Rubber compound for producing tires, comprising recovered carbon black

Abstract

The invention relates to a rubber compound for vehicle tires, wherein the rubber compound contains the following components: • at least one diene rubber, • recovered carbon black having an organic residue content of 0–5%, a carbon content of 70–85% and an inorganic ash content of 15–30%, wherein the process for producing the recovered carbon black comprises the following steps: • selecting used tires, • comminuting the used tires to form a used tire granulate • pyrolyzing the used tire granulate with a residence time between 2 and 4 hours at a material temperature between 550°C and 750°C • grinding the recovered carbon black • wet-pelletizing the ground recovered carbon black.

Description

[0001] Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0002] 1

[0003] DESCRIPTION

[0004] Rubber compound for tire manufacturing with recovered industrial carbon black

[0005] The present invention relates to a rubber compound for tire production using recovered industrial carbon black.

[0006] The recycling of waste and residual materials is gaining increasing importance due to the growing scarcity and associated price increases of raw materials, especially fossil fuels. The development of new energy sources and processes, particularly renewable energies, is receiving increasing attention and support. Pyrolysis technology, specifically the pyrolytic recycling of petroleum products such as tires, is attracting growing interest.

[0007] The production of tires, pigments, and paints requires modified carbon with a high surface-to-volume ratio. This industrial carbon black is an organic raw material produced by the controlled combustion of gaseous or liquid raw materials from the petroleum, natural gas, or coal industries. Aromatic compounds with a high carbon-to-hydrogen ratio are used in this process.

[0008] There are two main methods for producing conventional industrial carbon black (virgin carbon black (vCB)), which differ in the type of heat input: partial oxidation and external heat input. In partial oxidation, a portion of the raw material is burned with controlled airflow to generate the heat required for temperatures between 1,200 °C and 1,900 °C. The resulting product is then cooled and dried. In external heat input, the necessary heat is supplied from an external source.

[0009] The most frequently used process is the furnace carbon black process. This process involves the removal of highly aromatic, viscous residues from oil refineries, coking plants, or Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0010] Two catalytic cracking plants are used as feedstock. This process follows the principles of partial oxidation. The required high temperatures are generated in the combustion chamber by burning natural gas or oil. The highly aromatic carbon black oils are then injected into the hot gas. Due to the incomplete combustion and the parallel pyrolysis process, industrial carbon black is produced along with hydrogen and other gases. After a defined reaction time in the combustion chamber, the gas mixture is cooled and separated from the remaining process gas by a filter system.

[0011] A disadvantage of these manufacturing methods is that they are very energy-intensive and produce high CO2 emissions. Therefore, there is great interest in the reuse of industrial carbon black.

[0012] In particular, recovered carbon black (rCB) (ASTM D8178) from end-of-life tires is a promising technology for returning tire components to the material cycle and thus increasing tire circularity. Current recycling methods are mostly limited to energy recovery, releasing significant amounts of CO2 through the complete combustion of carbon-containing tire components. End-of-life tire pyrolysis enables the reuse of individual components, including in new tires, and emits significantly less CO2 due to its low-oxygen combustion. Specifically, the pyrolysis gases and oils produced during pyrolysis can be used for energy generation or as feedstock in the chemical industry. This offers significant advantages in terms of overall sustainability compared to previously used technologies such as carbon black from energy-intensive furnace processes.

[0013] The use of rCB depends on selected raw materials and specific pyrolysis conditions. Carbon black is a widely used filler in rubber compounds because it significantly improves the strength of vulcanized rubber compared to rubber without filler. Various types of carbon black are used in the rubber industry, including N-220, N-330, N-550, and N-660 according to the ASTM D1765-14 standard. Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0014] 3

[0015] Pyrolysis processes and pyrolysis devices for the production of recovered industrial carbon black are known from the prior art.

[0016] WO 2010 / 127664 A1 discloses a multi-stage, energy-autonomous, and continuously operating pyrolysis process for the fractional recovery of valuable materials and energy from free-flowing, highly cross-linked organic compounds, in particular from waste tire, sealing profile, and other plastic granules, as well as an apparatus for carrying out the process. To develop an energy-autonomous, continuously operating pyrolysis process for free-flowing organic granules, it is proposed therein that the granules pass gravimetrically from top to bottom through a vertical, multi-stage pyrolysis reactor, being heated and pyrolyzed at process temperatures that can be adjusted in stages, ranging from 300 to 1,200 °C.Subsequent fractional condensation of the pyrolysis vapors results in the recovery of oil and gas compounds, and downstream engine use of the pyrolysis gas generates the energy required for the pyrolysis process.

[0017] WO 2012 / 092924 A1 describes a thermal reactor for the continuous thermolytic recycling of waste tires, vulcanization residues, and waste plastic granules, and similar products. The thermal reactor has an inlet section, a heating zone middle section, and an outlet section, arranged vertically one above the other. A suction pipe is centrally located in the heating zone middle section of the thermal reactor. The surface of this pipe has numerous bores and / or slots for venting the resulting short-chain hydrocarbon vapors. Conical bells are mounted one above the other on the suction pipe. The outer shell of the heating zone middle section has a multitude of radially arranged heating plates, offset from each other in the stacked heating levels.

[0018] WO 2011 / 035812 A1 concerns a multi-stage thermal treatment by Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0019] 4

[0020] Rubber waste, in particular used tires. The process comprises several steps in which a product granulate made from rubber waste is transferred to three different, successive heating zones of a reactor. In the heating zones, the product granulate is first heated to a temperature between 100° and 200°C, preferably 150° to 180°C, then to a second temperature between 200° and 350°C, and finally to a third temperature between 300° and 600°C. The temperature is maintained until no further oil is released in the respective heating zone. As a final step, the product granulate is removed from the reactor and the desired solid materials are separated.

[0021] EP 3 627 050 B1 describes a pyrolysis plant with a pyrolysis reactor having an upper reactor screw and a lower reactor screw.

[0022] A pyrolysis process for recycling used tires is known from US patent 2016 / 0307169 A1.

[0023] WO 2013 / 095145 A1 concerns a process for recycling waste rubber, which includes the steps of pyrolyzing waste rubber in a two-stage process to obtain a carbon material and the subsequent grinding of the carbon material thus obtained.

[0024] WO 2020 / 020810 A1 discloses a filler comprising recovered carbon black with an iodine adsorption number, measured according to ASTM D-1510-17, between 95 g / kg and 160 g / kg, preferably between 115 g / kg and 140 g / kg.

[0025] WO 2020 / 082050 A1 describes a process for converting tires into pelletized, recovered carbon black, comprising the following process steps: cutting a set of tires into a volume of tire rubber segments, the set of tires being selected from a group comprising an agricultural tire, a commercial vehicle tire, and a passenger car tire; thermally depolymerizing the volume of tire rubber segments in a pyrolytic reactor to a volume of Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0026] 5. Carbon-containing material; the comminution of the volume of carbon-containing material; the removal of agglomerates larger than the maximum agglomerate diameter from the volume of carbon-containing material; the mixing of the volume of carbon-containing material with a binder in a mixer over a first period, the mixer inducing the formation of a set of pellets with different pellet diameters; the drying of the set of pellets in a dryer to a specified moisture content; and the removal of a first subset of pellets larger than a maximum pellet size from the set of pellets.

[0027] CN 213012686 U discloses a device for cracking carbon black from scrap tires, comprising a cracking furnace and a heat treatment furnace. The cracking furnace consists of an inner and an outer furnace drum, the outer drum surrounding the inner drum. A material inlet is located at one end of the inner drum, and a material outlet is located at the other end of the outer drum. A gas-phase lysate outlet and a solid-phase lysate outlet are provided at the other end of the casing.

[0028] CN 107236329 A concerns a process for producing carbon black from waste tires and refers to a process for using waste tires.The process for producing carbon black from used tires comprises the following steps: classification of the used tires and bead cutting; feeding the treated tires into a crusher, multi-stage shredding to obtain granulate products and recovery of the dust generated during the shredding process using dust removal equipment; feeding the granulated used tire raw materials and the recovered dust into a magnetic separator and removing iron impurities to obtain pure rubber blocks after iron removal; grinding the pure rubber blocks in a grinding machine, carrying out a reaction in a pyrolysis furnace and recovering the carbon residues generated during pyrolysis; and carrying out magnetic separation of the carbon residues generated during pyrolysis, removing iron-containing steel wire remnants and grinding the recovered Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025.

[0029] 6

[0030] Raw carbon residues.

[0031] A process for recycling used tires is known from US Patent 2022 / 0251392 A1. The process includes, among other things, the following pyrolysis steps: feeding the shredded material into a rotating horizontal cylindrical thermolysis reactor surrounded by an outer chamber; closing the reactor and introducing an inert gas to create an oxygen-free atmosphere; indirect heating of the reactor with gases from a combustion chamber by directing the gases into the outer chamber; gradual increase of the temperature from room temperature and maintenance in a range between 250°C and 350°C for a period of 1 to 4 hours, during which the water, all lighter hydrocarbons, and some of the heavier hydrocarbons are gasified; and a further increase of the temperature to over 450°C for a period of 2 to 4 hours to achieve the gasification of the heavier hydrocarbons that are still in the liquid state.

[0032] The use of recovered industrial carbon black for rubber compounds in tire manufacturing is known.

[0033] WO 2023 / 249020 A1 discloses a tire comprising a pair of sidewall rubbers, a carcass cord lining rubber, a breaker lining rubber and an inner liner rubber, wherein: at least one of the rubbers contains recycled carbon black; at least one rubber element forming the tire contains oil, wherein if the total amount (g) of recycled carbon black is A and the total amount (g) of oil contained in the tire is B, A and B satisfy the expression (A / B)x100>1.

[0034] WO 2024 / 074784 A1 concerns a tire comprising two beads, at least one of which comprises a rubber composition based on:

[0035] - at least one elastomer;

[0036] - 60 to 100 phr reinforcing fillers, including 15 to 70 phr pyrolytic carbon black and 15 to 60 phr carbon black with a total carbon black and pyrolytic carbon black content in the area Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0037] 7 of 60 to 90 phr; and

[0038] - a networking system.

[0039] In WO 2023 / 077082 A1, a silica-reinforced

[0040] A rubber composition containing untreated recovered carbon black is disclosed.

[0041] WO 2022 / 202698 A1 describes a rubber composition for tires comprising a diene-based rubber, carbon black and recycled carbon black, wherein the carbon black has a specific nitrogen adsorption surface area N2SA of 30-90 m2 / g and a DBP oil absorption of 70-140 m 1 / 100 g, the recycled carbon black has a specific nitrogen adsorption surface area N2SA of 65-95 m2 / g and a DBP oil absorption of 75-105 ml / 100 g, the total amount of carbon black, which is the sum of the carbon black and the recycled carbon black, is 30-130 parts by mass per 100 parts by mass of the diene-based rubber and the proportion of recycled carbon black in the total amount of carbon black is 3-30% by mass.

[0042] EP 3 327 079 B1 discloses a rubber compound for the inner layer or tube of vehicle pneumatic tires, which contains the following components:

[0043] - at least one butyl rubber and / or halobutyl rubber and

[0044] - a filler system with 55 wt.% or more of at least one pyrolysis carbon black as a proportion of the total amount of fillers contained, wherein the filler system contains up to 45 wt.% of at least one inactive inorganic filler, wherein the sums of the amounts of fillers contained amount to 100 wt.%, wherein calcium carbonate and / or platelet-shaped fillers, such as layered silicates and / or dry mixture compounds, containing at least 25 wt.% of at least one delaminated aluminohydrosilicate modification, wherein the delaminated aluminohydrosilicate modification has a two-layer lattice, are / are contained as at least one inactive inorganic filler.

[0045] German patent DE 10 2016 200 950 A1 describes a rubber compound for the inner layer or tube of pneumatic vehicle tires, comprising at least one butyl rubber and / or halobutyl rubber and at least one pyrolysis carbon black. Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0046] 8

[0047] WO 2016 / 105932 A1 discloses a rubber compound with a rubber elastomer, between 1 and 75 phr of vegetable oil and between 1 and 80 phr of recovered industrial carbon black.

[0048] EP 3 237 530 B1 relates to a tire rubber composition comprising a rubber elastomer comprising at least 50 phr of natural rubber or natural polyisoprene; a reinforcing filler component and an oil component; the reinforcing filler component comprising 1 to 80 phr of recycled carbon black; the oil component comprising 1 to 8 phr of vegetable oil; and recycled particulate rubber in an amount of 1 phr to 75 phr; wherein the composition contains no more than 10 phr of any oil other than vegetable oil and no more than 5 phr of any carbon black other than recycled carbon black, and wherein the recycled carbon black constitutes at least 75% by weight of the reinforcing filler component.

[0049] A disadvantage of these known processes is that the produced rCB exhibits poor reinforcement properties, particularly when used in rubber compounds. Poor aging properties due to insufficient pyrolysis or partial graphitization of the material caused by excessively high pyrolysis temperatures can lead to low in-rubber performance. Similarly, the permeability of rubber compounds used for inner tire layers can be increased and thus degraded. These properties, along with higher sulfur and ash content and lower carbon content, result in lower exchange rates in vCB-rCB blends as rubber fillers and may necessitate compensation measures.

[0050] This is related to the often unsorted raw material for tires from various sources, which differ in age and composition. Furthermore, the current state of the art regarding pyrolysis involves the production of carbon black in two-stage rotary kilns or expensive and technically demanding screw reactors, which often require high temperatures and long reaction times. These processing problems also lead to a Continental Tires Germany GmbH 24057-P-WO / 25.11.2025

[0051] 9. The high ash content (inorganic and especially organic) results in a low carbon content, which further limits the performance of the recovered carbon black for use in tires. The following problems therefore exist in the product:

[0052] • Particle sizes above 11 pm due to inadequate grinding technology,

[0053] • Heterogeneous primary particle distribution due to unsorted tire raw material,

[0054] • Excessively high and fluctuating proportion of inorganic components (ash) due to unsorted tire raw material with a high silica content,

[0055] • Low and fluctuating toluene transmission due to insufficient and uneven pyrolysis reaction,

[0056] • High levels of volatile components due to insufficient and uneven reaction,

[0057] • High proportion of polycyclic aromatic hydrocarbons (PAHs) due to insufficient and uneven reaction.

[0058] This results in an industrial carbon black with limited in-rubber performance, which is not suitable for substituting conventional carbon blacks of types N660 and N550 and therefore has only limited areas of application.

[0059] Rubber compounds for vehicle tires without rCB are known from the state of the art.

[0060] WO 2010 / 034592 A1 relates to a rubber compound with the following known composition: 30 to 100 phr of at least one halobutyl rubber, and 0 to 70 phr of at least one further diene rubber, and 5 to 100 phr of a dry mixture compound containing at least 25% of at least one delaminated aluminohydrosilicate modification, wherein the delaminated aluminohydrosilicate modification has a two-layer lattice, and 10 to 100 phr of at least one carbon black with an STSA surface area according to ASTM-D 6556 of 10 to 60 m². 2 / g and a DBP number according to ASTM-D 2414 of 50 to 160 mL / 100 g, and 3 to 20 phr of at least one mineral oil plasticizer and other additives.

[0061] DE10 2014 212 486 A1 describes a rubber compound with the following designation: Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0062] 10

[0063] Composition:

[0064] - 90 to 100 phr of at least one styrene-butadiene rubber and

[0065] - 0 to 10 phr of at least one other diene rubber and

[0066] - 35 to 200 phr of at least a layered silicate and / or a dry mixture compound containing at least 25 wt.% of at least one delaminated aluminohydrosilicate modification, wherein the delaminated aluminohydrosilicate modification has a two-layer lattice.

[0067] The invention is based on the objective of providing a rubber compound with higher reinforcement potential based on selected raw materials and specific pyrolysis conditions. A further objective of the present invention is to provide a vehicle pneumatic tire that has a rubber compound with a rCB exhibiting similar or better properties than a vCB of types N660 and N550.

[0068] The rCB is intended as a sustainable alternative to reinforcing filler material for rubber compounds in tire applications, including the N300-N900 series. Applications include the inner layer, sidewall, tread surface, and tire components for special tire designs such as heavy-duty tires, solid rubber tires, bias-ply tires, two-wheel tires, and agricultural tires.

[0069] The problem of the present invention is solved by a rubber compound containing the following components:

[0070] • at least one diene rubber

[0071] • a recovered industrial carbon black with an organic residue content of 0-5% and a carbon content of 70-85% and an inorganic ash content of 15-30%, wherein the process for producing the recovered industrial carbon black comprises the following steps:

[0072] • Selecting used tires,

[0073] • Shredding of used tires into used tire granules,

[0074] • Pyrolysis of the waste tire granulate with a residence time between 2 and 4

[0075] Hours at a material temperature between 550°C and 750°C, Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0076] 11

[0077] • Grinding of the recovered industrial soot,

[0078] • Wet pelletizing of the ground, recovered industrial carbon black.

[0079] Diene rubbers are rubbers that are formed by polymerization or copolymerization of dienes and / or cycloalkenes and thus have C=C double bonds either in the main chain or in the side groups.

[0080] The diene rubber is preferably selected from the group consisting of natural polyisoprene and / or synthetic polyisoprene and / or epoxidized polyisoprene and / or butadiene rubber and / or butadiene-isoprene rubber and / or solution-polymerized styrene-butadiene rubber and / or emulsion-polymerized styrene-butadiene rubber and / or styrene-isoprene rubber and / or liquid rubbers with a molecular weight Mw of greater than 20,000 g / mol and / or butyl rubber and / or halobutyl rubber and / or polynorbornenes and / or isoprene-isobutylene copolymer and / or ethylene-propylene diene rubber and / or nitrile rubber and / or chloroprene rubber and / or acrylate rubber and / or Fluorocarbon rubber and / or silicone rubber and / or polysulfide rubber and / or epichlorohydrin rubber and / or styrene-isoprene-butadiene terpolymer and / or hydrogenated acrylonitrile butadiene rubber and / or hydrogenated styrene-butadiene rubber.

[0081] Halobutyl rubber is, for example, BIIR or CIIR.

[0082] An exemplary rubber compound has the following composition: 30 to 100 phr of at least one halobutyl rubber, and 0 to 70 phr of at least one other diene rubber, and 5 to 200 phr of a dry mixture compound containing at least 25% of at least one delaminated aluminohydrosilicate modification, wherein the delaminated aluminohydrosilicate modification has a two-layer lattice, and 10 to 100 phr of at least one recovered industrial carbon black produced by this process, and 3 to 20 phr of at least one mineral oil plasticizer and other additives.

[0083] Another example of a rubber compound has the following composition: Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0084] 12

[0085] - 30 to 100 phr of at least one styrene-butadiene rubber and

[0086] - 0 to 70 phr of at least one other diene rubber and

[0087] - 0 to 200 phr of conventional industrial carbon black and / or conventional silica

[0088] - and 10 to 100 phr of at least one recovered industrial carbon black produced using this method.

[0089] Conventional silica can refer to the silicas known to experts as fillers for tire rubber compounds. However, it is particularly preferred to use finely dispersed, precipitated silica with a nitrogen surface area (BET surface area) (according to DIN ISO 9277 and DIN 66132) of 35 to 400 m². 2 / g, preferably from 35 to 350 m 2 / g, especially preferably from 85 to 320 m 2 / g and especially preferred from 120 to 235 m 2 / g, and a CTAB surface area (according to ASTM D 3765) of 30 to 400 m² 2 / g, preferably from 30 to 330 m 2 / g, especially preferred from 80 to 300 m 2 / g and especially preferred from 115 to 200 m 2 / g, exhibits.

[0090] Suitable silicas include, for example, those of the Ultrasil® VN3 type (trade name) from Evonik, silicas with a comparatively low BET surface area (such as Zeosil® 1115 or Zeosil® 1085 from Solvay), and highly dispersible silicas, so-called HD silicas (e.g., Zeosil® 1165 MP from Solvay). Silicon dioxide obtained from the residue of rice hull combustion can also be used. Preferably, the silica has a CTAB number of more than 130 m. 2 / g on.

[0091] If the rubber compound contains conventional silicas, it may also contain a coupling agent in the form of a silane or an organosilicon compound. One or more different silane coupling agents can be used in combination. The rubber compound may therefore contain a mixture of different silanes.

[0092] All silane coupling agents suitable for use by specialists are listed in Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025.

[0093] Thirteen silane coupling agents known from the prior art are used in rubber compounds. Such coupling agents are bifunctional organosilanes that possess at least one alkoxy, cycloalkoxy, or phenoxy group as a leaving group on the silicon atom and that, as a further functionality, exhibit a group which, if necessary after cleavage, can undergo a chemical reaction with the double bonds of the polymer. The latter group can be, for example, the following chemical groups: -SCN, -SH, -NH2, or -Sx- (with x = 2 to 8).

[0094] Various reactor types can be used for pyrolysis. These different reactor types have advantages and disadvantages in terms of energy efficiency, temperature stability, miscibility, and particle, pyrolysis oil, and gas properties. Possible reactor types include, for example, fixed-bed, (mechanically) mixed-bed (auger-type, moving screw), and fluidized-bed reactors. A pyrolysis reactor can also be a vertical moving-bed reactor with several pyrolysis zones arranged one above the other. This type of reactor may incorporate means for indirect electrical heating of the inner tube and a slot system on the outer surface of the internal components to extract pyrolysis vapors by negative pressure. The pyrolysis of waste tires produces gaseous products (pyrolysis gas), liquid products or products that condense after pyrolysis (pyrolysis oil), and solid products (pyrolysis coke).Pyrolysis coke is the recovered industrial soot with its organic and inorganic residues.

[0095] In addition to conventional parameters such as reaction time, heating rate, and reaction temperature, the rCB particle size can be influenced by "fast" and "flash" pyrolysis processes. After pyrolysis, the recovered industrial carbon black can be processed for use in rubber applications by mechanical and / or chemical post-treatment and pelletizing. The type of post-treatment depends on the specific rubber application. Properties similar to those of conventional industrial carbon blacks (virgin carbon black (vCB)) of type N300 - N772 are preferred in rubber compounds for tire applications. The properties preferably resemble those of Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0096] 14 of the rCB the properties of vCB of types N772, N660 or type N550.

[0097] In addition to the pyrolysis process (time / temperature), the ratios of carbon content, inorganic ash, and organic residues, as well as the particle size, are relevant for the reinforcing properties of the rubber, which can also be controlled via defined feedstocks (the so-called tire feedstock). The following is a basic characterization of the rubber properties based on ASTM Recommendation 3191, on which this recipe is based:

[0098] It is known to experts that these rubber compounds are suitable for evaluating property profiles for applications in various tire components such as tread surfaces, sidewalls or tire components for special types of tires such as heavy-duty tires, solid rubber tires, bias-ply tires, agricultural tires, two-wheel tires, etc.

[0099] Further rubber formulations for more specific tire applications are presented in the respective Tables 3 to 6, in particular the application in rubber compounds for the inner layer of vehicle pneumatic tires.

[0100] The used tires can be, for example, truck tires, car tires, or a mixture of both. The tires can be sorted by type. Used tire granulate is produced from the tires. This granulate is manufactured using a granulating and separating plant in which whole or pre-cut tires are processed into rubber granulate separated from textiles and steel. The production of used tire granulate can be carried out, for example, using an Eldan Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0101] 15

[0102] The process is carried out using a tire cleaning plant type E5000T and a steel cleaning plant type IL4000S. The rubber granulate preferably has a purity of >99.5% (ASTM D8268) and a particle size of 0.5–6.0 mm (ASTM D5644). Industrial carbon black can be obtained from the pyrolysis process with a residence time of 2 to 4 hours at a material temperature between 550°C and 750°C. The recovered industrial carbon black is then ground using a jet mill, in particular a jet mill (Hosokawa type 100 AFG or type 800 TDG), and the powder is wet pelletized (Lödige, CoriMix type CM 80 or Mars Minerals, type 26D100Li-SS).

[0103] The recovered industrial carbon black produced using this process has, among other things, the following advantages:

[0104] • Improvement of the properties in the rubber compound (Ref. N300-N900 (ASTM D1765)),

[0105] • Defined particle sizes through controlled grinding,

[0106] • More homogeneous primary particle distribution due to the defined tire raw material,

[0107] • Defined and constant proportion of inorganic and organic components (ash) based on a defined tire raw material,

[0108] • High and constant toluene transmission due to optimal and homogeneous reaction,

[0109] • Low and constant levels of volatile components due to optimal and homogeneous reaction,

[0110] • Low PAHs due to optimal and homogeneous reaction.

[0111] Advantages include the possibility of completely replacing conventional carbon black with rCB, improved rolling resistance, improved aging behavior compared to reference, improved permeability performance, and processing advantages.

[0112] Within the scope of the present invention, the term "vehicle pneumatic tires" refers to both tubeless vehicle pneumatic tires with an inner layer (also called inner liner) and vehicle pneumatic tires with an inner tube. Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0113] 16

[0114] This includes all pneumatic vehicle tires known to those skilled in the art, such as passenger car tires, truck tires, and two-wheeler tires – use is in tubeless pneumatic vehicle tires. A typical inner layer is used for truck applications, but it is also suitable for passenger car and motorcycle applications (see Tables 4-6 and Table 3 for ASTM 3191).

[0115] Additionally, the composition of the used tires as starting material can be used to control the proportion of sulfur, ZnO and metals in the recovered industrial carbon black.

[0116] The rubber compound according to the invention is produced according to a process customary in the rubber industry, in which a base mixture containing all components except the vulcanization system (sulfur and vulcanization-influencing substances) is first produced in one or more mixing stages. The finished compound is then produced by adding the vulcanization system in a final mixing stage. Substances that can also have a vulcanization-retarding effect (such as MBTS) can also be added in one of the base mixing stages. The total amount of added rCB can be distributed across different mixing stages. The finished compound is further processed, for example, by extrusion or calendering and formed into the desired shape.Processes for the manufacture of vehicle tires, in particular for the manufacture of extrudates and calendered semi-finished products, for example the inner layer of tubeless tires and tubes of tubed tires, are generally known to those skilled in the art.

[0117] The following advantages have resulted from using recovered industrial carbon black for an inner layer in the manufacture of a tire for a truck, car, van or motorcycle:

[0118] • A higher Mooney viscosity leads to greater stiffness of the raw material, which is advantageous for handling and dimensional stability of the tire blanks during tire production. On the other hand, a higher Mooney viscosity has a negative impact on the extrusion process, as it [Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025]

[0119] 17. The risk of scorching increases, which usually leads to a reduction in extrusion speed. However, in combination with the new material, the scorching-related property t10 is longer, the bonding process is slower, which again reduces the risk of scorching. Thus, the new rCB surprisingly offers advantages for the production of tire blanks without limiting extrusion productivity.

[0120] The cured materials exhibit a slightly reduced hardness (RT) with a slightly improved (higher) rebound at 70°C. This already indicates an advantage in terms of rolling resistance. This is confirmed by the E' and tan delta values ​​at 55°C and 70°C, which are commonly used as indicators of rolling resistance. The lower the tan delta, the greater the advantage in rolling resistance. On the other hand, the modulus (stiffness) of the material remains at a similar level. It can therefore be expected that a tire equipped with an inner layer made of recovered industrial carbon black will offer advantages in terms of fuel consumption and environmental impact.

[0121] • The strength properties are acceptable for the intended application as an inner layer.

[0122] To minimize the amount of air escaping through the sealing area between the tire and rim, it can be advantageous to use a material that adapts best to any irregularities in the rim and tire. An inner layer with high compression set can be beneficial in this regard. The compression set of the inner layer with the new material is significantly higher than that of the reference material.

[0123] • The gas permeability can be considered comparable and sufficient for the intended application.

[0124] • Overall, the recovered industrial carbon black offers advantages for product performance without disadvantages that would restrict its use for the desired application.

[0125] A preferred embodiment of the invention consists in the pyrolysis taking place in a single-stage vertical moving-bed reactor. Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0126] 18

[0127] The single-stage vertical moving-bed reactor can, for example, be a thermal reactor with an inlet section, a heating zone middle section, and an outlet section, all arranged vertically one above the other. A suction pipe is centrally located within the heating zone middle section of the thermal reactor. The surface of this pipe has numerous bores and / or slots for venting the resulting short-chain hydrocarbon vapors. Conical bells are mounted one above the other onto the suction pipe. The outer shell of the heating zone middle section features a multitude of radially arranged heating plates, offset from each other in relation to the stacked heating levels.

[0128] Advantageously, the use of rCB after a single-stage diffusion sedimentation-driven pyrolysis process under temperature and reaction time control allows for the minimization of the organic residue in particular, which, together with the coke residues, significantly influences the reinforcing properties, for example in rubber applications.

[0129] A preferred embodiment of the invention consists in the waste tires being a mixture of sorted truck waste tires and sorted passenger car waste tires in a ratio of 60:40 (w / w%), wherein the pyrolysis of the waste tire granulate takes place with a residence time of 2 to 3 hours at a material temperature of 650°C and 750°C.

[0130] A particularly preferred embodiment of the invention consists in the waste tires being sorted truck waste tires, wherein the pyrolysis of the waste tire granulate takes place with a residence time of 3 to 4 hours at a material temperature of 550°C and 650°C.

[0131] The recovered industrial carbon black preferably has a particle size between 8 and 10 pm according to ASTM WK87480.

[0132] Advantageously, the recovered industrial carbon black exhibits an organic composition. Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0133] 19

[0134] Residue content of 0-5% and a carbon content of 70-85% as well as an inorganic ash content of 15-30%.

[0135] Another embodiment of the invention consists in the amount of recovered industrial carbon black contained in the rubber mixture being 10 to 90 phr, preferably 30-70 phr.

[0136] Another embodiment of the invention consists in the rubber mixture comprising 0 to 200 phr, preferably 5-185 phr, of conventional industrial carbon black and / or conventional silica.

[0137] Another embodiment of the invention consists in the rubber mixture containing 0 to 70 phr, preferably 30-60 phr of a dry mixture compound.

[0138] The rubber compound can contain 0 to 70 phr of a dry mix compound containing at least 25% of at least one delaminated aluminohydrosilicate modification, wherein the delaminated aluminohydrosilicate modification has a two-layer lattice. The percentage refers to the total weight of the dry mix compound. The two-layer lattice of the delaminated aluminohydrosilicate modification is preferably a dioctahedral two-layer lattice. This rubber compound is particularly advantageous for the production of an inner layer of a vehicle tire.

[0139] The dry mixture has a water content of 0 to 2%, preferably 0 to 1%. This water content is mainly, but not exclusively, due to the presence of water of crystallization.

[0140] The dry compound may additionally contain at least 40% of a di- or trioctahedral three-layer silicate from the phyllosilicate group and / or at least 10% of a crystalline quartz modification or amorphous quartz. The percentage refers to the total weight of the dry compound. Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0141] 20

[0142] Regarding the classification of di- or trioctahedral three-layer silicates, see, for example, Matthes, Mineralogie, Springer-Lehrbuch, 3rd edition, 1990, pp. 129 ff. The dry mixture compound is described in EP 2 331 349 A1.

[0143] Particularly good fatigue resistance is observed when the delaminated aluminohydrosilicate modification has a CTAB surface area according to ASTM D 3765 of 10 to 40 m² / g, a BBT surface area according to DIN 66131 and DIN 66132 of 10 to 20 m² / g, an average particle size of 5 to 15 µm, and a D50 particle size of 3 to 9 µm. These values ​​were determined by laser diffraction. The aspect ratio can be determined from the size and shape of the particles. It has proven advantageous for the aspect ratio, i.e., the ratio of particle length to width (L / W), to be between 1.0 and 2.8, preferably between 1.0 and 2.0, and most preferably between 1.2 and 1.5. To determine the aspect ratio, the particles were measured using an automated image analysis method with a CCD detector, Sysmex FPIA-3 000 from Malvern Instruments Ltd.For further details regarding the measurement analysis, please refer to the relevant data sheets and information from the manufacturer mentioned, some of which are also available on their website.

[0144] Kaolin, for example, can be used as a dry compound. Furthermore, the rubber mixtures can contain other mineral fillers such as ground calcium carbonate or silicon dioxide.

[0145] The present invention also relates to a vehicle pneumatic tire comprising at least one rubber compound according to the invention.

[0146] According to a preferred embodiment of the invention, the invention is a tubeless pneumatic vehicle tire which has at least one rubber compound according to the invention at least in the inner layer.

[0147] According to a further preferred embodiment of the invention, it is a tube-type tire which incorporates at least one of the invention's features. Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0148] 21

[0149] The rubber compound is present at least in the hose.

[0150] The present invention also relates to a hose for use in a tube tire, which contains at least one rubber compound according to the invention, including preferred embodiments.

[0151] The invention is described in more detail below using two exemplary embodiments. rCB Type 1

[0152] Industrial carbon black type 1 is produced using a vertical moving bed reactor according to the Pyrum design (WO 2010 / 127664 A1 , WO 2012 / 092924 A1 ) by using a granulate mixture with a purity >99.5% (ASTM D8268) and a grain size of 0.5 - 6.0 mm (ASTM D5644) from sorted truck tires (solid tires) and sorted passenger car tires (solid tires) in a ratio of 60:40 (w / w%) with a residence time of 2 to 3 hours at a material temperature of 650°C to 750°C. The raw rCB is then milled using a jet mill (Hosokawa Type 100 AFG and / or Hosokawa Type 800 TDG) and the powder is wet pelletized (Lödige, CoriMix Type CM 80 and / or Mars Minerals, Type 26D100Li-SS). Advantageously, the in-rubber performance of rCB Type 1 is comparable to that of vCB Type N660. In particular, rCB Type 1 exhibits in-rubber performance with properties intermediate between those of vCB Types N772 and N660.

[0153] Using a vertical moving bed reactor of the Pyrum design (WO 2010 / 127664 A1, WO 2012 / 092924 A1), raw rCB type 2 is produced by employing pure, graded truck tire granulate (solid tires) with a purity >99.5% (ASTM D8268) and a particle size of 0.5–6.0 mm (ASTM D5644) for a residence time of 3 to 4 hours at a material temperature of 550°C to 650°C. The raw rCB is then milled using a counterjet mill (Hosokawa type 100 AFG or type 800 TDG) and the powder is wet pelletized (Lödige, Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025).

[0154] 22

[0155] CoriMix type CM 80 or Mars Minerals, type 26D100Li-SS). Advantageously, the in-rubber performance of rCB type 2 corresponds to that of vCB type N550. In particular, rCB type 2 exhibits in-rubber performance with properties intermediate between those of vCB types N660 and N550.

[0156] Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0157] 23

[0158] Table 1: Physicochemical properties of rCB Basic, rCB Type 1 & rCB Type 2: Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0159] 24

[0160] Reclaimed carbon black of types rcB Type 1 and rCB Type 2 can be described based on the properties of the rubber compound containing the rCB, particularly for tire manufacturing. The properties of types rCB Basic, rCB Type 1, and rCB Type 2 are compared with those of state-of-the-art carbon black of types vCB N660 and vCB N550. rCB Basic is the recovered carbon black previously obtained using the Pyrum process (WO 2010 / 127664 A1, WO 2012 / 092924 A1). The comparison is made with the properties in the rubber compound according to ASTM 3191 (ESBR).

[0161] Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0162] 25

[0163] Table 2: Properties of the ASTM 3191 rubber compound of types rCB

[0164] Basic, rCB Type 1, rCB Type 2 Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0165] 26

[0166] *1 measured at

[0167] Room temperature (RT)

[0168] *2 Maximum (lower = better)

[0169] *3 Classification of industrial carbon blacks according to ASTM D1765

[0170] Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0171] 27

[0172] Tables 3 to 6 show various recipes for rubber compounds. Tables 4 to 6 show recipes for rubber compounds for the inner layer of a pneumatic tire (IL 1, IL 2, IL 3). The rubber compound is produced after vulcanization from the

[0173] Rubber compound obtained. The relative aging processes of these rubber compounds are shown in Table 7.

[0174] Table 3: ASTM 3191 Comparison of vCB types N772, N660 and N550 with rCB type 1 and rCB type 2 Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0175] 28

[0176] Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0177] 29

[0178] Table 4: Recipe for a rubber compound for the inner layer of an pneumatic tire (IL 1 ) Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0179] 30

[0180] The recipe from Table 4 can also contain up to 30 phr of recycled butyl rubber based on used tires or hoses. The diene rubber is preferably composed of 100% halobutyl rubber.

[0181] Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0182] 31

[0183] Table 5: Recipe for a rubber compound for the inner layer of a pneumatic tire (IL 2) Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0184] 32

[0185] The recipe from Table 5 can also contain up to 30 phr of butyl regenerate based on used tires or hoses. The diene rubber is preferably a mixture of halobutyl rubber and NR, with halobutyl rubber representing the largest proportion.

[0186] Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0187] 33

[0188] Table 6: Recipe for a rubber compound for the inner layer of a pneumatic tire (IL 3) Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0189] 34

[0190] The recipe from Table 6 can also contain up to 30 phr of butyl regenerate based on used tires or hoses. The diene rubber is preferably a mixture of halobutyl rubber, natural rubber, and SBR, with halobutyl rubber representing the largest proportion.

[0191] The mixtures were prepared under standard conditions in two stages using a laboratory tangential mixer. Test specimens were produced from all mixtures by vulcanization, and material properties typical for the rubber industry were determined using these specimens. The following test procedures were applied to the specimens:

[0192] • Shore A hardness at room temperature (RT) and 70 °C according to ASTM D2240

[0193] • Rebound elasticity at room temperature and 70 °C according to ASTM D7121

[0194] • Tensile strength, elongation at break and stress value at 300% (module 300) static strain at room temperature according to ASTM D412

[0195] • Air permeability according to ASTM D814 at 70 °C air temperature Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0196] 35

[0197] The higher the rebound elasticity at 70 °C, the lower the energy loss and therefore the better the rolling resistance.

[0198] The lower the gas permeability (permeability), the better the airtightness. Furthermore, other properties, such as tensile strength, stiffness, and hardness, remain at a comparable level.

[0199] A vehicle pneumatic tire containing the rubber compound according to the invention in the inner layer or in the tube thus exhibits optimized rolling resistance with comparable other properties and good air tightness.

[0200] Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025

[0201] 36

[0202] Table 7: Relative aging effect referenced to vCB types N772 (IL 1 ) or N660 (IL 2 / IL 3), underlying rubber compounds in Table 4 (IL 1 ), Table 5 (IL 3) and Table 6 (IL 2)

[0203] The relative values ​​become smaller, which corresponds to better aging performance.

Claims

Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025 37 REQUIREMENTS 1. Rubber compound for vehicle tires, wherein the rubber compound contains the following components: • at least one diene rubber • a recovered industrial carbon black with an organic residue content of 0-5% and a carbon content of 70-85% and an inorganic ash content of 15-30%, wherein the process for producing the recovered industrial carbon black comprises the following steps: • Selecting used tires, • Shredding of used tires into used tire granules, • Pyrolysis of the waste tire granulate with a residence time of between 2 and 4 hours at a material temperature between 550°C and 750°C, • Grinding of the recovered industrial soot, • Wet pelletizing of the ground, recovered industrial carbon black.

2. Rubber compound according to claim 1, characterized in that the pyrolysis takes place in a single-stage vertical moving bed reactor.

3. Rubber compound according to claim 1 or 2, characterized in that the waste tires are a mixture of sorted truck waste tires and sorted passenger car waste tires in a ratio of 60:40 (w / w%), wherein the pyrolysis of the waste tire granulate takes place with a residence time of 2 to 3 hours at a material temperature of 650°C and 750°C.

4. Rubber compound according to claim 1 or 2, characterized in that the waste tires are sorted truck waste tires, wherein the pyrolysis of the waste tire granulate takes place with a residence time of 3 to 4 hours at a material temperature of 550°C and 650°C. Continental Reifen Deutschland GmbH 24057-P-WO / 25.11.2025 38 5. Rubber compound according to one of the preceding claims, characterized in that the recovered industrial carbon black has an organic residue content of 0-5% and a carbon content of 70-85% as well as an inorganic ash content of 15-30%.

6. Rubber compound according to one of the preceding claims, characterized in that the amount of recovered industrial carbon black contained in the rubber compound is 10 to 90 phr.

7. Rubber compound according to one of the preceding claims, characterized in that the rubber compound comprises 0 to 200 phr of conventional industrial carbon black and / or conventional silica.

8. Rubber compound according to one of the preceding claims, characterized in that the rubber compound comprises 0 to 70 phr of a T contains dry mixed compound.

9. Vehicle tire comprising at least one rubber compound according to any one of claims 1 to 8.

10. Vehicle tire according to claim 9, characterized in that it is a pneumatic vehicle tire.

11. Vehicle pneumatic tire according to claim 10, wherein it is a tubeless vehicle pneumatic tire and it has the rubber compound at least in the inner layer.

12. Vehicle pneumatic tire according to claim 10, wherein it is a tube tire and it has the rubber compound at least in the tube.

13. Tube for use in a tubular tire, comprising at least one rubber compound according to any one of claims 1 to 8.

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