Modified fine particulate carbon material and method for producing the same

Abstract

The present invention relates to a fine particulate carbon material, a method for its manufacture and its use.

Description

[0001] The present invention relates to a subdivided modified particulate carbon material, a method for its manufacture and its use. BACKGROUND

[0002] Subdivided modified particulate carbon materials are used in many fields of application. These include applications as black colorants to applications as fillers in polymers, for example elastomers, thermoplastics or thermoplastic elastomers. Such carbon-based materials can be, for example, carbon black, i.e. materials with a relatively high proportion of carbon. Other particulate carbon materials are obtained from renewable raw materials. In comparison with carbon black, the proportion of carbon in such particulate carbon materials is slightly lower, but interesting properties are exhibited due to a high degree of functionalization. Particularly interesting starting materials for the manufacture of particulate carbon materials based on renewable raw materials are starting materials which can be completely or partially dissolved, for example sugars, starches or lignin. Such completely or partially dissolved starting materials based on renewable raw materials can be converted into particulate carbon materials by a precipitation process. Precipitation processes for the manufacture of dissolved particulate carbon materials are well known to the person skilled in the art.

[0003] For example, lignin-based particulate carbon materials can be obtained from lignin dissolved in, for example, liquid sodium hydroxide by precipitation by introduction of an acidic gas, such as CO2or H2S, or by addition of an acid, such as H2SO4. Examples of this prior art are given in WO 2006031175, WO 2006038863 or WO 2009104995.

[0004] In addition, lignin-based particulate carbon materials can be obtained from lignin dissolved in a base, for example liquid sodium hydroxide, by precipitation via stabilization while increasing the temperature to, for example, hydrothermal carbonization conditions. Examples of this prior art are described in WO 2016 / 020383 or WO 2017 / 085278. It is even possible to combine the methods by precipitation by introduction of an acidic gas, by addition of an acid or by increasing the temperature.

[0005] In the manufacture of particulate carbon materials, the adjustment of certain process parameters opens up the possibility of influencing, in particular, the particle size, i.e. the size of the agglomerates to be obtained which can be built up from primary particles, or the particle size distribution, and of adjusting the surface parameters, in particular the specific surface area, which is also used as a measure of the primary particle size.

[0006] The particle size or the particle size distribution can be quantified, for example, by sieve analysis or by laser diffraction. For example, sieve analysis can be carried out on dry particulate carbon materials in accordance with DIN 66165. For example, for particulate carbon materials dispersed in water, laser diffraction can be carried out in accordance with ISO 13320.

[0007] The primary particle size can be quantified, for example, by a specific surface area measurement method such as BET measurement or STSA measurement. Here, the BET measurement determines the sum of the outer surface area and the inner surface area, while the STSA measurement determines only the outer surface area. Suitable measurement methods are given, for example, in ASTM D 6556-14. In selecting the degassing temperature, it should be noted that it should be set at a value of about 150°C to check the particulate carbon material.

[0008] The average size or the size of the specific surface area of the primary particles is known to have an influence on the properties of a material manufactured using the particulate carbon material, for example, a rubber product manufactured by mixing the particulate carbon material with an elastomer, followed by crosslinking. For example, the wear properties of a rubber product differ depending on whether a particulate carbon material having a higher or lower BET surface area is used. The same applies to the case of mechanical properties such as tensile strength. A higher BET surface area value is associated with a higher tensile strength value and lower wear. Here, when a particulate carbon material is used, a specific surface area value of at least 5 m 2 / g, preferably at least 8 m 2 / g, more preferably at least 10 m 2 / g, further preferably at least 15 m 2 / g or more is generally required to obtain a high-quality rubber product.

[0009] However, a drawback of the known particulate carbon material obtained, for example, by precipitating a raw material based on a wholly or partially solubilized regenerated raw material, in particular a lignin-based particulate carbon material, is the unpleasant odor emitted from the particulate carbon material itself, released during the processing of the particulate carbon material, and / or emitted from a material containing the particulate carbon material. This severely limits the potential applications of the particulate carbon material, which is highly interesting in itself.

[0010] The unpleasant odor of the lignocellulose-based material is specifically caused by the thermal or chemical degradation processes of lignin, hemicellulose, and cellulose, and other wood components formed during wood processing, such as resins.

[0011] The compounds causing the unpleasant odor include sulfur-containing substances such as dimethyl sulfide, dimethyl disulfide, dimethyl trisulfide, or dimethyl tetrasulfide, or phenolic substances such as phenol, guaiacol, and ethyl guaiacol.

[0012] In addition, a plurality of volatile organic compounds are released. Volatile organic compounds, also referred to as VOCs, include volatile organic substances that readily vaporize or are already present as gases at lower temperatures, for example room temperature. The volatile organic compounds VOCs are either already present in the wood and are released from it during processing or, according to current knowledge, they are formed from the decomposition of fatty acids, which are decomposition products of the wood. Typical conversion products occurring during processing are, for example, higher aldehydes or also organic acids. Organic acids are produced in particular as decomposition products of the wood constituents cellulose, hemicellulose and lignin, wherein, among others, n-alkanoic acids such as acetic acid, propionic acid, hexanoic acid or also aromatic acids are formed. Aldehydes are formed from the basic building blocks of cellulose or hemicellulose during hydrolytic processing. Thus, for example, the aldehyde furfural is formed from the monosaccharides and disaccharides of cellulose and hemicellulose, respectively, and aromatic aldehydes can be released during partial hydrolytic digestion of lignin. Other aldehydes released are higher aldehydes such as hexanal, pentanal or octanal.

[0013] Methods for reducing the odor of lignin-based, particulate carbon materials are known from the prior art. On the one hand, these rely on a pre-purification of the lignin, for example by extraction processes (WO 2013 / 101397), enzyme-catalyzed reactions (DE 102006 057566), treatment with oxidizing components followed by washing (DE 10 1013 001678), on the other hand on the treatment of, for example, black liquor, by evaporation processes, treatment with reducing or oxidizing agents or also chlorination reactions and high-temperature treatment. However, these methods require the treatment of relatively large amounts of material or they involve the use of chemicals, which is disadvantageous both in terms of equipment and financial costs.

[0014] For example, a method for treating hydrothermally carbonized lignin at elevated temperatures is known from EP 3053929. In EP 3053929, the hydrothermally carbonized lignin is stabilized, preferably under inert gas, for the purpose of the final treatment, for example in activation. The hydrothermal carbonization is carried out at a temperature of 150 to 300°C, preferably 150 to 250°C. The stabilization is carried out at a suitable temperature which is at least 30°C higher than the temperature of the hydrothermal carbonization. The stabilization temperature is 200 to 700°C, preferably 300 to 600°C, ideally 500 to 600°C. Thus, a minimum stabilization temperature of 330°C results in a hydrothermal carbonization temperature of 300°C, and a stabilization temperature of 280°C results in a hydrothermal carbonization temperature of 250°C. Here, the heating rate is 0.1 to 20°C / min. During this process, gases, mainly oxygen and hydrogen, escape from the material, which are preferably evacuated during processing. The aim of this thermal treatment is to stabilize the hydrothermally carbonized lignin in such a way that it is ready for the final processing, preferably activation, to manufacture activated carbon.

[0015] For example, a method for reducing the odor of wood at elevated temperatures is known from EP 3 170 635 B1. In this process, long wood chips having a length of 150 to 200 mm, a width of 15 to 20 mm and a thickness of 0.5 to 2 mm are baked in an oxygen-poor or oxygen-free atmosphere at a temperature of 150 to 300 °C for a period of 1 to 5 hours. The mass loss is 10 to 30%.

[0016] It is therefore desirable to be able to provide a method which, without the use of further process chemicals, preferably by treating the already obtained particulate carbon material, enables targeted reduction of odors emanating from the particulate carbon material itself, released in the course of processing of the particulate carbon material and / or emanating from materials containing the particulate carbon material. In this way, the costs and work in terms of equipment can be reduced, while the amount of material to be processed is lower. However, a further requirement of such a process is that the desired properties of the particulate carbon material, such as the particle size or the particle size distribution or the primary particle size or the specific surface area, should not be lost in the course of the odor reduction treatment.

[0017] However, a further disadvantage of known particulate carbon materials, for example obtained by precipitation of a starting material based on complete or partial dissolution of a renewable raw material, in particular a lignin-based particulate carbon material, lies in its high polarity. This severely limits the possible applications of the particulate carbon material when it is used for materials having a significantly different polarity, the particulate carbon material itself being of high interest, in particular as an additive, reagent or filler.

[0018] It is therefore also desirable to be able to provide a method which enables selective adjustment of the polarity of the particulate carbon material, preferably by treating the already obtained particulate carbon material. In this way, the costs and work in terms of equipment can be reduced, while the amount of material to be processed is lower. However, a further requirement of such a process is that the desired properties of the particulate carbon material, such as the particle size or the particle size distribution or the primary particle size or the specific surface area, should not be lost in the course of the adjustment of the polarity.

[0019] Furthermore, the material loss should not be too high, since the particulate carbon material is already a valuable product.

[0020] Object of the invention

[0021] It is therefore an object of the present application to provide a corresponding particulate carbon material and a method for its manufacture, thereby enabling the provision of the above-mentioned particulate carbon material. SUMMARY

[0022] This object is achieved by the subject matter defined in the claims. Preferred embodiments and further aspects of the present application result from the embodiments described in the further claims and in the following detailed description.

[0023] Specifically, the first subject of this invention is a particulate carbon material having:

[0024] ο Above 0.20 Bq / g carbon but below 0.45 Bq / g carbon 14 C content,

[0025] D50 for particle size distributions less than 500 μm and greater than 0.5 μm, and

[0026] The density of OH groups is at least 0.05 mmol / g and at most 0.4 mmol / g, and wherein...

[0027] The solubility of the particulate carbon material in alkaline solution is less than 25%.

[0028] Another subject of the present invention is a method for manufacturing the particulate carbon material of the present invention, comprising at least two process steps, wherein, in a first process step, a precursor representing the particulate carbon material of the present invention and different therefrom, is provided, and subsequently modified in a second process step by heating in a gas atmosphere, thereby obtaining the particulate carbon material of the present invention, which preferably has reduced odor.

[0029] Another subject of the present invention is the use of particulate carbon materials as additives in polymer mixtures, particularly rubber mixtures, such as elastomer mixtures.

[0030] Another subject of the present invention is a vulcanizable rubber composition comprising at least one rubber and at least one filler component, wherein the filler component comprises at least the particulate carbon material of the present invention.

[0031] Another subject of the present invention is a vulcanizable rubber composition, which can be obtained by vulcanizing the vulcanizable rubber composition and has a swelling of less than 25% after 7 days in an alkaline solution. Detailed Implementation

[0032] The method of the present invention enables the production of finely granulated carbon materials with reduced odor and / or reduced OH groups (i.e., reduced polarity) and made from starting materials based on recycled raw materials. As mentioned above, such granulated carbon materials are another subject of the present invention.

[0033] The method of the present invention is characterized in that, for example, finely granulated carbon material (hereinafter referred to as pCM) is preferably obtained in a first process step, and its odor is reduced in a second process step, thereby obtaining pCM with reduced odor.

[0034] The process of the present invention is characterized in that, for example, a finely divided particulate carbon material (in the following: pCM) is obtained in a first process step, in a second process step its OH group density, in particular on the material surface, is reduced, preferably adjusted, whereby an OH group reduced pCM is obtained.

[0035] By the process of the present invention, a pCM with reduced odor and reduced, preferably adjusted, OH group density can also be obtained. In this regard, the second process step can combine the reduction of odor with the reduction, preferably adjustment, of the OH group density. In the following, modified pCM is to be understood as pCM with reduced odor or pCM with reduced OH group density, or pCM with reduced odor and reduced OH group density. Modified pCM or finely divided modified pCM thus denotes the particulate carbon material of the present invention obtained after the second process step. Finely divided pCM or pCM (both unmodified, respectively) thus denotes the precursor of the particulate carbon material of the present invention, obtained after the first process step and used for the second process step.

[0036] According to the present invention, the finely divided pCM is obtained in a first process step, preferably in the presence of a liquid, particularly preferably in the presence of water, and is converted into the modified pCM in a second process step, preferably in a gaseous atmosphere. According to the present invention, the separation of the liquid from the finely divided pCM is preferably carried out between the first and the second process step.

[0037] The particulate carbon material of the present invention (modified pCM) and its precursor (pCM) are preferably also referred to as "finely divided", respectively, in the context of the present invention. The term "finely divided" is defined in the following as a function of the BET surface area, the STSA surface area and the D50 of the particle size distribution, respectively. Particularly preferably, "finely divided" in the sense of the present invention means that the D50 (D50 value) of the particle size distribution of the respective particulate carbon material is less than 500 pm and greater than 0.5 pm. This fineness will also be referred to as PSD fineness, as defined in the following.

[0038] As mentioned above, the particulate carbon material of the present invention is preferably also referred to as "modified" particulate carbon material or modified pCM in the context of the present invention. In this sense, the term "modified" means that the carbon material is obtained from a finely divided particulate carbon material pCM which is different from the particulate carbon material of the present invention used as starting material. The particulate carbon material of the present invention differs from the finely divided particulate carbon material pCM used as starting material pCM in particular in that it can be obtained by heating the starting material in a gaseous atmosphere. By heating, the above-mentioned modification is achieved. In the context of the present invention, the particulate carbon material of the present invention is preferably also referred to as finely divided modified particulate carbon material. The above statement generally applies in this respect.

[0039] According to the present application, the morphology of the subdivided pCM is only slightly changed in the second process step. Therefore, the present process and the particulate carbon material of the present application are further characterized in that the subdivision of the modified pCM has essentially been achieved after the first process step. Therefore, the second process step of the present application is configured in such a way that the subdivision of the pCM is only slightly changed and that essentially only the odor of the subdivided pCM is reduced and / or the OH group density of the subdivided pCM is lowered or adjusted.

[0040] It has been shown to be advantageous if the BET surface area of the subdivided pCM after the first process step is at least 5 m 2 / g, preferably at least 8 m 2 / g, more preferably at least 10 m 2 / g, further preferably at least 15 m 2 / g, particularly preferably at least 20 m 2 / g, further preferably at least 30 m 2 / g, particularly at least 35 m 2 / g or more. Advantageously, the BET surface area is at most 200 m 2 / g, preferably at most 180 m 2 / g, more preferably at most 150 m 2 / g, particularly preferably at most 120 m 2 / g. In the following, the subdivision described in terms of the BET surface area will be referred to as the BET subdivision.

[0041] Advantageously, the BET surface area of the subdivided pCM only differs from its STSA surface area by at most 20%, preferably at most 15%, more preferably at most 10%. Therefore, the pCM preferably only has a low porosity. As an alternative to the measurement of the BET surface area, the STSA surface area can also be used. In the following, the subdivision described in terms of the STSA surface area will be referred to as the STSA subdivision.

[0042] Furthermore, it has been shown to be advantageous if the D50 of the particle size distribution of the subdivided pCM after the first process step is less than 500 pm, preferably less than 250 pm, more preferably less than 100 pm, particularly preferably 50 pm. Advantageously, the D50 of the particle size distribution of the subdivided pCM is more than 0.5 pm, more preferably more than 1 pm, particularly preferably more than 5 pm, further preferably more than 10 pm. D50 means that 50% of the particles are smaller than the indicated value. In the following, the subdivision described in terms of the PSD will be referred to as the PSD subdivision.

[0043] Therefore, the subdivision of the subdivided pCM and the modified pCM can be described by its PSD subdivision and / or its BET subdivision and / or its STSA subdivision.

[0044] One configuration of the process of the present application is characterized in that:

[0045] - in a first process step, obtaining a subdivided pCM in the presence of a liquid,

[0046] - in a second process step, converting it into a modified pCM in a gaseous atmosphere,

[0047] - between the first process step and the second process step, performing a separation of the liquid from the subdivided pCM,

[0048] - the subdivision of the modified pCM after the second process step is at most 5 times smaller than the subdivision of the subdivided pCM before the second process step, and / or

[0049] - the smell of the modified pCM after the second process step is reduced compared to the smell of the subdivided pCM before the second process step, and / or

[0050] - the OH group density of the modified pCM after the second process step is reduced compared to the OH group density of the subdivided pCM before the second process step.

[0051] During the second process step, the subdivision of the pCM is reduced by at most 5 times, preferably by at most 4 times, 3 times, 2.5 times, 2 times, 1.75 times, 1.5 times, 1.4 times, 1.3 times, 1.2 times, 1.1 times.

[0052] The reduction in subdivision means that:

[0053] - the D50 of the particle size distribution of the modified pCM is at most 5 times, preferably at most 4 times, 3 times, 2.5 times, 2 times, 1.75 times, 1.5 times, 1.4 times, 1.3 times, 1.2 times, 1.1 times larger than the D50 of the particle size distribution of the subdivided pCM, and / or

[0054] - the BET surface area of the modified pCM is at most 100%, preferably at most 5 times, preferably at most 4 times, 3 times, 2.5 times, 2 times, 1.75 times, 1.5 times, 1.4 times, 1.3 times, 1.2 times, 1.1 times smaller than the BET surface area of the subdivided pCM, and / or

[0055] - the STSA surface area of the modified pCM is at most 100%, preferably at most 5 times, preferably at most 4 times, 3 times, 2.5 times, 2 times, 1.75 times, 1.5 times, 1.4 times, 1.3 times, 1.2 times, 1.1 times smaller than the STSA surface area of the subdivided pCM.

[0056] Preferably, the factor by which the BET surface area or the STSA surface area is reduced in the second process step is smaller than the factor by which the D50 of the particle size distribution is increased in the second process step.

[0057] Furthermore, it has been shown to be advantageous if the ash content of the subdivided pCM after the first process step is less than 15 mass-%, preferably less than 12 mass-%, 10 mass-%, 8 mass-%, 6 mass-%, 5 mass-%, 4 mass-%, 3 mass-%, 2 mass-%. Advantageously, the ash content of the subdivided pCM is greater than 0.25 mass-%, preferably greater than 0.5 mass-%, more preferably greater than 0.75 mass-%.

[0058] Furthermore, the subdivided pCM preferably exhibits a carbon content of 40 to 80 mass-% (% by mass), preferably 50 to 80 mass-%, more preferably 60 mass-% to less than 80 mass-% (relative to ash-free dry matter (ash-free dry matter content)).

[0059] Furthermore, the subdivided pCM preferably exhibits an OH group density of at least 0.1 mmol / g, preferably at least 0.15 mmol / g, particularly preferably at least 0.2 mmol / g and at most 0.6 mmol / g, preferably at most 0.55 mmol / g, particularly preferably at most 0.5 mmol / g.

[0060] The subdivided pCM also preferably exhibits an OH group density of at least 1 OH / nm 2 BET surface area, preferably at least 1.5 OH / nm 2 BET surface area, particularly preferably at least 1.75 OH / nm 2 BET surface area and at most 15 OH / nm 2 BET surface area, preferably at most 12 OH / nm 2 BET surface area, particularly preferably at most 10 OH / nm 2 BET surface area. The determination of the OH group density on the surface of the material (both in mmol / g and in OH / nm 2 are carried out in accordance with Sipponen et al. (Determination of surface-accessible acidic hydroxyls and surface area of lignin by cationic dye adsorption; Bioresource Technology, 2014, 169: 80-87).

[0061] In the following, preferred embodiments of the first process step for obtaining the subdivided pCM will be described. In the context of the present application, it is irrelevant whether this first process step is carried out directly before the second process step or whether this first step is carried out significantly earlier in time than the second step (for example, such that the pCM from the first step is manufactured separately and then stored or transported before the second step is carried out).

[0062] Preferably, the finely divided pCM is obtained in the first process step by precipitating the starting material which is wholly or partially dissolved in a liquid.

[0063] To this end, the starting material is preferably wholly or partially dissolved in a liquid, preferably in water, prior to the first process step. More preferably, the starting material which is dissolved prior to the first process step consists of more than 50%, preferably more than 60%, 70%, 75%, 80%, 85% of sugars (carbohydrates), starch or lignin.

[0064] The determination of the sugar content is carried out in accordance with TAPPI T 249 cm-00.

[0065] The determination of the starch content is carried out in accordance with TAPPI T 419.

[0066] The determination of the Klason lignin content is carried out in accordance with TAPPI T 222 om-02. The determination of the acid-soluble lignin content is carried out in accordance with TAPPI T 250 UM 250. In the following, the sum of the Klason lignin and the acid-soluble lignin is referred to as the lignin content.

[0067] In the pulp industry, which processes large amounts of wood, liquids which contain lignocellulose and which are suitable, for example, as starting materials are produced, for example, as waste products. Depending on the method of wood processing, it produces large amounts of KRAFT lignin (usually dissolved in black liquor), hydrolytic lignin or lignosulfonate. Depending on the pH value in the respective processing method, the hydrogen atoms in the typical hydroxyl groups of lignin can be replaced in proportion by metal cations. Strictly speaking, lignosulfonate is already a chemical derivative of lignin, since it has introduced additional sulfonate groups during processing.

[0068] Thus, in one embodiment of the method, black liquor is used as the lignocellulose-containing liquid which is used as the starting material. Black liquor is a lignin-containing liquid which is produced as a waste liquid during the alkaline fractionation of biomass, for example, in the KRAFT process or the hydroxide process. The pH value of the black liquor is in the alkaline range, usually with a pH value of 12 to 14. In addition to lignin, the black liquor can also comprise other organic or inorganic constituents. Black liquor is characterized in that the proportion of lignin in the organic dry matter is higher than 50%, in particular higher than 60%, or even higher than 70%, and thus significantly higher than the proportion of lignin in woody biomass, i.e. 15% to 35%.

[0069] If the starting material consists of more than 50% of lignin, the finely divided pCM is preferably obtained by precipitating all or part of the lignin dissolved in the liquid by introducing an acidic gas and / or by adding an acid and / or by precipitation. Such methods are known in principle to the skilled person and are described in WO2006031175 or WO2006038863 or WO2009104995. Advantageously, these methods are controlled in such a way that after the first process step there is a finely divided pCM characterized by the above-mentioned particle size distribution, BET surface area and / or STSA surface area.

[0070] Alternatively, if the starting material consists of more than 50% of lignin, the finely divided pCM is preferably obtained by precipitation and simultaneous stabilization under hydrothermal carbonization (HTC) conditions. Such methods are known in principle to the skilled person and are described in WO2016 / 020383 or WO2017 / 085278 (precipitation and simultaneous stabilization). Advantageously, these methods are controlled in such a way that after the first process step there is a finely divided pCM characterized by the above-mentioned particle size distribution, BET surface area and / or STSA surface area.

[0071] Alternatively, the finely divided pCM is preferably obtained in the first process step by hydrolysis from a solid starting material, preferably from wood or straw. In this method, the solid starting material is comminuted before and / or during hydrolysis to such an extent that it exists after the first process step as a finely divided pCM characterized by the above-mentioned particle size distribution, BET surface area and / or STSA surface area. Since the carbohydrates contained in the starting material go into solution during hydrolysis, the finely divided pCM has an increased lignin content compared to the starting material. This finely divided pCM obtained by hydrolysis advantageously has a lignin content of more than 60% by mass, preferably more than 65% by mass, particularly preferably more than 70% by mass. Advantageously, these methods are controlled in such a way that after the first process step there is a finely divided pCM characterized by the above-mentioned particle size distribution, BET surface area and / or STSA surface area.

[0072] In the following, preferred embodiments of the second process step will be described. As described above, the finely divided pCM obtained after the first process step can be converted into the finely divided modified pCM of the present application by a second process step.

[0073] According to the present application, in the second process step the pCM is converted into a modified pCM in a gaseous atmosphere.

[0074] Advantageously, the second process step is not carried out under atmospheric air, but under a process atmosphere. By process atmosphere is understood, for example:

[0075] - air enriched with an inert gas, the oxygen content of which is less than 15 vol.%, preferably less than 10 vol.%, more preferably less than 5 vol.%, particularly preferably less than 3 vol.%; the absolute pressure of the air enriched with an inert gas can be selected as desired and is preferably at most 2000 mbar, more preferably at most 1500 mbar, and preferably at least 100 mbar, more preferably at least 200 mbar, 250 mbar, 500 mbar, 750 mbar.

[0076] - an inert gas; the absolute pressure of the inert gas can be selected as desired and is preferably at most 2000 mbar, more preferably at most 1500 mbar, and preferably at least 100 mbar, more preferably at least 200 mbar, 250 mbar, 500 mbar, 750 mbar.

[0077] - air at reduced pressure, the pressure of which is less than 750 mbar, preferably less than 500 mbar, more preferably less than 250 mbar, in some cases less than 100 mbar.

[0078] Advantageously, the oxygen content of the process atmosphere consisting of air enriched with an inert gas is at least 0.1 vol.%, preferably at least 0.5 vol.%, particularly preferably at least 1 vol.%.

[0079] In the sense of the present application, suitable inert gases are in particular nitrogen, carbon dioxide, superheated water vapor or a gas released from the pCM during the second process step. Although the gas released from the pCM during the second process step also comprises, for example, carbon monoxide, hydrogen, methane or hydrogen sulfide, etc., it is referred to as inert gas herein. When using air enriched with an inert gas or when using an inert gas as process atmosphere, the pressure can be selected as a function of the respective possibilities or requirements, as already indicated above. The simplest method in terms of equipment is to run the process at ambient pressure or at only slightly negative or positive pressure, for example ± 50 mbar, preferably ± 25 mbar, particularly preferably ± 10 mbar.

[0080] The second process step is preferably controlled in such a way (for example by selecting the temperature profile, the maximum temperature, the process atmosphere, possibly the pressure) that the mass loss of the pCM in the second process step is less than 20%, preferably less than 15%, more preferably less than 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3% or less. A certain mass loss is required during the second process step of the process of the present application in order to reduce the content of odoriferous substances and / or to reduce, preferably to adjust, the OH group density. This mass loss is usually at least 1% or more, preferably at least 2% or more, in some cases 5% or more. This ensures and achieves that not too much material is lost, on the one hand, and that the desired odor reduction and / or reduction of the OH group density is achieved, on the other hand. In this way, it can also be ensured that the modified pCM is suitable for use as a filler in, for example, an elastomer.

[0081] The process temperature in the second process step should exceed a minimum temperature and should not exceed a maximum temperature, regardless of the choice of the process atmosphere of the second process step. The maximum temperature is 300°C, preferably 250°C or less, more preferably 240°C, particularly preferably 235°C or less, further preferably 230°C or less, particularly preferably 225°C, in some preferred cases 220°C, further preferably 210°C, and in very few cases even 200°C or less. The minimum temperature is 80°C, preferably 100°C, preferably 120°C, preferably 130°C or more, more preferably 150°C or more, particularly preferably 160°C or more, particularly preferably 170°C or more, in some cases 180°C or more. The holding time in which the pCM is kept at the process temperature in the process atmosphere in the second process step can be chosen in a wide range. Suitable values are 1 second or more and 5 hours or less. Preferably, the holding time is 60 minutes or less, more preferably 30 minutes or less, particularly preferably 15 minutes or less, in some cases less than 10 minutes. For a continuous operation of the second process step, the holding time is to be understood as the average holding time.

[0082] Preferably, the OH group density of the subdivided pCM is adjusted during the second process step. Advantageously, this adjustment is carried out by choosing the process temperature, preferably in combination with the process atmosphere, particularly preferably by adjusting the oxygen content of the process atmosphere.

[0083] By combining a low process temperature, for example, preferably below 250°C, more preferably below 240°C, particularly preferably below 235°C or less, further preferably below 230°C, particularly preferably below 225°C, in some preferred cases below 220°C, further preferably below 210°C, and in very few cases even below 200°C, with an adjustment of the oxygen content, it is possible to adjust the OH group density purposefully without subjecting the material to high thermal stress. Thereby, the subdivision is maintained as much as possible, the odor is reduced as much as possible, and in addition, the OH group density is adjusted.

[0084] It has been found to be advantageous to not only treat the pCM in the process atmosphere for the holding time in the second process step, but also to carry out the heating and cooling under the process atmosphere.

[0085] If the pCM is obtained from softwood lignin, for example, by precipitation in combination with stabilization under hydrothermal carbonization conditions in the first process step, a mass loss of only 10% or less can be achieved using the second process step, for example, when the maximum temperature of the treatment is 250°C or less, while the BET surface area loss is about 5 m 2 / g or less (i.e., if the BET surface area of the pCM is 40 m 2 / g, it is reduced to a maximum of 35 m 2 / g). At the same time, smell tests show a significant reduction in the occurrence of unpleasant smells. This reduction is found not only in the pCM itself, which smells less, but also in the manufacturing process of rubber articles using the smell-reduced pCM, and in the rubber articles themselves (compared to other articles with pCM that has not been subjected to the second process step).

[0086] Thus, the process according to the present application can achieve a good balance between the desired minimization of smell and / or reduction of OH group density, while at the same time maximizing the desired material properties and quality loss. For this purpose, neither the use of process chemicals nor complex procedures is required. Furthermore, the maximum temperature of the treatment according to the present application is in a relatively low range, which is advantageous both in terms of costs and process control.

[0087] Preferably, the second process step is carried out in a moving bed, a fluidized bed or an entrained flow. More preferably, the second process step can be combined with a separation of the liquid. Advantageously, the separation of the liquid is carried out at least partially by evaporation thereof. Advantageously, the evaporation of the liquid is carried out preferably to a dry matter content of > 80%, preferably > 85%, so that the subdivided pCM reaches a temperature of at least 35°C, preferably at least 40°C, during the evaporation.

[0088] Advantageously, the evaporation of the liquid is carried out preferably to a dry matter content of > 80%, preferably > 85%, so that the subdivided pCM reaches a temperature of at most 130°C, preferably at most 125°C, more preferably at most 120°C, particularly preferably at most 115°C, further preferably at most 95°C, in particular at most 90°C, during the evaporation. Advantageously, the subdivided pCM is heated to the process temperature of the second process step only if its dry matter content is greater than 85 mass%, more preferably greater than 90 mass%, particularly preferably greater than 95 mass%.

[0089] As mentioned above, the modified pCM obtained according to the present application, preferably based on lignin and preferably obtained by precipitation or precipitation combined with stabilization, for example under hydrothermal carbonization conditions, is also proposed for use in rubber mixtures.

[0090] In the context of the present application, it has also been shown that the modified pCM manufactured according to the present application is also modified in terms of polarity or hydrophobicity and is, for example, more suitable for use in hydrophobic or low-polar elastomer compounds than pCM manufactured according to the prior art. Preferably, the elastomer compound with the modified pCM swells only conditionally in lye. Preferably, the mass increase of the elastomer compound with the modified pCM in the medium after 7 days is less than 25%, preferably less than 15%, more preferably less than 10%.

[0091] As mentioned above, the first subject of the present application is a modified pCM, i.e. a particulate carbon material having the following properties, in particular provided by the method of the present application:

[0092] o a C content higher than 0.20 Bq / g carbon but lower than 0.45 Bq / g carbon, 14 o a C content higher than 0.20 Bq / g carbon but lower than 0.45 Bq / g carbon,

[0093] o a D50 of the particle size distribution smaller than 500 pm and larger than 0.5 pm, and

[0094] o an OH group density of at least 0.05 mmol / g and at most 0.4 mmol / g, and wherein

[0095] o the solubility of the particulate carbon material in lye is less than 25%.

[0096] Preferably, the particulate carbon material of the present application has:

[0097] - a C content higher than 0.23 Bq / g carbon but preferably lower than 0.45 Bq / g carbon, 14 - a C content higher than 0.20 Bq / g carbon but lower than 0.45 Bq / g carbon,

[0098] - a carbon content of 60 to 80 mass-% relative to ash-free dry matter, and / or

[0099] - no glass transition temperature measurable according to DIN 53765-1994, and / or

[0100] - a volatile component content measured according to DIN 53552 at 950 °C of more than 30 mass-%, and / or

[0101] - a volatile component content measured according to DIN 53552 at 200 °C of less than 5 mass-%.

[0102] Advantageously, the BET surface area of the modified pCM is at least 5 m 2 / g, preferably at least 8 m 2 / g, more preferably at least 10 m 2 / g, further preferably at least 15 m 2 / g, particularly preferably at least 20 m 2 / g, further preferably at least 30 m 2 / g, in particular at least 35 m 2 / g or more. Advantageously, the BET surface area of the modified pCM is at most 200 m 2 / g, preferably at most 180 m 2 / g, more preferably at most 150 m 2 / g, particularly preferably at most 120 m 2 / g.

[0103] Advantageously, the BET surface area of the modified pCM differs from its STSA surface area by at most 20%, preferably at most 15%, more preferably at most 10%. Thus, the modified pCM preferably has only a low porosity.

[0104] The D50 of the particle size distribution of the modified pCM is less than 500 μm, preferably less than 250 μm, more preferably less than 100 μm, particularly preferably less than 50 μm. Advantageously, the D50 of the particle size distribution of the modified pCM is greater than 0.5 μm, preferably greater than 1 μm, particularly preferably greater than 5 μm, further preferably greater than 10 μm. Particularly preferably, the D50 of the particle size distribution of the modified pCM is greater than 5 μm, further preferably greater than 10 μm.

[0105] Advantageously, the ash content of the modified pCM is less than 15% by mass, preferably less than 12%, 10%, 8%, 6%, 5%, 4%, 3%, 2% by mass or less. Advantageously, the ash content of the modified pCM is greater than 0.25% by mass, preferably greater than 0.5% by mass, more preferably greater than 0.75% by mass. Particularly preferably, the ash content of the modified pCM is less than 4%, 3%, 2% by mass or less and greater than 0.25% by mass, preferably greater than 0.5% by mass, more preferably greater than 0.75% by mass.

[0106] Furthermore, the modified pCM exhibits an OH group density of at least 0.05 mmol / g, preferably at least 0.075 mmol / g, particularly preferably at least 0.1 mmol / g. The modified pCM exhibits an OH group density of at most 0.4 mmol / g, preferably at most 0.35 mmol / g, particularly preferably at most 0.3 mmol / g, in some cases less than 0.25 mmol / g, in very few cases less than 0.2 mmol / g.

[0107] The modified pCM is only conditionally soluble in a lye. The solubility of the modified pCM is less than 25%, preferably less than 15%, particularly preferably less than 10%. The solubility is determined according to the method described below. Preferably, the lye represents an aqueous NaOH solution, particularly preferably an aqueous solution having a concentration of 0.1 Mol / l.

[0108] The modified pCM preferably has a reduced odour. Thus, in particular the proportion of emissions of sulphur-containing substances and phenolic substances is reduced. It has also been possible, however, to reduce the emission of some VOCs, such as acetic acid. A method for determining the emission is described below.

[0109] Preferably, the proportion of dimethyl sulphide of the modified pCM is at most 1 mg / kg, preferably at most 0.5 mg / kg, more preferably less than 0.1 mg / kg, further preferably less than 0.05 mg / kg, particularly less than 0.01 mg / kg.

[0110] Preferably, the proportion of guaiacol and methylguaiacol (methoxycon) of the modified pCM is at most 1 mg / kg, preferably at most 0.5 mg / kg, more preferably less than 0.1 mg / kg, further preferably less than 0.05 mg / kg, in particular less than 0.01 mg / kg, respectively.

[0111] Preferably, the naphthalene content (DIN EN 16181 :2017-11 / Draft) of the modified pCM is less than 5 mg / kg. Preferably, the sum of the 18 EPA-PAHs without BG (DIN EN 16181 :2017-11 / Draft) is less than 5 mg / kg. Preferably, no benzo[a]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indenol[1,2,3-cd]pyrene, dibenzo[a,h]anthracene, benzo[ghi]perylene, benzo(e)pyrene and benzo[j]fluoranthene are detectable in the modified pCM (<0.1 mg / kg) (DIN EN 16181 :2017-11 / Draft).

[0112] Preferably, the modified pCM has a certain content of degasifiable individual components:

[0113] - 2-methoxyphenol

[0114] - phenol

[0115] - guaiacol

[0116] - 4-methoxy-3-methylphenol

[0117] - 4-propylguaiacol

[0118] - 2-methoxy-4-methylphenol

[0119] - 2-methoxy-4-ethylphenol

[0120] - 4-propylguaiacol

[0121] - methanol,

[0122] which is determined by thermal desorption analysis according to VDA 278 (05 / 2016) at less than 50 pg / g modified pCM, preferably 25 pg / g modified pCM, particularly preferably less than 15 pg / g modified pCM, further preferably less than 10 pg / g modified pCM, particularly preferably less than 5 pg / g modified pCM, in some cases less than 1 pg / g modified pCM, respectively.

[0123] Preferably, the OAN of the modified pCM is higher than 150 ml / 100 g, more preferably higher than 151 ml / 100 g, in particular higher than 151 ml / 100 g.

[0124] Preferably, the OAN of the modified pCM is lower than 200 ml / 100 g, particularly preferably lower than 180 ml / 100 g, in particular lower than 170 ml / 100 g.

[0125] Preferably, the electrical resistance of the SBR polymer mixture crosslinked by sulfur and filled with 120 phr of the modified pCM is higher than 1.0E10 Ω*cm.

[0126] Preferably, the modified pCM can be obtained by a method comprising at least two process steps, wherein in a first process step a precursor representing the particulate carbon material of the present application and a particulate carbon material pCM different therefrom is provided, which is subsequently modified in a second process step by heating under a gas atmosphere, whereby then the modified pCM, which is preferably odor-reduced, can be obtained.

[0127] Preferably, the D50 of the particle size distribution of the particulate carbon material pCM obtainable according to the first process step is less than 500 pm and more than 0.5 pm before heating in the gas atmosphere.

[0128] Preferably, the OH group density of the particulate carbon material pCM used is reduced or adjusted according to the second process step by heating in the gas atmosphere, whereby the modified pCM having an OH group density as defined above can be obtained.

[0129] Preferably, the second process step is not carried out under atmospheric air, but under a process atmosphere consisting of air enriched with an inert gas, the oxygen content of the air being less than 15 vol.%, preferably less than 10 vol.%, more preferably less than 5 vol.%, particularly preferably less than 3 vol.%, wherein the oxygen content is preferably at least 0.1 vol.%, particularly preferably at least 0.5 vol.%, more particularly preferably at least 1 vol.%.

[0130] Preferably, the particulate carbon material pCM provided in the first process step is obtained by precipitating a starting material, preferably a lignin-based starting material, which is wholly or partially dissolved in a liquid.

[0131] Preferably, the process temperature in the second process step is at most 50°C lower and at most 50°C higher than the temperature of the subsequent processing and / or the temperature of use, and the process temperature does not exceed the maximum temperature and does not fall below the minimum temperature.

[0132] Preferably, the D50 of the particle size distribution of the modified particulate carbon material obtainable after the second process step is at most 5 times, preferably at most 4 times, 3 times, 2.5 times, 2 times, 1.75 times, 1.5 times, 1.4 times, 1.3 times, 1.2 times, 1.1 times the D50 of the particle size distribution of the particulate carbon material pCM provided in the first process step.

[0133] A further subject of the present application is a process for the production of the particulate carbon material of the present application, said process comprising at least two process steps, wherein in a first process step a precursor representing the particulate carbon material of the present application and being different therefrom is provided and subsequently modified in a second process step by heating under a gaseous atmosphere, whereby then the particulate carbon material of the present application, which is preferably odor-reduced, is obtainable.

[0134] A further subject of the present application is the use of the particulate carbon material of the present application as an additive in a polymer mixture, in particular in a rubber mixture, such as an elastomer mixture.

[0135] A further subject of the present application is a vulcanizable rubber composition comprising at least one rubber and at least one filler ingredient, wherein the filler ingredient comprises at least the particulate carbon material of the present application.

[0136] The rubber composition can further comprise at least one vulcanization system comprising at least one crosslinking agent. Examples of such crosslinking agents are sulfur and / or peroxides. Examples of rubbers which can be used are natural rubber (NR), halogenated butyl rubber (again preferably selected from the group consisting of chlorinated butyl rubber (CIIR; chloro-isobutylene-isoprene rubber) and brominated butyl rubber (BIIR; bromo-isobutylene-isoprene rubber), butyl rubber or isobutylene-isoprene rubber (HR; isobutylene-isoprene rubber), styrene-butadiene rubber (SBR) (again preferably SSBR (solution polymerized SBR) and / or ESBR (emulsion polymerized SBR)), polybutadiene (BR, butadiene rubber), acrylonitrile-butadiene rubber (NBR, nitrile rubber) and / or HNBR (hydrated NBR), chloroprene (CR), polyisoprene (IR), ethylene-propylene-diene rubber (EPDM) and mixtures thereof.

[0137] A further subject of the present application is a vulcanized rubber composition, which is obtainable by vulcanizing the vulcanizable rubber composition and which has a swelling of less than 25 % after 7 days in caustic lye. Swelling is determined according to DIN ISO 1817:2015 in 0.1 mol NaOH.

[0138] Method of determination

[0139] 1. 14 Determination of C content

[0140] The carbon content is determined by the radio carbon method according to DIN EN 16640:2017-08. 14 Determination of the C content (biobased carbon content).

[0141] 2. Determination of the particle size distribution

[0142] The particle size distribution can be determined by laser diffraction of the material dispersed in water (1 wt.-% in water) according to ISO 13320:2009. For example, the volume fraction is specified as D50 in pm (50% of the sample volume has a particle diameter below this value).

[0143] 3. Determination of the carbon content

[0144] The carbon content is determined by elemental analysis according to DIN 51732:2014-7.

[0145] 4. Determination of the dry matter content

[0146] The dry matter content of the sample is determined according to DIN 51718:2002-06 as follows. For this purpose, a Sartorius MA100 moisture balance is heated to a drying temperature of 105°C. The dried sample, if not already in powder form, is pounded or ground to a powder. About 2 g of the sample to be measured is weighed on a suitable aluminum pan in the moisture balance and the measurement is started. As soon as the sample weight changes by no more than 1 mg within 30 seconds, the weight is considered constant and the measurement is terminated. The dry matter content then corresponds to the displayed content of the sample in wt.-%. At least one repeated determination is made for each sample. The weighted average value is reported.

[0147] 5. Determination of the ash content

[0148] The anhydrous ash content of the sample is determined by thermogravimetric analysis according to the DIN 51719 standard as follows: The sample is ground or pounded before weighing. The dry matter content of the weighed material is determined before the ash determination. The sample material is weighed in a crucible to the nearest 0.1 mg. The furnace, including the sample, is heated at a heating rate of 9°K / min to a target temperature of 815°C and then held at this temperature for 2 hours. The furnace is then cooled to 300°C and the sample is removed. The sample is cooled to ambient temperature in a desiccator and weighed again. The remaining ash is related to the initial weight, from which the weight percentage of the ash is determined. Three determinations are made for each sample, and the average value is reported.

[0149] 6. Determination of the BET and STSA surface area of the organic filler

[0150] The specific surface area is determined by nitrogen adsorption according to the standard ASTM D 6556 (2019-01-01) provided for industrial carbon black. According to this standard, the BET surface area (specific total surface area according to the Brunauer, Emmett and Teller method) and the external surface area (STSA surface area; statistical thickness surface area) are determined as follows.

[0151] The sample to be analyzed is dried at 105°C to a dry matter content > 97.5 wt.-% before the measurement. In addition, the measuring cell is dried in a drying oven at 105°C for several hours before the sample is weighed. The sample is then filled into the measuring cell using a funnel. In the case of contamination of the upper measuring cell shaft during filling, it is cleaned using a suitable brush or pipe cleaner. In the case of strongly flying (electrostatic) materials, glass wool is additionally weighed into the sample. The glass wool serves to hold any material that can fly up during the roasting process and contaminate the unit.

[0152] The sample to be analyzed is roasted at 150°C for 2 hours, the Al2O3 standard at 350°C for 1 hour. Depending on the pressure range, the following N2 amounts are used for the determination:

[0153] p / p0 = 0 - 0.01 : N2 amount: 5 ml / g

[0154] p / p0 = 0.01 - 0.5 : N2 amount: 4 ml / g.

[0155] For the determination of the BET, an extrapolation is carried out in the range of p / p0 = 0.05 - 0.3 with at least 6 measurement points. For the determination of the STSA, an extrapolation is carried out in the range of a layer thickness of the adsorbed N2 of t = 0.4 - 0.63 nm (corresponding to p / p0 = 0.2 - 0.5) with at least 7 measurement points.

[0156] 7. Determination of the solubility in alkaline medium

[0157] The determination of the alkaline solubility is carried out according to the following method:

[0158] 1. To determine the solubility of a solid sample, it must be present in the form of a dry, fine powder (dry matter content > 98%). If this is not the case, the dried sample is ground or thoroughly crushed before the solubility is determined.

[0159] 2. The solubility in three times was determined. For this, 2.0 g of the dry sample were weighed into 20 g of 0.1 M NaOH each. If, however, the pH value of the sample to be determined is < 10, the sample was discarded and 2.0 g of the dry filler were weighed into 20 g of 0.2 M NaOH each as an alternative. In other words, depending on the pH value (< 10 or > 10), either 0.1 M NaOH (pH > 10) or 0.2 M NaOH (pH < 10) was used.

[0160] 3. The alkaline suspension was shaken for 2 hours at room temperature at a shaking rate of 200 times per minute. If the liquid comes into contact with the lid during this process, the shaking rate must be reduced to prevent this.

[0161] 4. The alkaline suspension was then centrifuged at 6000 x g.

[0162] 5. The supernatant of the centrifugation was filtered through a Por 4 sieve plate.

[0163] 6. The solid after centrifugation was washed twice with distilled water by repeating steps 4 to 6.

[0164] 7. The solid was dried in a drying oven at 105 °C for at least 24 hours until the weight remained constant.

[0165] 8. The alkaline solubility was calculated as follows:

[0166] Alkaline solubility of the sample [%] = mass of the unsolubilized part after centrifugation, filtration and drying [g] * 100 / mass of the dry product obtained in item 2 [g]

[0167] 8. Determination of the pH value

[0168] The pH was determined according to the ASTM D 1512 standard as described below. The dry sample, if not already in powder form, was crushed or ground to a powder. In each case, 5 g of the sample and 50 g of completely deionized water were weighed into a glass beaker. The suspension was heated to a temperature of 60 °C under constant stirring using a magnetic stirrer with a heating function and stirrer and the temperature was maintained at 60 °C for 30 minutes. Subsequently, the heating function of the stirrer was deactivated so that the mixture could cool down under stirring. After cooling, the evaporated water was replenished by adding completely deionized water again and stirring for another 5 minutes. The pH value of the suspension was determined with a calibrated measuring instrument. The temperature of the suspension should be 23 °C (± 0.5 °C). Duplicate determinations were carried out for each sample and the average value was reported.

[0169] 9. Determination of the glass transition temperature

[0170] The measurement of the glass transition temperature was carried out according to DIN 53765-1994.

[0171] 10. Determination of the emission

[0172] The content of degasifiable organic compounds (emissions) was determined according to VDA 278 (05 / 2016) by thermal desorption analysis. The total degasifiable organic emissions are given as the sum of the measured values for VOC and FOG cycles. The concentration of individual components was determined by attributing signal peaks according to mass spectra and retention indices.

[0173] 11. Determination of the OH group density

[0174] The determination of the acidic hydroxyl groups available on the surface, including phenolic OH groups and phenoxide groups, was carried out qualitatively and quantitatively according to Sipponen by colorimetry. The method of Sipponen is based on the adsorption of the basic dye Sky Blue B to the surface-accessible acidic hydroxyl groups of the filler and is described in detail in the paper "Determination of surface-accessible acidic hydroxyls and surface area of lignin by cation dye adsorption" (Bioresource Technology 169 (2014) 80-87). The amount of surface-available acidic hydroxyl groups is given in mmol / g of filler.

[0175] The application will now be explained in more detail with reference to exemplary embodiments, however, without being limitingly explained.

[0176] Example 1 :

[0177] In a first step, a finely divided, particulate carbon material is manufactured from lignin by carrying out a hydrothermal treatment in water.

[0178] The material used for the first step is lignin UPM BioPiva 190 (commercially available). The solubility of the material used in 0.1 M NaOH is 68.5%.

[0179] The lignin is mixed with water under stirring, so as to be diluted to a dry matter content (DM content) of 11%. Then, 7.5 g of sodium hydroxide are added per 100 g of dry matter. The mixture is heated to 80°C under stirring and a lignin solution with a pH of 10.1 is obtained after 1 hour.

[0180] The lignin solution is then heated to 220°C and hydrothermally treated at 220°C for a period of 480 minutes. Subsequently, the obtained suspension is cooled to room temperature.

[0181] This results in a pH of 8.8.

[0182] The suspension sample was centrifuged at 12,000 rpm and the obtained residue was dried. The BET and STSA of the dried residue were analyzed. The measured multipoint BET was 39.4 m 2 / g and the STSA was 37.2 m 2 / g.

[0183] The obtained lignin suspension was then dewatered and pressed in a filter press, thereby mechanically dewatered to a DM content of 39.4%. In this way, a filter cake was obtained.

[0184] The D50 of the particle size distribution of a sample of the suspended solid matter of the filter cake was 5 pm.

[0185] The filter cake sample was dried. The BET and STSA of the dried filter cake were analyzed. The measured multipoint BET was 38.3 m 2 / g and the STSA was 36.1 m 2 / g.

[0186] The obtained filter cake represents a subdivided particulate carbon material pCM which is further processed (modified) in a second step.

[0187] In a second step, a subdivided modified particulate carbon material (according to the invention) is recovered from the subdivided particulate carbon material pCM by heating in a gaseous atmosphere.

[0188] From the subdivided particulate carbon material pCM obtained after the first step, samples were taken and treated in the second step under different conditions (samples 1 to 5), or not treated by the second step, but only dried in air (reference sample REF).

[0189] Each sample was individually fed into a rotary tube furnace which was continuously purged with nitrogen. With the specified gas composition set, the sample was first dried at a temperature of 80 °C, then heated to the process temperature shown in Table 1 below and held for the specified time. Then, the sample was again cooled to ambient temperature.

[0190] Table 1:

[0191]

[0192] The respectively obtained subdivided particulate carbon materials were then analyzed. The parameters given in Table 2 below were measured:

[0193] Table 2:

[0194]

[0195] Samples 1-5 and reference REF were mixed into the EPDM matrix as fillers, respectively. After vulcanization, the test specimens were swollen in aqueous NaOH solution (0.1 M). The swelling after 7 days is shown in Table 3 below. The swelling was determined according to DIN ISO 1817:2015:

[0196] Table 3:

[0197]

[0198] The lower the solubility of each sample determined in 0.1 % NaOH (see Table 2), the lower the swelling of the vulcanized products containing each sample as filler determined in aqueous NaOH solution.

[0199] The preparation of the mixture of compounds and the preparation of the vulcanized products were carried out according to the formulations of Table 4 and by the following process:

[0200] Table 4:

[0201]

[0202] The preparation of the mixture was carried out according to the following method: the mixture was prepared by means of a W&P GK 1.5E mixer (intermeshing rotor geometry), with a filling rate of 70%, a mixing temperature of 40 °C and a speed of 40 rpm.

[0203] The vulcanization was carried out by baking at 160 °C, according to the optimum t90 time determined in the rheometer.

Claims

1. A particulate carbon material, characterized by, having o above 0.20 Bq / g carbon but below 0.45 Bq / g carbon 14 C content, o a particle size distribution with a D50 of less than 500 pm and more than 0.5 pm, and o an OH group density of at least 0.05 mmol / g and at most 0.4 mmol / g, and o a solubility in lye of less than 25 mass-%, wherein the granular carbon material has a content of dimethyl sulfide, guaiacol and methylguaiacol of less than 1 mg / kg each.

2. The particulate carbon material of claim 1, wherein having an ash content of less than 15 mass-% and more than 0.25 mass-%.

3. The particulate carbon material of claim 2, wherein having an ash content of less than 12 mass-%.

4. The particulate carbon material of claim 2, wherein having an ash content of less than 10 mass-%.

5. The particulate carbon material of claim 2, wherein having an ash content of less than 8 mass-%.

6. The particulate carbon material of claim 2, wherein having an ash content of less than 6 mass-%.

7. The particulate carbon material of claim 2, wherein having an ash content of less than 5 mass-%.

8. The particulate carbon material of claim 2, wherein having an ash content of less than 4 mass-%.

9. The particulate carbon material of claim 2, wherein having an ash content of less than 3 mass-%.

10. The particulate carbon material of claim 2, wherein having an ash content of less than 2 mass-%.

11. The particulate carbon material of claim 2, wherein having an ash content of more than 0.5 mass-%.

12. The particulate carbon material of claim 2, wherein having an ash content of more than 0.75 mass-%.

13. The particulate carbon material according to claim 1 or 2, wherein having an ash content of less than 4 mass-% and more than 0.25 mass-%.

14. The particulate carbon material of claim 13, wherein having an ash content of less than 3 mass-%.

15. The particulate carbon material of claim 13, wherein having an ash content of less than 2 mass-%.

16. The particulate carbon material of claim 13, wherein having an ash content of more than 0.5 mass-%.

17. The particulate carbon material of claim 13, wherein having an ash content of more than 0.75 mass-%.

18. The particulate carbon material of claim 1 or 2, wherein having a particle size distribution with a D50 of less than 250 pm and more than 0.5 pm.

19. The particulate carbon material of claim 18, wherein having a particle size distribution with a D50 of less than 100 pm.

20. The particulate carbon material of claim 18, wherein having a particle size distribution with a D50 of less than 50 pm.

21. The particulate carbon material of claim 18, wherein having a particle size distribution with a D50 of more than 1 pm.

22. The particulate carbon material of claim 18, wherein having a particle size distribution with a D50 of more than 5 pm.

23. The particulate carbon material of claim 18, wherein having a particle size distribution with a D50 of more than 10 pm.

24. The particulate carbon material of claim 1 or 2, wherein having a particle size distribution with a D50 of more than 5 pm.

25. The particulate carbon material of claim 24, wherein having a particle size distribution with a D50 of more than 10 pm.

26. The particulate carbon material of claim 1 or 2, wherein having a solubility in lye of less than 15 mass-%.

27. The particulate carbon material of claim 26, wherein having a solubility of less than 10 mass-%.

28. The particulate carbon material of claim 1 or 2, wherein The lye denotes an aqueous NaOH solution of 0.1 mol / l, the solubility ratio is determined according to the method described in the description.

29. The particulate carbon material of claim 1 or 2, wherein having an OH group density of at least 0.075 mmol / g and at most 0.35 mmol / g.

30. The particulate carbon material of claim 29, wherein having an OH group density of at least 0.1 mmol / g.

31. The particulate carbon material of claim 29, wherein having an OH group density of at most 0.3 mmol / g.

32. The particulate carbon material of claim 1 or 2, wherein having o above 0.23 Bq / g carbon but below 0.45 Bq / g carbon 14 C content, and / or o no glass transition temperature measurable according to DIN 53765-1994, and / or o a carbon content of 60 mass-% to 80 mass-% relative to ash-free dry substance, and / or o a volatile content of more than 30 mass-% measured according to DIN 53552 at 950 °C, and / or o a volatile content of less than 5 mass-% measured according to DIN 53552 at 200 °C.

33. The particulate carbon material of claim 1 or 2, wherein a BET surface area of at least 5 m 2 / g, and the BET surface area is at most 200 m 2 / g.

34. The particulate carbon material of claim 33, wherein The BET surface area is at least 8 m 2 / g.

35. The particulate carbon material of claim 33, wherein The BET surface area is at least 10 m 2 / g.

36. The particulate carbon material of claim 33, wherein The BET surface area is at least 15 m 2 / g.

37. The particulate carbon material of claim 33, wherein The BET surface area is at least 20 m 2 / g.

38. The particulate carbon material of claim 33, wherein The BET surface area is at least 30 m 2 / g.

39. The particulate carbon material of claim 33, wherein The BET surface area is at least 35 m 2 / g.

40. The particulate carbon material of claim 33, wherein The BET surface area is maximum 180 m 2 / g.

41. The particulate carbon material of claim 33, wherein The BET surface area is maximum 150 m 2 / g.

42. The particulate carbon material of claim 33, wherein The BET surface area is maximum 120 m 2 / g.

43. A method of manufacturing the particulate carbon material of any one of claims 1 to 42, the method comprising at least two process steps, wherein, In a first process step, a precursor representing the granular carbon material according to any one of claims 1 to 42 and being different therefrom, pCM, is provided, which is subsequently modified in a second process step by heating under a gaseous atmosphere, whereby a granular carbon material according to any one of claims 1 to 42 can be obtained, which is reduced in odor.

44. The method of producing a particulate carbon material according to claim 43, wherein The D50 of the particle size distribution of the granular carbon material obtainable according to the first process step before heating under the gaseous atmosphere is less than 500 pm and more than 0.5 pm.

45. The method of producing a particulate carbon material according to claim 43 or 44, wherein The second process step is not carried out under atmospheric air, but under a process atmosphere consisting of air enriched with an inert gas, the oxygen content of the air being less than 15 vol.-% and the oxygen content being at least 0.1 vol.-%.

46. The method of producing a particulate carbon material according to claim 43 or 44, wherein The oxygen content of the air is less than 10 vol.-%.

47. The method of producing a particulate carbon material according to claim 46, wherein The oxygen content of the air is less than 5 vol.-%.

48. The method of producing a particulate carbon material according to claim 46, wherein The oxygen content of the air is less than 3 vol.-%.

49. The method of producing a particulate carbon material according to claim 46, wherein The oxygen content of the air is at least 0.5 vol.-%.

50. The method of producing a particulate carbon material according to claim 46, wherein The oxygen content of the air is at least 1 vol.-%.

51. The method of producing a particulate carbon material according to claim 46, wherein The particulate carbon material pCM provided in the first process step is obtained by precipitation of a starting material which is wholly or partially dissolved in a liquid.

52. The method of producing a particulate carbon material according to claim 43 or 44, wherein The starting material is a lignin-based starting material.

53. The method of producing a particulate carbon material according to claim 52, wherein The process temperature in the second process step is at most 50°C lower and at most 50°C higher than the temperature of the subsequent processing and / or the temperature of use, and the process temperature is not more than a maximum temperature and not less than a minimum temperature.

54. The method of producing a particulate carbon material according to claim 43 or 44, wherein The D50 of the particle size distribution of the modified particulate carbon material obtainable after the second process step is 5 times the D50 of the particle size distribution of the particulate carbon material pCM provided in the first process step.

55. The method of producing a particulate carbon material according to claim 43 or 44, wherein The D50 of the particle size distribution of the modified particulate carbon material obtainable after the second process step is at most 4 times the D50 of the particle size distribution of the particulate carbon material pCM provided in the first process step.

56. The method of producing a particulate carbon material according to claim 55, wherein The D50 of the particle size distribution of the modified particulate carbon material obtainable after the second process step is at most 3 times the D50 of the particle size distribution of the particulate carbon material pCM provided in the first process step.

57. The method of producing a particulate carbon material according to claim 55, wherein The D50 of the particle size distribution of the modified particulate carbon material obtainable after the second process step is at most 2.5 times the D50 of the particle size distribution of the particulate carbon material pCM provided in the first process step.

58. The method of producing a particulate carbon material according to claim 55, wherein The D50 of the particle size distribution of the modified particulate carbon material obtainable after the second process step is at most 2 times the D50 of the particle size distribution of the particulate carbon material pCM provided in the first process step.

59. The method of producing a particulate carbon material according to claim 55, wherein The D50 of the particle size distribution of the modified particulate carbon material obtainable after the second process step is at most 1.75 times the D50 of the particle size distribution of the particulate carbon material pCM provided in the first process step.

60. The method of producing particulate carbonaceous material according to Claim 55, wherein The D50 of the particle size distribution of the modified particulate carbon material obtainable after the second process step is at most 1.5 times the D50 of the particle size distribution of the particulate carbon material pCM provided in the first process step.

61. The method of producing a particulate carbon material according to claim 55, wherein The D50 of the particle size distribution of the modified particulate carbon material obtainable after the second process step is at most 1.4 times the D50 of the particle size distribution of the particulate carbon material pCM provided in the first process step.

62. The method of producing particulate carbonaceous material according to claim 55, wherein ​ 63. The method of producing particulate carbonaceous material according to claim 55, wherein The D50 of the particle size distribution of the modified particulate carbon material obtainable after the second process step is at most 1.3 times the D50 of the particle size distribution of the particulate carbon material pCM provided in the first process step.

64. The method of producing particulate carbonaceous material according to claim 55, wherein The D50 of the particle size distribution of the modified particulate carbon material obtainable after the second process step is at most 1.2 times the D50 of the particle size distribution of the particulate carbon material pCM provided in the first process step.

65. The method of producing particulate carbonaceous material according to claim 55, wherein The D50 of the particle size distribution of the modified particulate carbon material obtainable after the second process step is at most 1.1 times the D50 of the particle size distribution of the particulate carbon material pCM provided in the first process step.

66. Use of the particulate carbon material of any one of claims 1 to 42 or prepared according to the method of any one of claims 43 to 65 as an additive in a polymer mixture.

67. The use of claim 66, wherein, The polymer mixture is a rubber mixture.

68. The use of claim 66, wherein the compound is ###0010### The polymer mixture is an elastomer mixture.

69. A vulcanizable rubber composition comprising at least one rubber and at least one filler ingredient, wherein, The filler component comprises at least the particulate carbon material of any one of claims 1 to 42 or prepared according to the method of any one of claims 43 to 65.

70. A vulcanized rubber composition obtainable by vulcanizing the vulcanizable rubber composition according to claim 69, characterized in that, which shows a swelling of less than 25% after 7 days in lye. The polymer mixture is a rubber mixture. The polymer mixture is an elastomer mixture. The filler component comprises at least the particulate carbon material of any one of claims 1 to 42 or prepared according to the method of any one of claims 43 to 65. which shows a swelling of less than 25% after 7 days in lye.

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