Process for preparing a rubber compound in the liquid phase

A continuous process for forming a coagulum by mixing elastomer latex with pyrolysis carbon black dispersion addresses dispersion and mechanical property issues, ensuring effective incorporation in elastomeric compositions.

WO2026068421A1PCT designated stage Publication Date: 2026-04-02MICHELIN & CO (CIE GEN DES ESTAB MICHELIN)
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Patent Information

Authority / Receiving Office
WO · WO
Patent Type
Applications
Current Assignee / Owner
Filing Date
2025-09-23
Publication Date
2026-04-02

AI Technical Summary

Technical Problem

Existing methods for incorporating pyrolysis carbon black as a substitute for virgin carbon black in elastomeric compositions for rubber products face issues of poor dispersion and reduced mechanical properties, requiring additional processing steps and costly materials like silica.

Method used

A continuous process for producing a coagulum by contacting elastomer latex with an aqueous dispersion of pyrolysis carbon black in a coagulation reactor, forming a coagulum with good dispersion and maintaining mechanical properties without additional agents.

Benefits of technology

Achieves effective dispersion of pyrolysis carbon black in the elastomeric matrix, maintaining fatigue resistance and mechanical properties while reducing environmental impact and costs.

✦ Generated by Eureka AI based on patent content.

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Abstract

The invention relates to a process for continuously obtaining a coagulum based on at least one elastomer and a reinforcing filler, said process comprising the following steps: a) continuously supplying a first stream of a fluid consisting of an elastomer latex, b) continuously supplying a second stream of a fluid consisting of an aqueous dispersion of a reinforcing filler comprising at least one pyrolysis carbon black, c) bringing said first stream into contact with said second stream in a mixing zone of a coagulation reactor, wherein the continuous contacting induces the formation of a coagulum of the elastomer latex with the aqueous dispersion of the reinforcing filler, d) continuously recovering said coagulum obtained in the preceding step.
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Description

Process for preparing a rubbery mixture in liquid phase Description FIELD OF INVENTION The present invention relates to the field of masterbatches, particularly those based on recycled raw materials, and their process for obtaining them in the liquid phase. Masterbatches are notably used for the manufacture of elastomeric compositions, particularly those intended for the production of rubber articles such as pneumatic and non-pneumatic tires. STATE OF THE ART In recent years, limiting the environmental impact of the manufacture of rubber products, particularly pneumatic or non-pneumatic tires, and their use has become a major issue for manufacturers in the sector. Research and development initiatives to produce rubber products such as pneumatic and non-pneumatic tires incorporating elastomeric compositions based on recycled or bio-based materials have proliferated. For example, it has been proposed to use pyrolysis carbon black as a total or partial substitute for conventional carbon black (also called virgin carbon black) used as a reinforcing filler in the elastomeric compositions of pneumatic and non-pneumatic tires; conventional carbon black being obtained from non-renewable raw materials of petroleum or fossil origin such as tars, oils, and / or gases. However, this partial or total substitution of these conventional carbon blacks by pyrolysis carbon blacks is accompanied by a number of disadvantages, including poor dispersion in the elastomeric matrix and a reinforcing power different from that of virgin carbon blacks. However, it is known that poor dispersion of a reinforcing filler within the elastomeric matrix of a compound results in inferior mechanical properties of that compound. This reduction in mechanical properties is unacceptable for a manufacturer of rubber products, particularly for a manufacturer of pneumatic or non-pneumatic tires. Several solutions have been considered to address the problem of the different mechanical properties of pyrolysis carbon blacks from recycling as a partial or total replacement of virgin carbon blacks in an elastomeric composition. For example, document WO2016 / 16869A1 proposes to solve this problem by covering at least partially the external surface of said pyrolysis carbon black with an external layer of silica. Another solution described in document W02019 / 002437A1 involves activating the surface of these pyrolysis carbon blacks by a specific chemical treatment. Document EP3173251 Al proposes a solution for preparing elastomeric compositions based on oxidized pyrolysis carbon blacks and adding a silane coupling agent to obtain the desired mechanical properties. These solutions have the drawback of requiring one or more additional processing steps before using pyrolysis carbon black in a rubber compound. These processes are costly for manufacturers: they require new equipment, time, energy, and also use other raw materials such as silica. Therefore, there remains a need for elastomeric compounds, particularly for the manufacture of rubber products, especially pneumatic and non-pneumatic tires, to limit the environmental impact of their production and use while ensuring both good dispersion of the reinforcing compound and the maintenance of mechanical properties. The present invention addresses this need. Surprisingly, the applicant discovered that it is possible to obtain elastomeric compositions comprising a reinforcing filler from a recycling process, in particular pyrolysis carbon black, exhibiting good dispersion in the elastomeric matrix while maintaining the fatigue resistance properties of the elastomeric composition containing it. Thus, one object of the present invention relates to a method for continuously obtaining a coagulum based on at least one elastomer and a reinforcing filler, said method comprising the following steps: a) continuously supplying a first flow of a fluid consisting of an elastomer latex, b) continuously supplying a second flow of a fluid consisting of an aqueous dispersion of a reinforcing filler comprising at least one pyrolysis carbon black, c) bringing said first flow into contact with said second flow in a mixing zone of a coagulation reactor, the continuous contact inducing the formation of a coagulum of the elastomer latex with the aqueous dispersion of the reinforcing filler, d) continuously recovering said coagulum obtained in the previous step. DETAILED DESCRIPTION OF THE INVENTION As explained previously, an object of the present invention relates to a method for continuously obtaining a coagulum based on at least one elastomer and a reinforcing filler, said method comprising the following steps: a) continuously supplying a first stream of a fluid consisting of an elastomer latex, b) continuously supplying a second stream of a fluid consisting of an aqueous dispersion of a reinforcing filler comprising at least one pyrolysis carbon black, c) bringing said first stream into contact with said second stream in a mixing zone of a coagulation reactor, the continuous contact inducing the formation of a coagulum of the elastomer latex with the aqueous dispersion of the reinforcing filler, d) continuously recovering said coagulum obtained in the previous step. The term "coagulum" means the product of the coagulation of one or more elastomers in latex form and one or more reinforcing fillers in particulate form in a liquid, preferably an aqueous liquid, the elastomer(s) and the reinforcing filler(s) coming together to form a single mass. The coagulum production process according to the invention is a continuous process. A "continuous process" is defined as a process in which the feeding of raw materials, the transformation of raw materials, and the production of the final product (here, the coagulum) occur without interruption between the different stages. A continuous process differs from a discontinuous process (or batch process) in which the raw materials are fed at a specific time and for a defined period, then the feeding is stopped, and the transformation stage begins and is stopped when the transformation of the raw materials has reached the desired stage. The product is then extracted, and a new cycle (new batch) starts in the same equipment. The expression "composition based on" means a composition comprising the mixture and / or the in situ reaction product of the different constituents used, some of these constituents being able to react and / or being intended to react with each other, at least partially, during the different phases of manufacturing the composition; the composition can thus be in a totally or partially crosslinked state or in a non-crosslinked state. The expression "part by weight per hundred parts by weight of elastomer" (or pce) means the part, by mass per hundred parts by mass of elastomer or rubber, the two terms being synonymous. In this document, unless expressly stated otherwise, all percentages (%) shown are percentages (%) by mass. On the other hand, any interval of values ​​designated by the expression "between a and b" represents the domain of values ​​going from more than a to less than b (that is, bounds a and b excluded) while any interval of values ​​designated by the expression "from a to b" means the domain of values ​​going from a to b (that is, including the strict bounds a and b). The compounds mentioned in the description can be of fossil origin, derived from biomass. Obviously, the compounds mentioned can also come from the recycling of previously used materials; that is, they can be partially or totally derived from a recycling process, or even obtained from raw materials themselves derived from a recycling process. This includes, in particular, polymers, plasticizers, etc. By "elastomeric matrix" or "elastomeric matrix", we mean the entire set of elastomer(s) present in the elastomeric composition.For the purposes of this invention, "majority" or "majority" means that the compound is the major component among the compounds of the same type in the composition; that is, it is the one that represents the largest quantity by mass among the compounds of the same type. In other words, the mass of this compound represents more than 50% of the total mass of the compounds of the same type in the composition, for example, at least 51%. By way of example, in a system comprising a single elastomer, this compound is the major component within the meaning of this invention; and in a system comprising two elastomers, the major elastomer represents more than half of the total mass of the elastomers; in other words, the mass of this elastomer represents more than 50%, for example, at least 51%, of the total mass of the elastomers. Similarly, a so-called major component is the one representing the largest mass among the components in the composition.In other words, the mass of this filler represents more than 50%, for example at least 51%, of the total mass of fillers in the composition. All glass transition temperature values ​​“Tg” are measured in a known manner by Differential Scanning Calorimetry (DSC) according to ASTM D3418 (2008). The expression "consists essentially of" followed by one or more characteristics means that components or steps which do not significantly modify the properties and characteristics of the invention may be included in the process or material of the invention, in addition to the components or steps explicitly listed. By "dry" we mean a product whose moisture content does not exceed 1% by weight of the total weight of the product. The moisture content is measured by any technique known to a person skilled in the art. By "dry coagulum" is meant a coagulum whose moisture content does not exceed 1% by weight of the total weight of the coagulum. The moisture content is measured by any technique known to a person skilled in the art. A "masterbatch" is a composite based on an elastomer to which a filler, often a reinforcing filler, has been added. In other words, a masterbatch is a premix of a filler, often a reinforcing one, and at least one elastomer. Elastomer The elastomer(s) usable in the context of the process of the invention may preferably be one or more diene elastomers. In common practice, the terms "elastomer" and "rubber" are used interchangeably in the text. The term "diene" elastomer (or, indiscriminately, "rubber"), whether natural or synthetic, is understood to mean, in a known manner, an elastomer composed at least in part (i.e., a homopolymer or a copolymer) of diene monomer units (monomers bearing two carbon-carbon double bonds, conjugated or not). In this application, diene elastomers are by definition non-thermoplastic. These diene elastomers can be classified into two categories: "essentially unsaturated" or "essentially saturated". Generally, "essentially unsaturated" refers to a diene elastomer derived at least in part from conjugated diene monomers, having a proportion of diene motifs or units (conjugated dienes) greater than 15% (mole percent); thus, diene elastomers such as butyl rubbers or EPDM-type diene-alpha-olefin copolymers do not fall under the previous definition and can be described as "essentially saturated" diene elastomers (low or very low proportion of diene motifs, always less than 15%). The term diene elastomer specifically refers to a type of elastomer suitable for use in compositions according to the invention: • any homopolymer of a diene monomer, conjugated or not, having from 4 to 18 carbon atoms; • any copolymer of a diene, conjugated or not, having from 4 to 18 carbon atoms and at least one other monomer. The other monomer can be ethylene, an olefin or a diene, conjugated or not. Suitable conjugated dienes are those with 4 to 12 carbon atoms, in particular 1,3-dienes, such as 1,3-butadiene and isoprene. Suitable as unconjugated dienes are unconjugated dienes having 6 to 12 carbon atoms, such as 1,4-hexadiene, ethylidene norbornene, dicyclopentadiene. Suitable olefins include vinylaromatic compounds with 8 to 20 carbon atoms and aliphatic α-monoolephs with 3 to 12 carbon atoms. Examples of suitable vinylaromatic compounds include styrene, ortho-, meta-, para-methylstyrene, the commercial mixture "vinyl-toluene", and para-tert-butylstyrene. As suitable aliphatic a-monoolefins, acylic aliphatic a-monoolefins having 3 to 18 carbon atoms are particularly suitable. More specifically, diene elastomer can be: • any homopolymer of a conjugated diene monomer, in particular any homopolymer obtained by polymerization of a conjugated diene monomer having 4 to 12 carbon atoms; • any copolymer obtained by copolymerization of one or more dienes conjugated together or with one or more vinylaromatic compounds having 8 to 20 carbon atoms; • any copolymer obtained by copolymerization of one or more dienes, conjugated or not, with ethylene, an α-monoolefin or their mixture such as for example elastomers obtained from ethylene, propylene. In summary, the diene elastomer(s) usable within the scope of the present invention may preferably be chosen from the group of diene elastomers consisting of natural rubber, polybutadienes (abbreviated "BR"), synthetic polyisoprenes ("IR"), butadiene copolymers, isoprene copolymers, and mixtures of these elastomers. Such copolymers are more preferably chosen from the group consisting of butadiene-styrene copolymers (SBR), isoprene-butadiene copolymers (BIR), isoprene-styrene copolymers (SIR), and isoprene-butadiene-styrene copolymers (SBIR). Preferably, the diene elastomer(s) usable within the scope of the present invention may be natural rubber. For the production of a coagulum according to the invention, an elastomeric latex can be used, elastomeric latex being a particular form of elastomer that exists as elastomeric particles dispersed in water. The invention preferably relates to diene elastomeric latexes, diene elastomers being those defined above, including preferred forms; in particular, a natural rubber latex may preferably be used. More specifically, for natural rubber (NR) which can compose all or part of the elastomer according to the invention, this natural rubber exists in different forms as detailed in chapter 3 "Latex concentrates: properties and composition", by KF Gaseley, ADT Gordon and TD Pendle in "Natural Rubber Science and Technology", AD Roberts, Oxford University Press - 1988. In particular, several forms of natural rubber latex are marketed: field latex, concentrated natural rubber latex, epoxy latex, deproteinized latex, and pre-laccanized latex. Field natural rubber latex is a latex to which ammonia has been added to prevent premature coagulation, and concentrated natural rubber latex corresponds to a field latex that has undergone a treatment corresponding to a washing followed by a new concentration. The different categories of concentrated natural rubber latex are listed, in particular, according to ASTM D 1076-06. Among concentrated natural rubber latexes, a distinction is made between concentrated natural rubber latexes of so-called "HA" ("high ammonia") quality and those of so-called "LA" ("low ammonia") quality; for the purposes of this invention, concentrated natural rubber latexes of HA quality will be advantageously used. Natural rubber latex may be pre-modified physically or chemically (centrifugation, enzymatic treatment, chemical modification, etc.). The latex may be used directly or pre-diluted in water to facilitate its application. Preferably, elastomeric latex, particularly diene elastomeric latex, and especially natural rubber latex, may contain one or more antioxidants as described below. It should be noted that it is possible to consider using one or more natural rubber latexes in blending, or a blend of one or more natural rubber latexes with one or more synthetic rubber latexes. As a synthetic elastomeric latex, the latex may in particular consist of a synthetic diene elastomer already available in emulsion form (for example a butadiene and styrene copolymer, SBR, prepared in emulsion), or of a synthetic diene elastomer initially in solution (for example an SBR prepared in solution) which is emulsified in a mixture of organic solvent and water, generally by means of a surfactant. A SBR latex, particularly an emulsion-prepared SBR (“ESBR”) or a solution-prepared SBR (“SSBR”), and more particularly an emulsion-prepared SBR, is particularly suitable for the invention. There are two main types of emulsion copolymerization processes for styrene and butadiene: one, the hot process (carried out at a temperature close to 50°C), is suitable for preparing highly branched SBRs, while the other, the cold process (carried out at a temperature ranging from 15°C to 40°C), produces more linear SBRs. For a detailed description of the effectiveness of several emulsifiers usable in the said hot process (depending on the rates of said emulsifiers), one may, for example, refer to the two articles by CW Carr, M. Kolthoff, EJ Meehan, University of Minnesota, Minneapolis, Minnesota, which appeared in the Journal of Polymer Science in 1950, Vol. V, No. 2, pp. 201-206, and in 1951, Vol. VI, No. 1, pp. 73-81.Regarding comparative examples of implementation of said cold process, one may refer for example to the article U Industrial and Engineering Chemistry, 1948, Vol. 5 40, No. 5, pp. 932-937, EJ Vandenberg, GE Hulse, Hercules Powder Company, Wilmington, Delaware + and to the article U Industrial and Engineering Chemistry, 1954, Vol. 46, No. 5, pp. 1065-1073, JR Miller, HE Diem, BF Goodrich Chemical Co., Akron, Ohio. In the case of an SBR elastomer (ESBR or SSBR), an SBR with a medium styrene content, for example between 20% and 35% by weight relative to the total weight of the copolymer, or a high styrene content, for example 35% to 45% by weight relative to the total weight of the copolymer, is used, along with a molar content of vinyl bonds in the portion butadiene content between 15% and 70%, a trans-1,4 linkage content (mol%) between 15% and 75% and a Tg between -10°C and -55°C; such an SBR can be advantageously used in a mixture with a BR preferably having more than 90% (mol%) of cis-1,4 linkages. According to a preferred embodiment of the invention, a natural rubber latex, in particular a concentrated natural rubber latex, specifically a concentrated natural rubber latex of so-called "HA" quality and / or "LA" quality, will be used. More particularly, concentrated natural rubber latex of so-called "HA" quality. According to another preferred embodiment of the invention, a natural rubber latex from the field will be used. Reinforcing load The reinforcing filler used in the context of the present invention comprises at least one pyrolysis carbon black. The term "reinforcing filler" refers to any type of filler known for its ability to reinforce an elastomeric composition usable in particular for the manufacture of tires, such as virgin carbon black, pyrolysis carbon black, carbon nanotubes, siliceous or aluminous mineral fillers, etc. Pyrolysis carbon black For the purposes of this invention, "pyrolysis carbon black" means carbon black obtained by pyrolyzing a material comprising at least one carbon polymer and carbon black, hereinafter referred to as the material to be pyrolyzed, for example, in the context of recycling such a material. The physical state of the material to be pyrolyzed is irrelevant, whether it is in the form of a dry powder, granules, strip, or any other form, in a crosslinked or non-crosslinked state. Preferably, the material to be pyrolyzed can be recovered from manufactured articles or products generated during their manufacture / production (such as by-products or scrap); these manufactured articles can be selected from the group consisting of pneumatic tires, non-pneumatic tires, industrial conveyor belts, transmission belts, rubber seals, rubber hoses, shoe soles, and windshield wipers. More preferably still, the pyrolysis carbon black usable within the scope of the present invention is a carbon black obtained from a pyrolysis process in which the material to be pyrolyzed is derived from manufactured articles selected from the group consisting of pneumatic and non-pneumatic tires. Pyrolysis, in the context of the present invention, means any type of thermal decomposition in the absence of oxygen, where the raw material is the material to be pyrolyzed as defined above. Pyrolysis carbon blacks are therefore distinguished from virgin carbon blacks, also known as industrial and / or ASTM grade carbon blacks, in that the carbonaceous raw material used for the pyrolysis is a material comprising at least one carbon polymer and carbon black and not materials derived from petroleum cuts or from coal or from oils of natural origin or oils from recycling processes (such as pyrolysis oil). The pyrolysis carbon blacks usable within the framework of the present invention are distinguished from known carbon blacks such as industrial carbon blacks, in particular so-called "furnace" carbon blacks, notably by a higher ash content. Preferably, the pyrolysis carbon black usable within the framework of the present invention has an ash content in the range of 5% to 30% by weight, more preferably in the range of 8% to 25% by weight, more preferably in the range of 10% to 22% by weight, relative to the total weight of the pyrolysis carbon black. Preferably, the pyrolysis carbon black usable within the framework of the present invention has a sulfur content greater than 2% by weight, preferably in the range of 2.5% to 5% by weight, relative to the total weight of the pyrolysis carbon black. Preferably, the pyrolysis carbon black usable within the framework of the present invention has a zinc content greater than or equal to 2% by weight, preferably in a range of 2.5% to 8% by weight, relative to the total weight of the pyrolysis carbon black. Preferably, the pyrolysis carbon black usable within the scope of the present invention has a specific surface area STS A measured according to ASTM D 6556-2021 within a range of 20 to 200 m 2 / g, more preferentially ranging from 30 to 90 m 2 / g. Preferably, the pyrolysis carbon black usable within the framework of the present invention has a void volume measured according to ASTM D7854-21 and at a pressure of 50 MPa within a range of 30 to 60 ml / 100g, more preferably within a range of 35 to 55 ml / 100g. The ash content is determined by calcination in platinum capsules in a muffle furnace at 825°C according to the following protocol. One capsule is pre-identified before each series of measurements and tared to the nearest 0.1 mg; its mass is noted as PO. Five grams of pyrolysis carbon black sample are introduced into the capsule and weighed precisely to the nearest 0.1 mg; this mass is noted as PL. The capsule and its contents are pre-calcined using a Bunsen burner until fumes appear and the product ignites. Once the product has completely burned, the capsule and its contents are placed in a muffle furnace heated to 825°C for 1 hour. After 1 hour, the capsule is removed from the furnace and immediately placed in a desiccator at room temperature. When the capsule and the ash have returned to room temperature, the capsule is weighed again to obtain mass P2.Finally, it is possible to obtain the ash content (% ash) using the formula below: [Math 1] % ash 100 The zinc content in pyrolysis carbon black is determined after calcination of the sample, followed by resuspension of the ash in an acidic medium and analysis by ICP-AES (inductively coupled plasma atomic emission spectroscopy). The ash is obtained using the protocol described above. Approximately 100 mg of ash (test sample) is taken and placed in a PF A (perfluoroalkoxy) tube for use with a HotBlock hot plate. Then, 8 mL of 37% concentrated hydrochloric acid, 3 mL of 65% concentrated nitric acid, and 0.5 mL of 40% hydrofluoric acid are added. The tube is then capped and heated at 130°C for 2 hours. After cooling, the contents are then transferred using ultrapure water into a 100 mL PTFE (polytetrafluoroethylene) volumetric flask already containing 2 g of boric acid (to neutralize the hydrofluoric acid). Ultrapure water is then added to the calibration mark.The resulting solution is diluted 100-fold by taking 1 mL from a 100 mL PTFE flask previously containing 8 mL of 37% concentrated hydrochloric acid, 3 mL of 65% concentrated nitric acid, 0.5 mL of 40% hydrofluoric acid, and 2 g of boric acid. This diluted solution is then filtered through a 0.45 µm GHP syringe filter before being analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES). Prior to the analysis of the diluted solution, at least five standards are analyzed by ICP-AES at zinc concentrations of 0, 0.5, 1, 2, and 5 mg / L. These standards were prepared in 100 mL volumetric flasks by diluting a commercially available solution certified to a zinc concentration of 1 g / L. These volumetric flasks initially contain 8 mL of 37% concentrated hydrochloric acid, 3 mL of 65% concentrated nitric acid, 0.5 mL of 40% hydrofluoric acid, and 2 g of boric acid. The standard solutions are analyzed by ICP-AES at a wavelength of 202.613 nm. For each standard concentration (c), the zinc signal intensity IZn is plotted on a graph IZn = f(c), which corresponds to the calibration curve (of the type y = ax + b). The sample solution (diluted solution) of unknown concentration is then measured under the same conditions as the standards. The measured intensity is related to the concentration using the calibration curve obtained previously. The ash concentration (c) as a mass percentage is thus obtained directly from the software, since the sample size and volume have been previously recorded. The concentration of zinc in pyrolysis black [c]black in mass % is obtained by the following equation: [Math 2] [c black = McAndres * 100 * % Ash The determination of sulfur content in pyrolysis carbon black is carried out using a LECO furnace. LECO sulfur analyzers are designed to measure, in particular, the sulfur content in organic and / or inorganic materials by combustion and non-dispersive infrared detection. Before measuring the sulfur content of the sample, the pods are cleaned and the furnace is calibrated. The LECO furnace pods are cleaned beforehand: the empty pod is analyzed under the same conditions as the samples. The calibration curve is prepared using a commercial standard called "BBOT" with a purity greater than 99.99% and a carbon (C) content of [missing information]. The concentration of hydrogen (H), nitrogen (N), oxygen (O), and sulfur (S) is guaranteed. The specific concentrations are as follows: C%: 72.52%; H%: 6.09%; N%: 6.51%; O%: 7.43%; and S%: 7.44%. Approximately 10 ± 3, 20 ± 3, and 40 ± 3 mg of BBOT are weighed into a capsule. The standard / capsule assembly is introduced into the combustion furnace, which is regulated at 1350 °C under pure oxygen. The combination of the furnace temperature and the analysis flow rate causes the sample to combust and releases sulfur and / or carbon as SCl (g). After 20 seconds, oxygen is introduced through the lance to accelerate the combustion of materials that are difficult to burn. Sulfur and / or carbon, in the form of S₂(g), are carried by an oxygen flow through the infrared detection cells. The instrument's software plots a straight line connecting the introduced standard mass and the observed response (area) on the detector. This yields a calibration line.After thoroughly cleaning the sampling equipment, approximately 80 ± 5 mg of pyrolysis carbon black is weighed and placed in a LECO furnace capsule. The area of ​​the observed SO2 peak is related to the concentration using the calibration curve. The instrument's software then calculates the mass percentage of sulfur in the sample based on the sample mass in the capsule. Pyrolysis carbon blacks are marketed, for example, by Scandinavian Enviro Systems under the reference "P550 HD" or by Bolder Industries under the reference BolderBlack Virgin carbon black The reinforcing charge usable within the scope of the present invention may further comprise at least one carbon black other than pyrolysis carbon black, this carbon black being called "virgin carbon black" because it is not produced from materials already containing carbon black. Virgin carbon black is produced from materials derived from petroleum fractions or coal, or from oils of natural origin or oils obtained from recycling processes (such as pyrolysis oil). As virgin carbon blacks, all carbon blacks are suitable, including carbon blacks conventionally used in tires or their treads, especially industrial carbon blacks, more specifically so-called "furnace" carbon blacks. Among virgin carbon blacks, special mention should be made of reinforcing virgin carbon blacks of the 100, 200, 300 series, or blacks of the 500, 600 or 700 series (ASTM grades D-1765-23b published on December 15, 2023), such as NI 15, NI 34, N234, N326, N330, N339, N347, N375, N550, N683, N772. Virgin carbon blacks can be used in their isolated state, as commercially available, or in any other form, for example as a carrier for certain rubberizing additives used. Virgin carbon blacks could, for example, already be incorporated into diene elastomers, particularly isoprene elastomers, in the form of a masterbatch (see, for example, applications WO97 / 36724-A2 or W099 / 16600-A1). Mineral fillers of the siliceous or aluminous type The reinforcing filler usable within the framework of the present invention may also include at least one inorganic reinforcing filler. Suitable inorganic reinforcing fillers include mineral fillers of the siliceous type, preferably silica (SiCh), or of the aluminous type, in particular alumina (Al2O3).The silica used can be any reinforcing silica known to those skilled in the art, including any precipitated or pyrogenated silica. Precipitated silica can be produced from non-renewable raw materials, including those derived from inorganic sand (silicon dioxide from inorganic sand), recycled materials such as foundry sands, end-of-life tires and in particular the treads of end-of-life tires consisting mainly of silica as a reinforcing filler, or from bio-based raw materials such as organic waste from plants, preferably inedible organic waste from plants. Non-renewable raw materials are defined as raw materials that do not regenerate on a human timescale. These are therefore exhaustible resources. Examples include minerals such as stones or sand, metals, gas, and oil. Among the plants that contain silicon dioxide in their tissues are mustard, grasses, corn, sugarcane bagasse, rice, wheat, and in particular mustard husks, bamboo leaves, corn ears, rice husks, and wheat husks. Silica derived from non-renewable raw materials such as natural inorganic sand is usually obtained by heating sand in a glass furnace in the presence of sodium carbonate. The resulting sodium silicate is then dissolved in water, possibly in the presence of a base such as sodium hydroxide. Precipitated synthetic silica is formed from this aqueous solution by controlled treatment of the silicate with an acid (e.g., a mineral acid and / or an acidifying gas such as carbon dioxide). Sometimes, an electrolyte (e.g., sodium sulfate) may be present to promote the formation of precipitated silica particles. The recovered precipitated silica is amorphous. Silica derived from bio-based raw materials such as those mentioned above can, for example, be obtained by burning the bio-based raw material in order to recover the ash of this bio-based material which contains mainly silicon dioxide.For example, for rice husks, and in a process equivalent to that described above for silicas based on non-renewable or recycled mineral raw materials, rice husk ash is generally treated with a strong base such as, for example, sodium hydroxide, to form an aqueous silicate solution (e.g., sodium silicate). Following this, precipitated synthetic silica is formed by the controlled addition of an acid (e.g., a mineral acid and / or an acidifying gas such as, for example, carbon dioxide) in which an electrolyte (e.g., sodium sulfate) may be present to promote the formation of precipitated silica particles derived from rice husks. The recovered precipitated silica is amorphous precipitated silica. Silica derived from rice husk ash is known to be produced in a way that... Rice husks are called RHA silica (Rice Huks Ash Silica). Bio-based silicas are available, for example, from suppliers such as Solvay, Evonik, Quechen, Wilmar International, Wuxi... In summary, the synthesis of a precipitated silica usable within the framework of the invention can be carried out from a sodium silicate entirely obtained from bio-based, recycled or non-renewable raw materials, but also from a mixture of bio-based and / or recycled and / or non-renewable raw materials. Preferably, precipitated silica, whether obtained from mineral, non-renewable, recycled or bio-based raw materials, has a specific surface area and a CTAB specific surface area both below 450 m² 2 / g, preferably within a range of 30 to 400 m 2 / g, particularly from 60 to 300 m 2 / g. Any type of precipitated silica can be used, including highly dispersible precipitated silicas (known as "HDS" for "highly dispersible" or "highly dispersible silica"). These precipitated silicas, whether highly dispersible or not, are well known to those skilled in the art. Examples include the silicas described in applications W003 / 016215-A1 and W003 / 016387-A1. Among the commercial HDS silicas, the following can be used: “Ulsil ® 5000GR”, “Ulsil ® 7000GR” from Evonik, “Zeosil ® 1085GR”, “Zeosil® 1115 MP”, “Zeosil® 1165MP”, “Zeosil® Premium 200MP”, “Zeosil® HRS 1200 MP” from Solvay. As non-HDS silica, the following commercial silicas may be used: “Ultrasil® VN2GR”, “Ultrasil® VN3GR” silicas from Evonik, “Zeosil® 175GR” silica from Solvay, “Hi-Sil EZ120G(-D)”, “Hi-Sil EZ160G(-D)”, “Hi-Sil EZ200G(-D)”, “Hi-Sil 243LD”, “Hi-Sil 210”, “Hi-Sil HDP 320G” silicas from PPG, “K160”, “K185”, “K195” silicas from Wilmar International. Other examples of inorganic fillers that may be used in compositions include mineral fillers of the aluminous type, in particular alumina (Al2O3), aluminum oxides, aluminum hydroxides, aluminosilicates, titanium oxides, silicon carbides or nitrides, all of the reinforcing type as described for example in applications WO 99 / 28376-A2, WO 00 / 73372-Al, WO 02 / 053634-Al, WO 2004 / 003067-Al, WO 2004 / 056915-A2, US 6 610 261-B1 and US 6 747 087-B2. Examples include the aluminas “Baikalox A125” or “CR125” (Baïkowski company), “APA-lOORDX” (Condéa), “Aluminoxid C” (Evonik) or “AKP-G015” (Sumitomo Chemicals). The physical state of the reinforcing inorganic filler is irrelevant, whether it be in the form of dry powder, microbeads, granules, spheres, or any other suitable densified form. Of course, the term "reinforcing inorganic filler" also refers to mixtures of different reinforcing inorganic fillers, particularly silicas as described above. Those skilled in the art will understand that, in place of the inorganic reinforcing filler described above, a reinforcing filler of another nature could be used, provided that this reinforcing filler of another nature is covered with an inorganic layer such as silica, or has functional sites on its surface, in particular hydroxyl sites, requiring the use of a coupling agent to establish the bond between this reinforcing filler and the diene elastomer. Preferably, pyrolysis carbon black represents more than 50% by weight, more preferably more than 70% by weight, more preferably still more than 90% by weight of the total weight of the reinforcing charge. According to one embodiment of the invention, the reinforcing filler consists essentially of pyrolysis carbon black. In this embodiment, pyrolysis carbon black or a mixture of pyrolysis carbon black constitutes the sole reinforcing filler; another reinforcing filler, different from pyrolysis carbon black, may optionally be present but with trace impurities. In another embodiment of the invention, the reinforcing filler comprises at least one pyrolysis carbon black and at least one second reinforcing filler other than pyrolysis carbon black. This second reinforcing filler may be selected from the group consisting of virgin carbon blacks, silicas, particularly precipitated silicas, and mixtures of these reinforcing fillers. The virgin carbon blacks and silicas usable in this embodiment of the invention are those described above.Thus, according to one embodiment of the invention, the reinforcing filler may comprise a mixture of at least one pyrolysis carbon black and at least one virgin carbon black, or a mixture of at least one pyrolysis carbon black and at least one silica, in particular at least one precipitated silica, or even a mixture of at least one pyrolysis carbon black, at least one virgin carbon black, and at least one silica, in particular at least one precipitated silica. Preferably, in these embodiments of the invention, pyrolysis carbon black constitutes the major component of this type of mixture. Preferably, in this embodiment, pyrolysis carbon black represents more than 50% by weight, more preferably more than 70% by weight, and more preferably more than 90% by weight of the total weight of the reinforcing filler. The total content of the reinforcing filler in the coagulum typically varies from 30 to 90 parts per cubic centimeter, more preferably from 40 to 80 parts per cubic centimeter, and even more preferably from 45 to 70 parts per cubic centimeter. This content is measured by any technique known to those skilled in the art, such as thermogravimetric analysis (TGA). Process The process for continuously obtaining a coagulum based on at least one elastomer and a reinforcing filler comprising at least one pyrolysis carbon black includes at least one step (a) which is the continuous supply of a first stream of a fluid consisting of an elastomeric latex, in particular a diene elastomeric latex, more especially a natural rubber latex. This continuous supply of this first fluid may be carried out using of one or more peristaltic pumps from a reservoir containing the elastomer latex(s). This type of device is described in particular in document US6048923, column 10, lines 50 to column 11, line 14. The reinforcing filler(s) comprising at least one pyrolysis carbon black are used in step b) of the process of the present invention in the form of a fluid consisting of an aqueous dispersion of said filler (also called "slurry" in English). Pyrolysis carbon black and other reinforcing fillers, when present, usable within the scope of the invention are commercially generally in dry form, i.e. in the form of dry powder, microbeads, granules, pellets, beads or any other suitable densified form. Dry pyrolysis carbon black is contacted with water, and the mixture is then passed, for example, through a colloidal mill to form an aqueous dispersion of reinforcing filler. This aqueous dispersion of pyrolysis carbon black can then be passed through a homogenizer, which further disperses the pyrolysis carbon black in water to form the second fluid ("slurry") used in the present invention. Devices for obtaining and continuously supplying the second stream in step b) of the process for continuously obtaining a coagulum according to the invention are described in particular in US patent 6048923, columns 14, lines 35 to 15, lines 40, and in WO2019 / 129999A1, paragraph

[0013] has

[0019] , In step c) of the process, the first stream is brought into contact with the second stream in a mixing zone of a coagulation reactor. The continuous contact of these streams induces the formation of a coagulum of the elastomeric latex with the aqueous dispersion of the reinforcing filler. Preferably, the contact in step c) can be carried out with the following steps: i. feeding the continuous stream of the first elastomeric latex fluid to a mixing zone of a coagulation reactor, defining an elongated coagulation zone extending between the mixing zone and an outlet; ii. feeding the continuous stream of the second fluid of the pressurized aqueous dispersion into the mixing zone of a coagulation reactor to form the coagulum. Even more preferably, the continuous flow of the second fluid is supplied at a higher rate than the continuous flow of the first fluid. This velocity differential can, in particular, allow for rapid coagulation, notably without a coagulation agent, of the elastomer latex with the aqueous reinforcing filler dispersion comprising at least one pyrolysis carbon black. The coagulation reactor comprises an inlet for the various streams, a mixing zone, and an outlet. The coagulation zone in the coagulation reactor extends from the mixing zone, preferably increasing gradually in cross-section in the downstream direction from an inlet end to an outlet end. Examples of reactors include Coagulations and their conditions of use are described in US documents 6048923, 6929783, and 9156955, particularly US document 6048923, columns 14 to 20. They may be used for the implementation of the present invention. The aqueous dispersion of the reinforcing filler comprising at least one pyrolysis carbon black ("pyrolysis carbon black slurry") is introduced into the mixing zone preferably as a continuous, high-speed injected stream, while the elastomeric latex fluid stream, particularly diene elastomer, especially natural rubber latex, is introduced at a relatively low speed.The high velocity, flow rate, and particle concentration of the fluid, consisting of an aqueous dispersion of reinforcing filler comprising pyrolysis carbon black, are sufficient to induce high mixing and shear of the latex fluid, flow turbulence of the mixture in at least a portion upstream of the coagulation zone, and substantially complete coagulation with said latex before the outlet end of the coagulation reactor. Substantially complete coagulation can thus be achieved, according to preferred embodiments, without the need for an acidic or saline coagulation agent.The continuous and simultaneous feeding of the latex fluid stream and the fluid stream of the reinforcing filler suspension comprising at least one pyrolysis carbon black into the mixing zone of the coagulum reactor establishes a continuous flow of a coagulum (in the form of a sausage or "worm" in English) of said latex and of said filler suspension into the coagulum zone. The coagulum is continuously discharged from the outlet of the coagulation reactor in a worm-like fashion. This discharge is a virtually constant and continuous flow, occurring simultaneously with the continuous feeding of the aqueous latex fluid and dispersion fluid, containing at least one pyrolysis carbon black, into the mixing zone of the coagulum reactor. In particular, the worm-like flow and the atmospheric or near-atmospheric pressure conditions at the outlet of the coagulation reactor are highly advantageous for facilitating the control and collection of the coagulum, for example, for subsequent processing, use, and / or drying steps.The feed rates of the elastomeric latex fluid, particularly diene elastomeric latex, preferably natural rubber latex, and of the aqueous reinforcing filler dispersion, including at least pyrolysis carbon black, to the mixing zone of the coagulum reactor can be accurately measured to achieve high yields, with little free latex and little undispersed pyrolysis carbon black in the coagulum exiting the coagulation reactor. The velocity differential between the first and second fluids is important to achieve sufficient turbulence, i.e., sufficiently energetic shear of the elastomeric latex, preferably diene elastomeric latex, more preferably natural rubber latex, thus promoting complete dispersion of the pyrolysis carbon black particles in the latex fluid and their coagulation.High mixing energies produce a new product (coagulum, (in the form of a sausage or "worm" in English)) with excellent dispersion of pyrolysis carbon black particles. The coagulum in the form of a sausage exiting the mixing zone outlet of the coagulation reactor can be used as such for the manufacture of elastomeric compositions. According to a preferred embodiment of the invention, the process further comprises at least one continuous drying step to obtain a dry coagulum, also called a masterbatch. In this step, the coagulum exiting the mixing zone of the coagulation reactor is continuously fed to one or more drying means such as a centrifuge, a drying extruder, an oven, a dryer, a roller tool, etc., and a combination thereof. After the drying step(s), the dry coagulum or masterbatch has a moisture content of 1% or less by weight relative to the total weight of the coagulum, preferably in the range of 0% to 1% by weight relative to the total weight of the coagulum. Examples of implementing one or more drying steps are shown in US 6048923, column 16, and US 6929783, in particular columns 16 to 20 of that document. Another object of the present invention is a coagulum obtained by the process of the invention, preferably a coagulum obtained by the process of the invention which includes at least one drying step. Preferably, dry coagulum is used for the manufacture of elastomeric compositions, in particular for making a rubber article, preferably semi-finished products for pneumatic or non-pneumatic bandages and / or for making pneumatic or non-pneumatic bandages. Variant with antioxidant The coagulum according to the invention may include at least one antioxidant, which may be any antioxidant known to those skilled in the art to prevent or limit the aging of the coagulum attributable to the action of oxygen. The antioxidant is preferentially chosen from the group consisting of substituted p-phenylenediamines, substituted diphenylamines, substituted triphenylamines, quinoline derivatives, antioxidant phenolic compounds, and mixtures thereof. The antioxidant is even more preferentially chosen from the group consisting of substituted p-phenylenediamines and mixtures thereof. When the antioxidant is a substituted p-phenylenediamine (abbreviated "PPD" or "PPDA"), it is preferentially chosen from the group consisting of Nl,3-dimethylbutyl-N'-phenyl-p-phenylenediamine (better known by the abbreviated term "6-PPD"), N-isopropyl-N'-phenyl-p-phenylenediamine (abbreviated "I-PPD"), phenyl-cyclohexyl-p-phenylenediamine, N,N'-di(l,4-dimethyl-pentyl)-p-phenylenediamine, N,N'-diaryl-p-phenylenediamine ("DTPD"), diaryl-p-phenylenediamine ("DAPD"), 2,4,6-tris-(Nl,4-dimethylpentyl-p-phenylenediamino)-l,3,5-triazine ("TAPDT") and mixtures thereof. When the antioxidant is a quinoline derivative (“TMQ”), it is preferentially chosen from the group consisting of l,2-dihydro-2,2,4-trimethylquinoline, 6-ethoxy-l,2-dihydro-2,2,4-trimethylquinoline and mixtures thereof. Examples of substituted diphenylamines or triphenylamines include those described, for example, in applications WO 2007 / 121936, WO 2008 / 055683 and WO 2009 / 138460. In particular, when the antioxidant is a substituted diphenylamine or triphenylamine, it is preferably chosen from the group consisting of 4,4'-bis(isopropylamino)-triphenylamine, 4,4'-bis(l,3-dimethylbutylamino)-triphenylamine, 4,4'-bis(l,4-dimethylpentylamino)-triphenylamine, 4,4',4"-tris(l,3-dimethylbutylamino)-triphenylamine, 4,4',4"-tris(l,4-dimethylpentylamino)-triphenylamine and mixtures thereof. When the antioxidant is an antioxidant phenolic compound, it is preferentially chosen from the group consisting of 2,2'-methylene bis-4-methyl-6-tert-butylphenol ("BPH"), butyl-hydroxy-toluene ("BHT") and their mixtures. Of course, in this description, the term antioxidant can refer to either a single antioxidant compound or a mixture of several antioxidant compounds. The antioxidant can be added to the tank containing the latex, or to the tank containing the reinforcing filler, or injected as a third continuous flow into the mixing zone of the coagulation reactor, or can be added upstream of the centrifuge, or upstream of the drying means, or as described in documents WO2017103518 Al and WO2017103519 Al. Variant adding a second charge In one embodiment of the process, the aqueous dispersion of the reinforcing filler may include at least one second reinforcing filler other than pyrolysis carbon black; the second reinforcing filler being selected from the group consisting of virgin carbon black, silicas, and mixtures of these reinforcing fillers. When the second filler is virgin carbon black, this virgin carbon black may be contacted with water at the same time as the pyrolysis carbon black is contacted with water. In other words, the pyrolysis carbon black and the virgin carbon black may be contacted with water in a single reservoir, the mixture then passing through the colloid mill to form an aqueous dispersion of reinforcing filler, then to the homogenizer, and finally to the coagulation reactor as described above.In another embodiment of the invention, virgin carbon black can be brought into contact with water in a separate tank from that containing pyrolysis carbon black and water. In this embodiment, two separate streams can be sent to a single colloidal mill to form the aqueous dispersion of reinforcing filler, or each separate stream is sent continuously to a separate colloidal mill and to a separate homogenizer, then each stream feeds the coagulation reactor as described above, i.e., the two streams of aqueous dispersion of fillers are sent under pressure continuously into the mixing zone of the coagulation reactor at a significantly higher speed (at least 10 times). superior) than the flow velocity of the elastomeric latex fluid, in particular diene elastomeric latex, preferably natural rubber latex. In the embodiment where the second filler can be a reinforcing inorganic filler, for example silica, particularly precipitated silica, a coupling agent for the silica to the diene elastomer can also be used. These coupling agents (or bonding agents) are well known and are at least bifunctional compounds designed to ensure sufficient chemical and / or physical connection between the reinforcing inorganic filler and the diene elastomer. Organosilanes or polyorganosiloxanes, at least bifunctional, are used in particular. "Bifunctional" means a compound possessing a first functional group capable of interacting with the reinforcing inorganic filler and a second functional group capable of interacting with the elastomer, particularly the diene.For example, such a bifunctional compound may include a first functional group comprising a silicon atom, said first functional group being able to interact with the hydroxyl groups of a reinforcing inorganic charge and a second functional group comprising a sulfur atom, said second functional group being able to interact with the elastomer, in particular a diene elastomer. Preferably, organosilanes are chosen from the group consisting of polysulfide organosilanes (symmetric or asymmetric) such as bis(3-triethoxysilylpropyl) tetrasulfide, abbreviated TESPT and marketed under the name "Si69" by Evonik, or bis-(triethoxysilylpropyl) disulfide, abbreviated TESPD and marketed under the name "Si75" by Evonik; polyorganosiloxanes; mercaptosilanes; and blocked mercaptosilanes, such as S-(3-(triethoxysilyl)propyl) octanethioate, marketed by Momentive under the name "NXT Silane". More preferably, the organosilane is a polysulfide organosilane. In this embodiment of the invention, the reinforcing inorganic filler is brought into contact with water in a stirred tank.According to a preferred embodiment of this variant, the coupling agent of the reinforcing inorganic filler and the reinforcing inorganic filler are added simultaneously to water, and the mixture is continuously passed through a colloidal mill and then a homogenizer. In another embodiment of this variant, the coupling agent is brought into contact with the aqueous dispersion of the reinforcing inorganic filler upstream of the colloidal mill and upstream of the homogenizer. In yet another embodiment, the coupling agent is brought into contact with the reinforcing inorganic filler downstream of the homogenizer and upstream of the mixing zone of the coagulation reactor. Thus, the coupling agent reacts with the reinforcing inorganic filler before the coagulation phase, and the resulting inorganic reinforcing filler can be described as pre-grafted or hydrophobicated by the coupling agent.In another variant, a commercial hydrophobic inorganic reinforcing charge, such as "Agilon" silicas, can be used. In these different embodiments, the flow of hydrophobic inorganic reinforcing charge is sent under pressure and at high speed to the mixing zone of the coagulation reactor, either simultaneously with the continuous, pressurized flow of the reinforcing charge including pyrolysis black, or with a delay of a few seconds (2 to 10 seconds) relative to the flow of the reinforcing charge fluid including pyrolysis carbon black. Variant adding a second elastomer In a variant of the process of the invention, which can be combined with the various embodiments mentioned above, a second elastomer latex, different from the first latex, in particular a second diene elastomer latex, or more preferably a synthetic elastomer latex, is used. As previously stated, the second latex can be mixed with the first latex in the same reservoir, and this mixture supplies the mixing zone of the coagulation reactor with a first fluid. In one embodiment of the process, the latex of the second elastomer is in a separate reservoir from the reservoir containing the first latex. Another peristaltic pump continuously supplies the mixing zone of the coagulation reactor from this second reservoir.Thus, the mixing zone of the coagulation reactor is continuously fed by the latex fluid of the first elastomer and continuously by the latex fluid of the second elastomer, both fluids having the same velocity, which is lower than the feed velocity of the second flow, which consists of the aqueous dispersion of reinforcing filler comprising pyrolysis carbon black. In another variant of this embodiment, the continuous flow of the second latex elastomer is injected upstream of the outlet of the mixing zone of the coagulation reactor; that is, the second latex is injected into the flow of the coagulum that forms. An example of this embodiment is described in document WO20211034589, more specifically in paragraphs [insert paragraphs here].

[0029] has

[0067] , Elastomeric composition Another object of the present invention is an elastomeric composition comprising at least one coagulum as defined above, in particular a dry coagulum also called a masterbatch and at least one crosslinking system. Thus, preferably the elastomeric composition according to the invention may comprise at least one crosslinking system and at least one master blend based on an elastomer, in particular dienic and preferably natural rubber, and at least one reinforcing filler comprising at least one pyrolysis black, said master blend being obtained by liquid mixing as explained above. The crosslinking system can be any type of crosslinking system known to those skilled in the art in the field of elastomeric compositions. It may, in particular, be based on sulfur, and / or peroxide, and / or bismaleimides. Preferably, the crosslinking system is sulfur-based; this is then referred to as a vulcanization system. The sulfur can be supplied in any form, including molecular sulfur or a sulfur-donating agent. At least one vulcanization accelerator is also preferably present, and optionally, various known vulcanization activators may be used, such as zinc oxide, stearic acid, or equivalent compounds like stearic acid salts and transition metal salts, guanidine derivatives (especially diphenylguanidines), or known vulcanization retarders. Sulfur is used at a preferential rate in the range of 0.5 to 12 parts per thousand (ppm), particularly from 1 to 10 ppm. The vulcanization accelerator is used at a preferential rate of 0.5 to 10 ppm, more preferably from 0.5 to 5.0 ppm. Any compound capable of acting as a vulcanization accelerator for elastomers, particularly diene elastomers, in the presence of sulfur, may be used as an accelerator, including thiazole-type accelerators and their derivatives, sulfenamide-type accelerators, thiuram-type accelerators, dithiocarbamate-type accelerators, dithiophosphate-type accelerators, thiourea-type accelerators, xanthate-type accelerators and mixtures of these accelerators. Examples of such accelerators include the following compounds: 2-mercaptobenzothiazyl disulfide (abbreviated "MBTS"), N-cyclohexyl-2-benzothiazyl sulfenamide ("CBS"), N,N-dicyclohexyl-2-benzothiazyl sulfenamide ("DCBS"), N-ter-butyl-2-benzothiazyl sulfenamide ("TBBS"), N-ter-butyl-2-benzothiazyl sulfenamide ("TBSI"), tetrabenzylthiuram disulfide ("TBZTD"), zinc dibenzyldithiocarbamate ("ZBEC"), and mixtures of these compounds. The elastomeric compositions according to the invention may also include all or part of the usual additives and processing agents known to those skilled in the art and commonly used in elastomeric compositions for pneumatic or non-pneumatic tires, in particular treads, such as plasticizers (such as plasticizing oils and / or plasticizing resins), fillers (reinforcing or non-reinforcing / (the same as those mentioned above or others than those mentioned above), pigments, protective agents such as anti-ozone waxes, chemical anti-ozonants, antioxidants, anti-fatigue agents, reinforcing resins (such as described for example in application WO 02 / 10269). The rubber composition according to the invention can be manufactured in suitable mixers, using two successive preparation phases well known to those skilled in the art: - a first thermomechanical working or mixing phase (the so-called "non-productive" phase), which can be carried out in a single thermomechanical step during which all the necessary constituents are introduced into a suitable mixer such as a standard internal mixer (for example, of the 'Banbury' type), i.e. the master mixture obtained by the process of the invention, any other possible reinforcing or non-reinforcing fillers, any other miscellaneous additives, with the exception of the crosslinking system. The non-productive phase can be carried out at high temperature, up to a maximum temperature within a range of 110°C to 200°C, preferably from 130°C to 185°C, for a duration generally within a range of 2 to 10 minutes. - a second mechanical working phase (the so-called "productive" phase), which is carried out in an external mixer such as a roller mixer, after cooling the mixture obtained during the first non-productive phase to a lower temperature, typically below 120°C, for example ranging from 40°C to 100°C. The crosslinking system, preferably the vulcanizing system, is then incorporated, and the whole is then mixed for a few minutes, for example from 5 to 15 min. The final composition thus obtained can then be calendered, for example in the form of a sheet or plate, particularly for characterization in the laboratory, or extruded in the form of a semi-finished (or profile) elastomeric product usable, for example, as a tread for pneumatic or non-pneumatic tires. The composition can be either in its raw state (before crosslinking or vulcanization), or in its cooked state (after crosslinking or vulcanization), and can be a semi-finished product that can be used in a tire. The crosslinking of the composition can be carried out in a manner known to those skilled in the art, for example at a temperature within a range of 130°C to 200°C, under pressure. 2 Rubber item Another object of the present invention relates to a rubber article comprising at least one coagulum as described above, preferably a dried coagulum or at least an elastomeric composition as defined above. The rubber article can be any type of article such as a hose, pipe, seal, O-ring, transmission belt, engine mount, anti-vibration system, window profile, car body and window sealing profile, electrical cable insulation, shoe sole, rubber mat, conveyor belt, semi-finished article for pneumatic bandages, semi-finished article for non-pneumatic bandages, pneumatic bandage, non-pneumatic bandage. Preferably, the rubber article is chosen from the group consisting of semi-finished articles for pneumatic bandages, semi-finished articles for non-pneumatic bandages, pneumatic bandages and non-pneumatic bandages. More preferably, the coagulum as defined above, more preferably the dry coagulum, or the elastomeric composition as defined above useful within the framework of the invention constitutes all or part of said semi-finished article. More preferably, the coagulum as defined above, more preferably the dry coagulum, or the elastomeric composition as defined above useful within the framework of the invention constitutes all or part of the pneumatic or non-pneumatic bandage. Semi-finished products for pneumatic or non-pneumatic tires are rubber products intended for the manufacture of pneumatic or non-pneumatic tires. These can include any type of rubber strip, such as treads, underlayers, etc., crown reinforcement plies (e.g., working plies, protective plies, or reinforcement plies), carcass reinforcement plies, sidewall plies, bead plies, protector plies, underlayer plies, rubber block plies, and other plies providing the interface between the aforementioned areas of the tire. Preferably, the semi-finished article for pneumatic or non-pneumatic tires can be chosen from the group consisting of treads, underlayers, working layers, protective layers, reinforcing layers, carcass reinforcement layers, sidewall layers, bead layers, protector layers; preferably it can be a tread. As is well known, the tread of a pneumatic or non-pneumatic tire comprises a rolling surface designed to be in contact with the ground when the tire is in motion. The tread has a pattern including tread elements or elementary blocks delimited by various main grooves, longitudinal or circumferential, transverse or oblique; the elementary blocks may also include various finer incisions or sipes. Advantageously, the coagulum(s) as defined above, preferably the dry coagulum(s), or the elastomeric composition as defined above useful within the scope of the invention, may be present in the tread of the pneumatic or non-pneumatic tire, preferably in the radially outer portion of the tread intended to be in contact with the ground when the tire rolls. More preferably still, the coagulum(s) as defined above, preferably the dry coagulum(s), or the elastomeric composition as defined above useful within the scope of the invention, may constitute all or part of the tread, particularly for pneumatic or non-pneumatic tires. A "pneumatic tire" is a tire designed to form a cavity by cooperating with a supporting element, such as a rim. This cavity is capable of being pressurized to a pressure higher than atmospheric pressure. A pneumatic tire includes usually two beads intended to come into contact with a rim, a crown consisting of at least one crown reinforcement and a tread, two sidewalls, the tire being reinforced by a carcass reinforcement anchored in the two beads. In contrast, a "non-pneumatic tire" is a tire that supports a vehicle's load by means other than pressurized inflation gas. Thus, a non-pneumatic tire is a toroidal body made of at least one polymeric material, designed to perform the function of a tire but without being subjected to inflation pressure. A non-pneumatic tire can be solid or hollow. A hollow non-pneumatic tire may contain air, but at atmospheric pressure; that is, it lacks the pneumatic rigidity provided by inflation gas at a pressure higher than atmospheric pressure. A non-pneumatic tire typically consists of a base, designed, for example, for mounting on a rigid rim, a crown reinforcement that connects to a tread, and a deformable structure, such as spokes, ribs, or dimples, positioned between the base and the crown.Such non-pneumatic bandages do not necessarily include a flank. Non-pneumatic bandages are described, for example, in documents WO 03 / 018332 and FR2898077. The pneumatic tires according to the invention can be intended to equip in particular vehicles of all types such as passenger vehicles, two-wheeled vehicles, industrial vehicles chosen from vans, heavy goods vehicles, subways, buses, road transport vehicles (trucks, tractors, trailers), off-road vehicles such as agricultural or civil engineering vehicles, and all other transport or handling vehicles or aircraft or, more generally, on any rolling device. The non-pneumatic tires according to the invention are intended to be fitted preferentially to passenger vehicles or two-wheeled vehicles. EXAMPLES OF THE INVENTION'S IMPLEMENTATION 1 -Measures 1-1- Measurement of the fatigue resistance of an elastomeric composition An elastomeric composition can be characterized with respect to its resistance to cracking by a fatigue test. Fatigue resistance, expressed in number of cycles or in relative unit (percentage of a number of cycles relative to a reference number of cycles), is measured on 12 specimens subjected to repeated tensile stresses at a frequency of 1.75 Hz until an elongation of 75%, at a temperature of 23 °C, using a Monsanto apparatus (type "MFTR") until the specimen breaks, applying the protocol described in ASTM D4482-85 and ISO 6943-2017 to dumbbell-shaped specimens known as B15 (78.5 mm long, 1.5 mm thick, 15 mm wide). With results expressed in relative units, a value higher than that of a reference control, arbitrarily set at 100, indicates an improved result, i.e., better fatigue resistance of the elastomeric blend samples. Conversely, a value lower than 100 indicates a degraded result, i.e., poorer fatigue resistance of the elastomeric blend samples. 1-2 Dispersion In a known manner, the charge dispersion in an elastomeric matrix can be represented by the Z note, which is measured, after crosslinking, according to the method described by S. Otto et al. in Kautschuk Gummi Kunststoffe, 58 Jahrgang, NR 7-8 / 2005, in accordance with ISO 11345. The calculation of the Z score is based on the percentage of surface area in which the charge is not dispersed ("% undispersed surface"), as measured by the "disperGRADER+" device supplied with its operating instructions and "disperDATA" operating software by Dynisco according to the equation: Z = 100 - (% undispersed area) / 0.35 The percentage of undispersed surface area is measured using a camera observing the surface of the sample under incident light at 30°. Light spots are associated with filler and agglomerates, while dark spots are associated with the rubber matrix; digital processing transforms the image into a black and white image, and allows the determination of the percentage of undispersed surface area, as described by S. Otto in the aforementioned document. The higher the Z score, the better the dispersion of the charge in the elastomeric matrix (a Z score of 100 corresponds to perfect dispersion and a Z score of 0 to poor dispersion). 2 - Manufacturing of elastomeric compositions 2.1- Obtaining compositions by bulk mixing: The control compositions T1 and T2 to be tested are prepared as follows: natural rubber in solid form is introduced into an internal mixer, filled to 70% by volume and with an initial tank temperature of approximately 60°C. This is followed by solid virgin carbon black or solid pyrolysis carbon black to obtain a masterbatch (method a). The various other ingredients, with the exception of sulfur and the vulcanization accelerator, are then added to this masterbatch. A thermomechanical process (non-productive phase) is then carried out in one or two stages (total mixing time of approximately 3 to 6 minutes, until a maximum "drop" temperature of approximately 160-165°C is reached). The resulting mixture is collected, cooled, and then sulfur and the accelerator are added. vulcanization on an external mixer (homo-finisher) at 40°C, mixing everything (productive phase) for 4 to 10 minutes. The T1 and T2 compositions are then shaped for measurements of their physical or mechanical properties (for example in the form of test specimens) and if necessary baked (or vulcanized) for measurements of baked properties. 2.2- Obtaining compositions from a master mix obtained by liquid mixing: Compositions T3 and Cl are obtained from a masterbatch obtained by liquid mixing according to the process described in US document 6,929,783 The elastomer used to obtain the T3 and Cl compositions is a natural rubber in the form of latex and more particularly a natural field rubber with a dry mass concentration of 34.2%. Carbon blacks are used in the form of an aqueous dispersion prepared at a mass concentration of 15.5%, whether for virgin carbon black or for pyrolysis carbon black, by mixing solid virgin carbon black or solid pyrolysis carbon black (in dry powder form) in deionized water and stirring. The aqueous dispersion of virgin carbon black for composition T3 or pyrolysis carbon black for composition Cl is sent at a mass flow rate of 175 kg / h through a progressive gravity pump (Noy Mono single-series W range Widethroat pump) to the grinder (IKA DR2000 / 10 grinder) and then to the high-pressure homogenizer (GEA Niro Soavi Ariete NS 3015H) which operates at an inlet pressure of 200 bar. The aqueous dispersion of carbon black exiting the homogenizer is injected into the mixing zone of the coagulation reactor at a mass flow rate of 175 kg / h and coagulates with the rubber latex also fed into this mixing zone at a mass flow rate of 125 kg / h. The coagulation reactor is the one described in columns 14 to 16 of US document 6,929,783 and columns 14 to 21 of US document 6048923. At the exit of the coagulation reactor, a coagulum (also called "worms / crumb" in English) is obtained which is sent to a single screw extruder (also called a drying spinner or "dewatering extruder" in English). At the outlet of the drying centrifuge, the drained coagulum, which has approximately 19% moisture content by weight relative to the total weight of the drained coagulum, is sent to a continuous reactor equipped The reactor consists of two axial rotors (Kobelco KTX-46 twin-screw extruder). The double jacket temperature of this continuous reactor is 140°C, it operates at a speed of 175 rpm, and the output flow rate is 836 g / min. The coagulum is then sent to the roller tool (ME 400 roller tool, Lescuyer) which has a 2.5 mm air gap, a coefficient of friction of 0.9, and operates at a speed of 20 m / min. Upon exiting the roller tool, the coagulum is dry (moisture content less than 1% by weight of the total coagulum weight) and can be used as a masterbatch for the manufacture of T3 and Cl elastomeric compositions The previously obtained masterbatch is introduced into an internal mixer, filled to 70% by volume, with an initial tank temperature of approximately 60°C. The various other ingredients, with the exception of sulfur and the vulcanization accelerator, are then added to this masterbatch. A thermomechanical process (non-productive phase) is then carried out in one or two stages (total mixing time of approximately 3 to 6 minutes, until a maximum "drop" temperature of approximately 160-165°C is reached). The resulting mixture is collected, cooled, and then sulfur and the vulcanization accelerator are added to an external mixer (homo-finisher) at 40°C, where the mixture is blended for 4 to 10 minutes (productive phase). The T3 and Cl compositions are then shaped for measurements of their physical or mechanical properties (for example in the form of test specimens) and if necessary baked (or vulcanized) for measurements of baked properties. 3 Example 1 The purpose of this test is to highlight an improvement in the fatigue resistance properties of an elastomeric composition (composition Cl according to the invention) based on a master mixture comprising at least one pyrolysis carbon black, said master mixture being obtained according to the process of the invention. The formulations of the tested compositions are presented in Table 1. Quantities are expressed in parts per cent (parts by weight per hundred parts by weight of elastomer). [Table 1] Table 1 (1) Virgin carbon black, grade N134 according to ASTM D1765-17 (ash content measured by the method described above: 0.44%; sulfur content measured by the method described above: 0.57%; zinc content: 221 ppm (ppm: parts per million) (percentages are weight percentages relative to the weight of virgin carbon black). This carbon black is produced from non-recycled liquid petroleum-based raw materials and is commercially available from Orion, Cabot, etc. (2) “P550” pyrolysis carbon black from Scandinavian Enviro Systems (ash content measured according to the method described above: 18.5%; sulfur content measured according to the method described above: 3%; zinc content: 4.5% (percentages are weight percentages relative to the weight of the pyrolysis carbon black); STSA specific surface area: 56 m² 2 / g (ASTM D6556-2021); vacuum volume at 50MPa: 44ml / 100g (ASTM D7854-21). This pyrolysis carbon black is produced from end-of-life tires that are pyrolyzed. (3) N-cyclohexyl-2-benzothiazyl-sulfenamide marketed by Flexys under the reference “Santocure CBS” (4) Stearin marketed by the company Uniquema under the name "Pristerene 4931" (5) Industrial grade zinc oxide (6) N-cyclohexyl-2-benzothiazyl-sulfenamide marketed by Flexys under the reference “Santocure CBS” (a) Natural rubber and virgin carbon black or pyrolysis carbon black are mixed by bulk as explained in paragraph 2.1 below (b) Natural rubber and virgin carbon black or pyrolysis carbon black are mixed in liquid form as explained in paragraph 2.2 below The properties of the compositions T1, T2, T3 and Cl measured after cooking at 150°C for 15 min are reported in Table 2. [table 2] Table 2 Replacing virgin carbon black with pyrolysis carbon black leads to a significant decrease in the fatigue strength of the T2 control composition compared to the TL control composition. We also observe a low dispersion of pyrolysis carbon black in the T2 composition. The use of the liquid-based mixing technique (composition T3) instead of bulk mixing (composition Tl) leads to a significant improvement in the fatigue resistance of the control composition T3 compared to the control composition Tl Unexpectedly, the incorporation by liquid mixing of pyrolysis carbon black makes it possible to obtain an elastomeric composition (composition Cl according to the invention) exhibiting good dispersion of pyrolysis carbon black and a significantly improved fatigue resistance property compared to an elastomeric composition in which pyrolysis carbon black is conventionally incorporated by mass mixing (control composition T2).The use of a masterbatch obtained by liquid mixing certainly improves the fatigue resistance of an elastomeric composition with virgin carbon black, as shown by the comparison of compositions T1 / T3. However, when using pyrolysis carbon black (composition Cl), this improvement is significantly greater than the sum of the effects obtained by replacing virgin carbon black with pyrolysis carbon black (comparison T1 / T2) and by replacing bulk mixing with liquid mixing (comparison T1 / T3). The elastomeric composition of invention C2 exhibits good dispersion of the pyrolysis carbon black and maintains its mechanical properties while limiting the environmental impact of its manufacture. 4 Example 2 This test aims to highlight an improvement in the fatigue resistance properties of an elastomeric composition based on 60 parts carbon black in a masterbatch obtained by liquid mixing. The formulations of the tested compositions are presented in Table 3. Quantities are expressed in parts per cent (parts by weight of elastomers). [Table 3] Table 3 Ingredients (1) to (6) are identical to those in Table 1. (a) Natural rubber and ASTM grade virgin carbon black or pyrolysis carbon black are mixed by bulk as explained in paragraph 2.1 above (b) Natural rubber and ASTM grade virgin carbon black or pyrolysis carbon black are mixed in liquid form as explained in paragraph 2.2 above. Compositions T4 and T5 are prepared in the same way as compositions T1 and T2 and according to the process described in 2.1. Compositions T6 and C2 are prepared in the same way as compositions T3 and Cl, according to the process described in 2.2, by adjusting the slurry values ​​of pyrolysis carbon black to obtain the correct concentration of pyrolysis carbon black in the coagulum. The properties of compositions T4, T5, T6, and C2, measured after firing at 150°C for 15 min, are reported in Table 4. [table 4] Table 4 As with example 1, it is unexpectedly observed that with a rate of 60 parts per cent of pyrolysis carbon black, a composition C2 (according to the invention) is obtained which exhibits good dispersion of pyrolysis carbon black and improved fatigue resistance which is greater than the sum of the effects obtained by replacing virgin carbon black with pyrolysis carbon black (comparison T4 / T5) and by replacing bulk mixing with liquid mixing (comparison T4 / T6).

Claims

Demands 1. A process for continuously obtaining a coagulum based on at least one elastomer and a reinforcing filler, said process comprising the following steps: a) continuously supplying a first stream of a fluid consisting of an elastomer latex, b) continuously supplying a second stream of a fluid consisting of an aqueous dispersion of a reinforcing filler comprising at least one pyrolysis carbon black, c) bringing said first stream into contact with said second stream in a mixing zone of a coagulation reactor, the continuous contact inducing the formation of a coagulum of the elastomer latex with the aqueous dispersion of the reinforcing filler, d) continuously recovering said coagulum obtained in the preceding step.

2. A method for continuously obtaining a coagulum according to the preceding claim, wherein the pyrolysis carbon black has an ash content in the range of 5% to 30% by weight, more preferably from 8% to 25% by weight, more preferably from 10% to 22% by weight, relative to the total weight of the pyrolysis carbon black.

3. A method for continuously obtaining a coagulum according to any one of the preceding claims, wherein the pyrolysis carbon black has a sulfur content greater than 2% by weight, preferably in the range of 2.5% to 5% by weight, relative to the total weight of the pyrolysis carbon black.

4. A method for continuously obtaining a coagulum according to any one of the preceding claims, wherein the pyrolysis carbon black has a zinc content greater than or equal to 2% by weight, preferably in the range of 2.5% to 8% by weight, relative to the total weight of the pyrolysis carbon black.

5. A method for continuously obtaining a coagulum according to any one of the preceding claims, wherein the elastomer is a diene elastomer.

6. A method for continuously obtaining a coagulum according to any one of the preceding claims, wherein the elastomer is selected from the group consisting of natural rubber, polybutadienes, synthetic polyisoprenes, butadiene copolymers, isoprene copolymers and mixtures of these elastomers, preferably the elastomer is natural rubber.

7. A method for continuously obtaining a coagulum according to any one of the preceding claims, wherein the aqueous dispersion of reinforcing filler comprises at least a second reinforcing charge different from pyrolysis carbon black; the second reinforcing charge being chosen from the group consisting of virgin carbon blacks, silicas and mixtures of these reinforcing charges.

8. A method for continuously obtaining a coagulum according to any one of the preceding claims, wherein the pyrolysis carbon black represents more than 50% by weight, more preferably more than 70% by weight, more preferably more than 90% by weight of the total weight of the reinforcing filler.

9. A method for continuously obtaining a coagulum according to any one of the preceding claims, wherein the contacting of step c) is carried out with the following steps: i. supplying the continuous flow of the first elastomer latex fluid to a mixing zone of a coagulation reactor defining an elongated coagulation zone extending between the mixing zone and an outlet, ii. supplying the continuous flow of the second fluid of the pressurized aqueous dispersion into the mixing zone of a coagulation reactor to form the coagulum.

10. A method for continuously obtaining a coagulum according to any one of the preceding claims, further comprising at least one continuous drying step to obtain a dry coagulum.

11. Coagulum obtained according to the process as defined in any one of claims 1 to 10, preferably obtained according to the process of claim 10.

12. Elastomeric composition comprising at least one coagulum as defined in claim 11 and at least one crosslinking system.

13. Rubber article comprising at least one coagulum as defined in claim 11 or at least one elastomeric composition as defined in claim 12, preferably the rubber article is a semi-finished product for pneumatic or non-pneumatic bandage or a pneumatic or non-pneumatic bandage.

14. Semi-finished product for pneumatic or non-pneumatic tire according to claim 13, the semi-finished product being selected from the group consisting of treads, underlayers, working plies, protective plies, reinforcing plies, carcass reinforcement plies, sidewall plies, bead plies, protector plies; preferably being a tread.

Citation Information

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