled carbon.

72. The elastomer composite according to any one of claims 66 to 71, wherein the recycled carbon satisfies at least one of the following conditions: the D50 (volume weight) measured by scanning electron microscopy is 2700 nm or less, and particles having a particle size greater than 5 microns constitute 15% (volume weight) or less.

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