Filler Composition

Abstract

Provided is an acetylene carbon black composition recovered from a vulcanization bladder compound that exhibits excellent vulcanization performance. The present invention relates to a filler composition comprising or consisting of (a) acetylene carbon black, (b) zinc and / or zinc compounds, and optionally (c) ash.

Description

[Technical Field]

[0001] The present invention relates to the field of industrial fillers, particularly fillers for the tire industry, and relates to filler compositions containing acetylene carbon black with improved vulcanization performance, methods for obtaining such compositions, and various related applications. [Background technology]

[0002] In tire technology, crosslinking refers to the process of applying pressure to a green tire in a mold to achieve its final shape and applying heat energy to promote chemical reactions between the rubber compound and other materials. The green tire is automatically transported onto the bead seat of the lower mold. A rubber bladder is inserted into the green tire, and the mold is closed while the bladder inflates. Once the mold is closed and locked, the bladder pressure is increased, causing the green tire to flow into the mold, transferring the tread pattern and sidewall lettering engraved into the mold. The bladder is filled with a circulating heat transfer medium such as steam, hot water, or inert gas. Once crosslinking is complete, the pressure is reduced, the mold is opened, and the tire is removed from the mold.

[0003] A useful ingredient for curing bladder compounds is acetylene carbon black, which, due to its very high degree of graphitization, provides higher thermal conductivity than furnace carbon black at comparable loads. This property accelerates the green tire curing process, shortening curing times, increasing throughput per curing unit, and reducing energy consumption in tire plants.

[0004] Acetylene carbon black is obtained by partially burning acetylene in furnace units operating in parallel. In each furnace, the acetylene carbon black is pyrolyzed at very high temperatures. The combustion gases and acetylene carbon black are then separated, concentrated, and transported to a bag filter system. Compared to furnace black, the standard in the carbon black market, acetylene carbon black is superior in that it is highly pure and contains almost no impurities. These advantages come from the purity of acetylene as a raw material and the extremely high temperature at which it is pyrolyzed.

[0005] While the lifespan of a conventional tire is one to about 10 years, the life cycle of a bladder is much shorter. This short lifespan, combined with the fact that a typical bladder composition contains about 50 phr (30 wt%) of acetylene carbon black, makes vulcanization bladders an interesting source for the recovery of acetylene carbon black.

[0006] The pyrolysis of waste tires and waste tire debris has long been a technical challenge and is, for example, the subject of numerous patent publications.

[0007] Patent document 1 provides a system comprising a pyrolysis chamber having a tire carcass inlet port and communicating with at least a duct for supplying combustion air, the pyrolysis chamber further having a conically-shaped, convex stationary bottom communicating with a steam generator and coaxially communicating with the combustion air duct, and further comprising a rotating arm member associated with the stationary bottom and adapted to discharge waste unburned material from an outlet port formed through the stationary bottom.

[0008] Patent Document 2 discloses an apparatus and method for reprocessing pulverized organic waste, such as rubber waste from worn automobile tires, by pyrolysis, which method includes the steps of pyrolyzing the pulverized waste in either a bed or bath pyrolysis tank having a temperature in the range of 450 to 550°C to form a mixture containing volatile, liquid, and solid components, collecting at least a portion of the volatile components from the gas space above the pyrolysis tank and transferring the collected volatile components from the pyrolysis tank for further utilization, and intermittently or continuously introducing gas into the gas space above the pyrolysis tank.

[0009] Patent Document 3 provides a method and apparatus for producing carbon black, which comprises separating a gasification furnace into a lower gasification section and an upper pyrolysis section via a distribution plate, supplying waste tire chips to the pyrolysis section of the gasification furnace for pyrolysis and separating them into pyrolysis gas and fixed carbon, separating fine fixed carbon from the mixed gas discharged from the gasification furnace and supplying it to the gasification section of the gasification furnace to generate gasification gas, supplying this gasification gas to the pyrolysis section via a distribution plate, separating the fine fixed carbon, and then introducing a mixed gas of the pyrolysis gas and gasification gas to obtain carbon black.

[0010] Patent document 4 relates to a method for recovering a mixture of carbon and hydrocarbons from waste tires or similar polymeric materials by pyrolysis, which method uses a reactor in which the material is placed in a largely fragmented state, and which heats the material to pyrolysis temperatures by recirculation of pre-produced, heated pyrolysis gases that are introduced into the material, and which condense the pyrolysis gases thus obtained into condensable products in a condenser connected to the reactor.

[0011] US Patent No. 5,929,633 claims a process and system for recovering desired constituent materials from vehicle tire debris by pyrolysis. The system comprises a pyrolysis section divided into multiple individual heating zones.

[0012] Patent document 6 relates to the thermal treatment of recycled hydrocarbon feedstock, in particular used tires, which allows for increased processing efficiency and reduced energy costs. The method involves pyrolysis of shredded tires in a reducing gas medium at temperatures between 550 and 800°C and separation of the pyrolysis products.

[0013] For example, Patent Document 7 discloses pelletized acetylene carbon black having a maximum mass strength of 200 N as measured in accordance with ASTM D 1937-10 and an average pellet size of at least 1.0 mm as measured in accordance with ASTM D 1511-10, the use of any of the pelletized acetylene carbon blacks to prepare a compound comprising a resin, polymer, or rubber matrix and the acetylene carbon black dispersed in the matrix, and a method for preparing such a compound. [Prior art documents] [Patent documents]

[0014] [Patent Document 1] European Patent 0287534 B1 [Patent Document 2] European Patent 0592057 B1 [Patent Document 3] European Patent 0768345 B1 [Patent Document 4] European Patent 1114122 B1 [Patent Document 5] European Patent 1163092 B1 [Patent Document 6] European Patent 1785248 B1 [Patent Document 7] International Publication No. 2015 128278 A1

[0015] Summary of the Invention [Problem to be solved by the invention]

[0016] It is an object of the present invention to provide an acetylene carbon black composition recovered from a vulcanization bladder compound that exhibits at least similar, and preferably even better, vulcanization performance, particularly with respect to thermal conductivity and vulcanization time.

[0017] Another object of the present invention is to develop a process for recovering acetylene carbon black from vulcanization bladders containing acetylene black that is sustainable in the sense that the recovery produces low carbon dioxide emissions and the by-products provide additional environmental benefits, particularly compared to producing acetylene carbon black from acetylene. [Means for solving the problem]

[0018] The first task of the present invention relates to a filler composition comprising or consisting of (a) acetylene carbon black, (b) zinc and / or zinc compounds, and optionally (c) ash.

[0019] Ash content is generally the residue remaining after a material is subjected to high-temperature treatment in an oxygen-containing atmosphere, i.e., the amount of inorganic non-combustible material in a sample. For example, carbon black can be tested using a method in accordance with ASTM D 1506-2015.

[0020] A feature of the present invention is the presence of zinc, a component included in all vulcanization bladders, in the filler composition. The zinc can be present in the form of metallic zinc. Alternatively, a zinc compound can also be present, the compound being selected from the group consisting of zinc oxide, zinc complex and coordination compounds, zinc aggregates with coke particles, and mixtures thereof. The ash can also contain zinc, for example, in the form of a zinc compound. The zinc compound may contain metallic zinc, for example, as a residue from the manufacturing process.

[0021] In practice, bladders are typically manufactured using acetylene carbon black and a zinc compound (preferably ZnO) to reduce the curing time. However, applicants have surprisingly discovered that by using equal amounts of acetylene carbon black and zinc and / or zinc compounds, the filler composition of the present invention significantly reduces the curing time even more than prior art mixtures containing separate carbon black and zinc components.

[0022] Another advantage of the present invention is that the filler composition has improved thermal conductivity and fewer defects compared to similar filler compositions.

[0023] This represents an inhomogeneity in the composition that reduces the quality of the product. In fact, the filler composition of the present invention can be used without further reprocessing and can easily be substituted for fresh acetylenic carbon black at an equal weight percentage to the acetylenic carbon black in the filler composition.

[0024] This production process is also characterized by a lower carbon dioxide emission compared to the production of fresh carbon black. Furthermore, the gas mixture produced during pyrolysis can be used for energy generation and to operate pyrolysis furnaces. Compared to other pyrolysis processes, especially the pyrolysis of used tires, the resulting gas contains a significantly higher hydrogen content and a lower methane content, resulting in a higher calorific value. [Brief explanation of the drawings]

[0025] [Figure 1] A photo of small pieces of shredded rubber sheet. [Figure 2] Graph showing the progress of reactor temperature versus desired core temperature. [Figure 3] Temperature curves of the core temperature and the outflow gas (before cooling by the heat exchanger), and a graph of the pressure change over time. [Figure 4] Photograph of solid residue. [Figure 5] Graph of average particle size distribution of crushed solid residue. DETAILED DESCRIPTION OF THE INVENTION

[0026] <Filler composition> In a preferred embodiment, the filler composition comprises (a) from about 60 to about 99.5 wt. %, preferably from about 75 to about 99.5 wt. %, and more preferably from about 85 to about 99.5 wt. % acetylene carbon black; (b) about 0.2 to about 10 wt. %, preferably about 0.4 to about 8 wt. %, of said zinc and / or zinc compounds; and Optionally, (c) about 0.5 to about 15% by weight, preferably about 1 to about 12% by weight, of ash, provided that the sum of these amounts equals 100% by weight. For convenience, it is emphasized that compositions resulting in a content greater than or less than 100% by weight are not included in the present invention. Based on the information provided herein, one of ordinary skill in the art can readily identify compositions that add up to 100% by weight without further investigation.

[0027] In the present invention, "ash" refers to solid pyrolysis products and / or coking products other than carbon black, particularly various salts. The zinc compound can be selected from the group consisting of metallic zinc, zinc oxide, zinc complexes and coordination compounds, aggregates of zinc and coke particles, and mixtures thereof.

[0028] In another preferred embodiment, the composition exhibits a characteristic specific surface area and filler structure. - a BET specific surface area in the range of about 25 to about 200 m2 / g; and / or - OAN ranging from about 80 to about 400ml / 100g. Here, the BET specific surface area is measured in accordance with ASTM D 6556-2021, and the oil absorption number (OAN) is measured in accordance with ASTM D2414-2022.

[0029] In another preferred embodiment, the filler composition comprises a ground product having a particle size of 15 μm or less, as analyzed by laser diffraction in accordance with ISO 13320:2020.

[0030] The present invention also provides a filler composition obtainable by the following steps: (a) preparing a vulcanization bladder; (b) pyrolyzing the bladder to obtain a product mixture consisting of a solid residue, an oil fraction, and a gas fraction; (c) removing the oil and gas fractions from the solid residue; and (d) grinding and / or pelletizing the solid residue.

[0031] <Manufacturing process>

[0032] The present invention also provides a method for preparing a filler composition comprising or consisting of the following steps: (a) providing a vulcanization bladder containing acetylene black; (b) pyrolyzing the vulcanization bladder to obtain a product mixture comprising a solid residue, an oil fraction, and a gas fraction; (c) removing the oil and gas fractions from the solid residue; and (d) grinding and / or pelletizing the solid residue of step (c).

[0033] The thermal decomposition of organic matter in the absence of oxygen is called pyrolysis. During pyrolysis, polymer chains and cross-links are broken down into shorter fragments. These fragments are reassembled according to the chemical composition and structure of the molecules. The main gases evolved are CO2, CO, H2, CH3, and various hydrocarbons. In addition to the remaining solid residue, an oil-vapor mixture is formed. The condensable components are produced as pyrolysis oil, while the non-condensable components exist as pyrolysis gas. Thus, three groups of substances are formed: pyrolysis coke, pyrolysis oil, and pyrolysis gas. Their composition and distribution are determined by the process temperature and heating rate.

[0034] Pyrolysis of rubber materials typically begins at a temperature of 270°C. During pyrolysis, polymer chains are decomposed into shorter fragments. Random fragmentation occurs as a result of heat exposure. Fragments of varying average lengths are formed, and the length decreases with increasing temperature. At low temperatures, primarily kerosene, olefins, and aromatic compounds are produced. In contrast, at high temperatures, lighter oils and gases, such as hydrogen, methane, and heavy hydrocarbons, are produced. Because most rubber compounds contain carbon black, even complete decomposition results in a solid residue. Higher decomposition temperatures promote the production of pyrolysis gases and reduce oil yield. Product distribution changes with increasing temperature and heating rate, with increasing gas yield and H2 concentration. Detailed information on the pyrolysis procedure is described in European Patent 2427533B1 and European Patent 2661475B1 (both assigned to Pyrum Innovations). However, pyrolysis is preferably carried out at a temperature range of about 300 to about 1,000°C, preferably about 400 to about 650°C. The temperature is preferably increased at a rate of 100°C / 15 min until the maximum temperature is reached. Pyrolysis is usually complete within 30 to 100 min, but it is recommended to continue the process at elevated temperatures for an additional 100 to 250 min to ensure all volatiles have been outgassed. The solid residue can be separated from the pyrolysis oil, for example by filtration, and then subjected to washing and drying steps. The pyrolysis gases are sent to a furnace and burned to generate the energy needed to heat the pyrolysis furnace.

[0035] <Industrial applications> Another object of the invention relates to a compound comprising or consisting of: (a) at least one synthetic and / or natural vulcanizable rubber or polymer; (b) the filler composition described above.

[0036] In a first preferred embodiment, the compound comprises: The thermal conductivity at 25°C or 150°C is in the range of about 0.15 to about 0.5, preferably about 0.15 to about 0.4, and more preferably about 0.2 to about 0.375 W / (m*K). Thermal conductivity should be measured in accordance with ASTM E 1461-2011.

[0037] In another preferred embodiment, the compound has a surface topography (TOPO) of less than 2% on cut specimens, more preferably 0.2 to 1.5%, and most preferably 0.1 to 1.4%. TOPO is a measure of filler dispersion determined by surface topography including Medaglia correction according to the procedure described in A. Wehmeier, "Filler Dispersion Analysis by Topography Measurements," Technical Report TR 820, Degussa GmbH, and A. Wehmeier, "Entwicklung eines Verfahrens zur Characterisier-ung der Fullstoffdispersion in Gummimischungen mittels einer Oberflachentopographie," dissertation, 1998, University of Applied Sciences, Munster, and DE 1991 7975 C2. Also claimed is a method for reducing vulcanization time in the manufacture of rubber, tire, and / or vulcanization bladder compounds, comprising or consisting of the steps of: (a) providing a vulcanizable rubber or a blend of vulcanizable rubbers or polymers; (b) adding a filler composition as defined above; (c) vulcanizing the mixture of step (b); and optionally, (d) molding the vulcanized product to obtain a vulcanization bladder or other rubber article.

[0038] <Vulcanizable rubber and polymers> The term "vulcanizable rubber composition" refers to a composition that can be crosslinked by vulcanization to form a vulcanizate, with any combination of a rubber component and various additional components conventionally used in the rubber compounding art. The terms "crosslinking" and "vulcanization" are used interchangeably throughout this specification, unless otherwise specified, and refer to a chemical reaction that bonds polymer chains together with a crosslinking or vulcanizing agent.

[0039] The vulcanizable rubber component suitable for use in the vulcanizable rubber composition can include one or more gums containing olefinically unsaturated groups, i.e., diene-based rubbers or elastomers. The terms "rubber" and "elastomer" are used interchangeably throughout this specification unless otherwise specified. The rubber component can also include a mixture of a rubber containing olefinically unsaturated groups with other polymeric materials that do not contain such unsaturated groups, such as thermoplastic or thermosetting polymers. Preferably, however, the rubber component contains only one or more rubbers containing olefinically unsaturated groups. The terms "rubber containing olefinically unsaturated groups" and "diene-based rubber" are used interchangeably and are intended to include both natural and synthetic rubbers, or mixtures thereof.

[0040] Natural rubber can be used in its raw form and in various processed forms conventionally known in the rubber processing art. Synthetic diene-based rubber is any rubber containing at least one diene-based monomer, which alone or in combination with other monomers constitutes the rubber. Examples of diene-based rubber materials suitable for the practice of the present invention include, but are not limited to, natural rubber, emulsion styrene butadiene rubber, solution styrene butadiene rubber, polybutadiene, polyisoprene, ethylene propylene diene rubber (EPDM), butyl rubber, halogenated butyl rubber, acrylonitrile butadiene rubber, hydrogenated acrylonitrile butadiene rubber, polychloroprene, or any combination thereof. The rubber composition according to the present invention can also contain one or more non-diene rubber materials. Examples of non-diene-based rubber materials suitable for the practice of the present invention include, but are not limited to, ethylene propylene rubber (EPM), chlorinated polyethylene, chlorosulfonated polyethylene, acrylate rubber, ethylene vinyl acetate rubber, ethylene acrylic rubber, epichlorohydrin rubber, silicone rubber, fluorosilicone rubber, fluorocarbon rubber, or any combination thereof. Suitable rubbers also include functionalized rubbers and silicon- or tin-bonded rubbers. For example, the rubber can be functionalized with amine, alkoxy, silyl, thiol, thioester, thioether, sulfanyl, mercapto, sulfide, or other functional groups, or combinations thereof. The one or more functional groups can be primary, secondary, or tertiary, and can be located at one or both ends of the chain (e.g., α-, ω-functionalization), pendant from the polymer backbone, and / or within the polymer backbone. The rubbers of the present invention can also be partially crosslinked. Thus, a portion of the polymer chains of the rubber material can be crosslinked, with or without a coupling agent, before use in a vulcanizable rubber composition. Furthermore, the polymer material can be supplied in any form, but is typically supplied as bales or chips. Preferably, the rubber component comprises a mixture of natural and synthetic diene rubbers. Specific rubber materials that can be used in the practice of the present invention include, but are not limited to, Butyl 301 and Byprene™ 110.

[0041] The vulcanizable rubber composition may contain the filler composition according to the present invention in an amount of from 5 to 100 phr, e.g., from 10 to 70 phr. As used herein, the term "phr" refers to parts by weight of each listed material per 100 parts by weight of rubber or elastomer.

[0042] The vulcanizable rubber composition of the present invention may optionally further comprise at least one vulcanizing agent capable of inducing crosslinking of the rubber. Vulcanizing agents that can be used include any vulcanizing agent known in the art, such as phenolic resins.

[0043] The vulcanizable rubber composition may further contain one or more fillers, such as, for example, other carbon blacks, silica, organic silica, carbon nanotubes, carbon fiber, graphite, metal fiber, etc. Useful carbon blacks in this regard include ASTM grade carbon blacks selected from the 100 to 900 series as classified according to ASTM D1765. It is highly recommended to use acetylene black instead of furnace black for bladder vulcanization. Acetylene black improves the thermal conductivity of the compound.

[0044] The vulcanizable rubber composition of the present invention may further contain other known additives. Such additives include, for example, vulcanization aids such as primary vulcanization accelerators, secondary vulcanization accelerators, activators, and pre-vulcanization inhibitors; resins such as oils, tackifying resins, and plasticizers; softeners, fillers, waxes, peptizers; and anti-aging agents such as antioxidants and antiozonants. Useful primary and secondary vulcanization accelerators include, for example, guanidine, dicarbamate, dithiocarbamate, thiuram, thiourea, 2-mercaptobenzothiazole, benzothiazole sulfonamide, aldehyde amine, amine, disulfide, thiazole, xanthogenate, and sulfenamide. Specific examples include N-tert-butyl-2-benzothiazylsulfenamide, available commercially under the trade name Rhenogran TBBS-80 from Rhein Chemie Additives, and diphenylguanidine, available commercially under the trade name Rhenogran DPG-80. Suitable activators include zinc oxide and fatty acids such as stearic acid, lauric acid, palmitic acid, oleic acid, and naphthenic acid. The primary accelerator may be present in the composition in an amount ranging from 0.05 to 4 phr. The secondary accelerator, typically used in smaller amounts than the primary accelerator, may be present in the composition in an amount ranging from 0.05 to 3 phr.

[0045] Similar to the formulations used in the experimental section of this specification, other rubber compounds can also be resin crosslinked. A typical octylphenol and formaldehyde based resin for crosslinking butyl rubber is SP 1045 from Safic-Alcan.

[0046] The filler composition of the present invention can be advantageously used to prepare compounds containing a polymer matrix in which acetylene carbon black is dispersed. In addition to rubbers and elastomers, other organic resins, polymers, and other organic compounds can also be used as the matrix. Of course, the vulcanized rubbers and elastomers are particularly useful in the manufacture of end products such as tires and vulcanization bladders.

[0047] The filler compositions according to the present invention can be compounded and dispersed into the above-mentioned resin, polymer or rubber matrices using standard mixers and blenders, and, depending on the choice of resin, polymer or rubber system, can be heated, if possible, to facilitate uniform dispersion, using blenders, mixers, kneaders, or single or twin screw extruders known to those skilled in the art.

[0048] <Further Applications> The filler composition of the present invention, optionally after being crushed, granulated, or pelletized, functions to impart electrical and thermal conductivity to polymers or rubbers. Therefore, the composition can also be used as a conductive agent for batteries, such as primary batteries, secondary batteries, fuel cells, or compensators. It can also be used as an antistatic agent or a conductive agent for conductive paper. The filler composition of the present invention is particularly suitable for producing semiconductive shields for wire and cable applications. It can also be advantageously used in coating applications. Therefore, another object of the present invention is to use the filler composition as an additive in the manufacture of: battery; adhesives and sealants; and Conductive compounds, wire and cable.

[0049] The method can include a step of plasticizing the vulcanizable polymer component, for example, by stirring, before mixing the vulcanizable rubber component with the filler composition. To this end, the vulcanizable rubber component can be charged into a suitable device, for example, an internal mixer, and stirred for 2 minutes or less, for example, 1 minute or less, for example, 45 seconds. The filler composition and optionally further optional ingredients can then be added to the plasticized vulcanizable rubber component and mixed as disclosed above.

[0050] Mixing can be carried out using techniques and equipment conventionally known in the rubber processing art, such as mixers, stirrers, mills, kneaders, ultrasonic devices, dissolvers, shaker mixers, rotor-stator dispersion assemblies, high-pressure homogenizers, or combinations thereof. Preferably, mixers with intermeshing or tangential rotor configurations are used.

[0051] Mixing can include heating the components of the mixture to a temperature above room temperature if desired, but preferably occurs without imparting any additional heat to the mixture other than that generated by the mixing process itself.

[0052] After the first mixing step, the resulting mixture can be immediately subjected to a second mixing step, or a predetermined time can be allowed to pass between the two steps. The mixture can be left for a period of time ranging from a few minutes to several months, such as at least 60 minutes, or at least 12 hours. Prior to the second mixing step, the mixture can be transported to another mixing chamber and / or to another location, such as a customer.

[0053] After the first mixing step, or the second mixing step, if present, the method for preparing a vulcanizable rubber composition preferably further comprises adding to the mixture a vulcanizing agent, and optionally one or more activators, one or more accelerators, and additional ingredients conventionally used in the field of rubber compounding, as described above. The composition is then preferably mechanically stirred to at least partially, or preferably completely, mix the composition. Mixing is typically carried out at a temperature of 10°C to 140°C, more typically 80°C to 120°C, with constant stirring for less than 5 minutes, e.g., less than 3 minutes. Conditions, particularly rotor speed, can be selected such that the temperature of the mixture containing the crosslinking agent is less than 110°C.

[0054] Additionally, instead of being incorporated into an internal mixer, the vulcanizing agents can be incorporated into an open two-roller mill.

[0055] The present invention will be further illustrated by the following examples. In particular, the methods for measuring the specific properties of the acetylene carbon black defined above and in the claims are measured as shown in the experimental section below. [Example]

[0056] Example 1 Thermal decomposition of vulcanized bladders

[0057] To obtain the raw material for pyrolysis, a vulcanized bladder model compound was prepared using the formulation in Table 1. The rubber compound was mixed using a two-stage mixing process. A Werner & Pfleiderer GK1.5E mixer (chamber volume 1.58 liters, equipped with intermeshing mixing rotors) was used. The rotor speed was 45 rpm, and the chamber temperature was 60°C.

[0058] Table 1 Bladder Compound [Table 1] In the rubber chemical industry, parts per billion (phr) refers to the mass fraction of an individual compound component in an elastomer formulation. These figures are based on 100 parts by mass of the base polymer or base polymer (in the case of a polymer blend).

[0059] Ingredient Information Butyl 301 (butyl rubber, IIR) and Byprene 110 (chloroprene rubber, CR) from Ar-lanxeo Deutschland GmbH. Acetylene black used is Y200 BDS manufactured by Orion Engineered Carbons GmbH. Process oil P100 manufactured by Schill und Seil-lacher. ZnO from Arnsperger Chemikalien GmbH. · Octylphenol resole-based vulcanized resin SP-1045 manufactured by Safi-Alcan.

[0060] The chloroprene rubber and butyl rubber were mixed for 1 minute, and 35 phr of filler was added. After 90 seconds, the ram was raised and swept, and the remaining 15 phr of CB and process oil were added, followed by another 90-second mixing period. The ram was raised and swept again, and mixing continued for another 90 seconds. The compound was then added, cooled, and formed into a sheet using an open mill. Care was taken to ensure the mixing temperature did not exceed 160°C. After the mixture was left overnight, phenolic resin SP-1045 was mixed into the mixture using an open mill, and the mixing temperature was controlled below 110°C.

[0061] The 2 mm thick rubber sheets were then vulcanized for 30 minutes at 190°C. The sheets were then chopped into small pieces of approximately 1 to 5 mm (Figure 1) and subjected to the pyrolysis procedure.

[0062] Pyrolysis tests were conducted in a laboratory plant with a reactor volume of 1 L and a heating output of 1 kWel. The material was placed in a pyrolysis reactor, such as that disclosed in European Patent 2427533B1, and inerted along with the plant components. The material was then slowly heated to the target temperature, allowing for slow decomposition. Prior to the start of the experiment, a predetermined amount of rubber granules was added to the reactor, which was then attached and inerted along with all piping with nitrogen from a pressurized gas cylinder. To achieve this, nitrogen was first added and then vented via a ball valve. The experiment began with heating the reactor. The temperature of the insulated reactor was raised and maintained at the set temperature by a heating coil controlled by a temperature sensor inside the reactor. The pyrolysis gases released during pyrolysis were cooled to 5 °C in a heat exchanger. During this process, the fraction with a sufficiently low vapor pressure condensed and precipitated as pyrolysis oil in a laboratory bottle. The uncondensed pyrolysis gases were suctioned into a fume hood through a coalescing filter to remove aerosols.

[0063] A basic test was performed by adding the material to the reactor before the start of the test and subsequently heating the reactor with the sample material. The target temperature for pyrolysis was 650 °C, with a residence time of 1 hour. Figure 2 shows the general course of the basic experiment in terms of the applied reactor temperature and the desired core temperature. The starting material was fed into a cold reactor, which, after inerting, was continuously heated to the target temperature of 650 °C. The target temperature of the pyrolysis reactor was determined for this purpose. For this purpose, a target reactor temperature of 670 °C was selected. After reaching the target temperature, it was maintained for 1 hour to ensure complete pyrolysis reaction.

[0064] Figure 3 shows an example of the temperature curves of the core temperature and the effluent gas (before cooling by the heat exchanger) and the pressure over time. Here, the core temperature and gas temperature are seen to increase simultaneously, indicating that pyrolysis began early. It is noteworthy that during heating, the material temperature near the reactor wall was always higher than the core temperature. When the core temperature was 33°C and the wall temperature was 109°C, visible white mist formation was observed, which is partially attributed to water evaporation. When the core temperature was 61°C and the wall temperature was 220°C, condensation of pyrolysis oil was observed.

[0065] With further heating, the effluent gas temperature continued to increase, reaching a maximum of 139°C after a total of 49 minutes with a core temperature of 363°C. After the mass temperature reached 650°C, the gas temperature decreased to 60°C and remained constant until the reactor heater was turned off. This decrease in gas temperature indicated the completion of the pyrolysis reaction. After the mass temperature reached 650°C, it was held for 1 hour to remove volatiles and absorbed oil residue from the pyrolysis coke and ensure complete pyrolysis. The reactor pressure remained nearly constant throughout the test. Only a slight increase from 3 mbar to 5 mbar was observed during oil condensation. The pressure increased to 112 mbar after 180 minutes due to the introduction of nitrogen to purge the system. Table 2 shows the relevant mass balances for the test. The pyrolysis gas fraction was determined by calculation.

[0066] Table 2 Test Series Mass Balance [Table 2]

[0067] The majority of the rubber compounds were converted into pyrolysis gas, averaging 44.4%. Solid residue ("pyrolysis coke") was the next most abundant, averaging 37.1%. Pyrolysis oil production averaged 18.6%.

[0068] The solid residue, containing acetylene carbon black, ash, zinc, and coking products, was obtained as a black, porous solid (Figure 4). This material was generally flowable and easily removed from the reactor. The solid residues from all tests were combined to create a representative sample, which was then crushed in an impact crusher to avoid particle sizes exceeding 15 μm.

[0069] Table 3 shows the particle size measurement results of the ground solid residue. The grinding yield was 52%. A total of 390 g of ground solid residue was obtained. The average particle size distribution is shown graphically in Figure 5.

[0070] Table 3 Particle size distribution of the milled solid residue. Particle size was analyzed by laser diffraction according to ISO 13320:2020. [Table 3]

[0071] The resulting pyrolysis oil was a dark brown, low-viscosity liquid with a pungent sulfur-like odor. Upon further prolonged standing, the formation of a second, colorless, transparent liquid phase was observed, presumably process water, which is typically produced during the pyrolysis of rubber.

[0072] The composition of the pyrolysis gas clearly shows that hydrogen is the main component, averaging 42.6% by volume. The next most abundant component is methane at 16.7% by volume, followed by nitrogen at 5.7% by volume. Oxygen, carbon monoxide, and carbon dioxide each accounted for less than 2% by volume. Compared to the composition of pyrolysis gas from waste tires, the hydrogen content was significantly higher, and the calorific value was correspondingly higher.

[0073] <Analysis data of sample material> The properties of the sample material according to the present invention (filler composition, also called recovered acetylene black or rAB) are summarized in Table 4.

[0074] Properties of recovered acetylene black (rAB) [Table 4] <Measurement of characteristics> BET (BET specific surface area) was measured according to ASTM D-6556-19a. STSA (STSA specific surface area) was measured according to ASTM D-6556-19a. OAN structure was measured according to ASTM D-2414-21. Toluene transmittance (425 nm) was measured according to ASTM D1618-18. The pH value was measured according to ASTM 1512-21. Ash content was measured according to ASTM D 1506:2015. The carbon, hydrogen, nitrogen, and sulfur contents were determined according to DIN 51732:2014-07. The zinc content was determined by inductively coupled plasma optical emission spectroscopy (ICP OES). Prior to this, pressure-assisted microwave digestion was performed using, for example, microwaves and nitric acid. The determination was carried out according to ASTM D8371-20.

[0075] <Testing of recovered acetylene black in rubber> In the following study, the in-rubber properties of rAB (recovered acetylene black, filler composition) according to the present invention were compared with those of virgin acetylene black, carbon black recovered from used tires, and virgin standard furnace black.

[0076] The rubber compound was prepared using a two-stage mixing process. A HAAKE™ Rheomix kneader with a chamber volume of 0.379 L and tangential mixing rotors was used. The rotor speed was 50 rpm, and the chamber temperature was 65°C. The chloroprene and butyl rubbers were mixed for 1 minute, followed by the addition of 70% by weight of the filler and ZnO. After 90 seconds, the ram was raised and swept, and the remaining 30% by weight of the filler and process oil were added, followed by an additional 90 seconds of mixing. After another ram sweep, mixing continued for another 90 seconds. The compound was then dropped, cooled, and sheeted on an open mill. Care was taken not to exceed the mixing temperature of 160°C. The compound was left overnight, and then the phenolic resin was added on an open two-roll mill. Care was taken not to exceed the mixing temperature of 110°C. The vulcanizate was crosslinked at 190°C for 30 minutes.

[0077] <Example 2> Rubber properties Six different rubbers were prepared and vulcanized, and the rubber compositions are shown in Table 5.

[0078] Table 5 Rubber composition. Raw material concentrations are reported in phr. [Table 5]

[0079] Ingredient Information: Butyl 301 (IIR rubber) and Byprene 110 (chloroprene rubber) (manufactured by Arlanxeo Deutschland GmbH) CORAX™ N660 and CORAX™ N330 (manufactured by Orion Engineered Carbons GmbH) ·rCB ReOil RB615 (manufactured by Reoil Sp. z oo) Acetylene black (virgin) AB (Y200 BDS) (manufactured by Orion Engineered Carbons GmbH) SP-1045 (octylphenol resole cross-linked resin) (manufactured by Safi-Alcan) Procell Oil P100 (manufactured by Schill und Seillacher) ·ZnO (manufactured by Arnsperger Chemikalien GmbH)

[0080] Hardness was measured according to DIN 53505:2000-08.

[0081] Tensile strength, elongation at break, modulus at 100%, modulus at 200%, modulus at 300% and modulus at 500% were determined according to DIN 53504:2017-03.

[0082] Following crosslinking of the rubber compositions, the change in torque with crosslinking time was measured using a moving die rheometer (MDR 2000E) according to ISO 6502-3:2018.

[0083] The tear resistance was measured using notched angled specimens according to DIN ISO34-1:2016-09, method B, deformation (b), and the force required to enlarge the preformed notch was measured.

[0084] Thermal conductivity was measured in accordance with ASTM E1461-2011.

[0085] TOPO is a measure of filler dispersion determined by surface topography, including Medaglia correction, according to the procedures described in A. Wehmeier, "Filler Dispersion Analysis by Topography Measurements," Technical Report TR 820, Degussa GmbH, and A. Wehmeier, "Development of a method for characterizing the filler distribution in rubber mixtures by means of surface topography," dissertation, 1998, University of Applied Sciences, Munster, and DE 199 17975 C2.

[0086] Two carbon black grades, CORAX™ N660 and N330, are conventional furnace carbon blacks manufactured by the applicant and differ primarily in their specific surface area and structure. Product rCB (recovered carbon black) is a filler composition obtained by pyrolysis of passenger car and truck tires and was used for comparison, as were the other two examples. Filler composition rAB (recovered acetylene black) is in accordance with the present invention and was obtained by pyrolysis of vulcanized bladder compounds.

[0087] Product rAB contains 5.9 wt% zinc. Taking this into account, the amounts of Y200 BDS and zinc oxide were adjusted for C4, which contains virgin acetylene black. This means that compound C4 has an increased ZnO concentration and a decreased acetylene black concentration compared to C3, but the zinc and acetylene concentrations are similar to those of C6. The properties of the six rubbers are shown in Table 6.

[0088] A comparison of C1 (N660) and C2 (N330) shows that the thermal conductivity of the compounds is independent of the specific surface area. N660 has a nominal STSA of 34 m² / g, while N330 has an STSA of 76 m² / g, more than twice that. However, the thermal conductivities of compounds containing equal amounts of N330 and N660 are very similar, as shown in Table 6. C1 and C2 also exhibit lower thermal conductivities compared to C6, which contains the filler composition rAB according to the present invention.

[0089] Compound C4 (AB and ZnO adjusted) intentionally contains less acetylene black and more ZnO-based materials compared to C3 (AB). C4 was manufactured to investigate the effects of reducing the acetylene black content and increasing the ZnO-based material content in butyl rubber. However, when added alone, reducing the acetylene black and increasing the ZnO-based material content do not result in a shorter crosslinking time.

[0090] Surprisingly, compound C6, which incorporates the Zn component in the acetylene black filler composition, exhibits the shortest crosslinking time (tc80) and therefore the fastest crosslinking rate. This is reflected in the extremely short tc80 of only 14.54 minutes, and the difference between tc80 and tc5 of only 13.76 minutes.

[0091] Comparing the compounds containing fillers obtained from the recycling process C5 containing recovered carbon black rCB with C6 containing rAB, it can be concluded that the compounds containing the filler composition rAB of the present invention are superior in all aspects, including dispersion (very low TOPO value), crosslinking rate (short tc80), mechanical properties (high modulus at 300% elongation, high tensile strength, high elongation at break, and high tear resistance), and thermal conductivity.

[0092] Table 6 Intra-rubber properties of compounds listed in Table 5. [Table 6]

Claims

1. (a) acetylene carbon black; (b) zinc and / or zinc compounds, and optionally (c) ash; A filler composition comprising or consisting of:

2. 10. The composition of claim 1, (a) from about 75 to about 99.5 wt. % acetylene carbon black; (b) about 0.2 to about 10 wt. % of said zinc and / or zinc compounds; and and optionally (c) about 0.5 to about 15 weight percent ash. However, the total of these amounts must be 100% by weight.

3. 3. The composition of claim 1 or claim 2, A filler composition wherein said zinc and / or zinc compounds are selected from the group consisting of metallic zinc, zinc oxide, zinc complexes and coordination compounds, and aggregates of zinc and coke particles, and mixtures thereof.

4. 4. The composition according to any one of claims 1 to 3, a BET specific surface area in the range of about 25 to about 200 m / g, and / or an OAN in the range of about 80 to about 400 ml / 100 g, and / or A filler composition exhibiting a particle size of less than 15 μm.

5. (a) preparing a tire vulcanization bladder compound; (b) pyrolyzing the bladder compound to obtain a product mixture comprising a solid residue, an oil fraction, and a gas fraction; (c) removing oil and gas from the solid residue; and (d) milling and / or pelletizing the solid residue; The filler composition obtained by

6. (a) preparing a tire vulcanization bladder compound; (b) pyrolyzing the bladder compound to obtain a product mixture comprising a solid residue, an oil fraction, and a gas fraction; (c) removing oil and gas from the solid residue; and (d) milling and / or pelletizing the solid residue of step (c); A method for producing a filler composition comprising or consisting of:

7. 7. The method of claim 6, wherein the pyrolysis is carried out at a temperature ranging from about 300°C to about 1000°C.

8. 8. The method of claim 6 or claim 7, wherein the pyrolysis is carried out for a period ranging from about 30 minutes to about 350 minutes.

9. (a) at least one synthetic and / or natural vulcanizable rubber or polymer; (b) a filler composition according to any one of claims 1 to 5; and A compound containing or consisting of:

10. a thermal conductivity at 150°C in the range of about 0.15 to about 0.5 W / (m·K); and / or TOPO defect area is less than 2%; The compound of claim 9.

11. (a) providing a vulcanizable rubber or a blend of vulcanizable rubbers or polymers; (b) adding the filler composition of any one of claims 1 to 5; (c) vulcanizing the mixture of step (b); and, optionally, (d) molding the vulcanized product to obtain a tire or vulcanization bladder; 1. A method for reducing vulcanization time in the manufacture of rubber, tires and / or vulcanization bladder compounds, comprising or consisting of:

12. 10. Use of the filler composition according to claim 1 or claim 6 as an additive in the production of organic resins, polymers, vulcanizable rubbers and / or elastomers, in particular in the production of tires and / or vulcanizable bladder compounds.

13. Use of the filler composition according to claims 1 to 5 as an additive in the manufacture of batteries.

14. Use of the filler composition according to claims 1 to 5 as an additive in the production of adhesives and sealants.

15. Use of the filler composition of claims 1 to 5 as an additive in the manufacture of conductive compounds, wires and cables.

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