WO2019016322A1

WO2019016322A1 - Thermally conductive polymers comprising carbon black material

Info

Publication number: WO2019016322A1
Application number: PCT/EP2018/069644
Authority: WO
Inventors: Daniele Bonacchi; Raffaele Gilardi; Marlene RODLERT-BACILIERI; Michael Spahr
Original assignee: Imerys Graphite & Carbon Switzerland Ltd.
Priority date: 2017-07-19
Filing date: 2018-07-19
Publication date: 2019-01-24

Abstract

The present disclosure relates to the field of carbon black materials which are inter alia employed as an additive in thermally conductive polymers. In particular, the present disclosure describes heat- treated (e.g., graphitized) carbon black materials which may be incorporated into a polymer matrix to yield polymer composite materials with desired thermal conductivity characteristics. The disclosure also provides methods of producing and using the carbon black materials as well as polymer composites comprising said graphitized carbon black materials. The disclosure further relates to methods of predicting the thermal conductivity of a polymer composite material comprising a given amount of a carbon black material or to methods of preparing a polymer composite material having a desired thermal conductivity.

Description

THERMALLY CONDUCTIVE POLYMERS COMPRISING CARBON BLACK MATERIAL

FIELD OF THE DISCLOSURE

[0001] The present disclosure relates to the field of carbon black materials which may be inter alia employed as an additive in thermally conductive polymers. In particular, the present disclosure describes heat-treated (e.g., graphitized) carbon black materials which may be incorporated into a polymer matrix to yield polymer composite materials with desired thermal conductivity characteristics. The present disclosure also provides methods of producing and using the carbon black materials as well as polymer composites comprising graphitized carbon black materials. The present disclosure further relates to methods of predicting or estimating the thermal conductivity of a polymer composite material comprising a given amount of a carbon black material and to methods of preparing a polymer composite material having a desired thermal conductivity.

BACKGROUND

[0002] The ability of a material to conduct heat is known as its thermal conductivity. Thermal conductivity itself is the transportation of thermal energy from high to low temperature regions.

Thermal energy within a crystalline solid is conducted by electrons and/or discrete vibrational energy packets. In the crystalline structures of a solid material, atoms excited into higher vibrational frequency impart vibrations into adjacent atoms via atomic bonds. This coupling creates waves which travel through the lattice structure of a material. In solid materials these lattice waves, or phonons, travel at the velocity of sound. During thermal conduction it is these waves which aid in the transport of energy. Each effect, phonons and movement of free electrons, contributes to the rate at which thermal energy moves. Generally, either free electrons or phonons predominate in the system.

[0003] Thermally conductive polymers are able to evenly distribute heat generated internally from a device and eliminate "hot spots". Possible applications for thermally conductive plastics include heat sinks, geothermal pipes, LED light sockets, heat exchangers, appliance temperature sensors, as well as many other industrial applications. Also, thermally conductive elastomers can be found in a wide variety of industrial applications such as gaskets, vibration dampening, interface materials, tire bladders and heat sinks.

[0004] Carbonaceous materials such as graphite powders, carbon black or coke are used in various technical fields, for example as filler (e.g., conductive additive) for thermally and/or electrically conductive polymers and other composite materials (e.g., heat sink materials) due to their unique chemical, thermal and conductive properties.

[0005] Graphite is useful for making polymers thermally conductive when electrical conductivity is also tolerated (or desired). It is generally understood that graphite operates by a phonon collision mechanism, different from the percolation mechanism that is understood to occur with metallic powders. This mechanism, together with the particular morphology of graphite particles, helps to meet a desired thermal conductivity at lower additive levels while avoiding abrasion issues. In addition, due to the particular structure of graphite, thermal conductivity tends to be different in the different directions of the particles. For example, it is generally more conducting along its layers {ab direction or "in-plane") and less conductive perpendicular to the layers (c direction or "through-plane"), e.g., because there is no bonding between the layers. In particular, expanded graphite is well known as a thermally and electrically conductive additive for polymers. High aspect ratio expanded graphite is generally thermally more conductive when compared to other carbon materials such as standard graphite or carbon fibers. However, the relatively low bulk density of expanded graphite complicates its use in polymers, including e.g., feeding into a polymer melt using common feeding/mixing technologies. Mechanical characteristics of the polymer composite materials obtained with graphite are also sometimes not satisfactory, especially at higher concentrations of the graphite in the material. Furthermore, in many applications, a high electrical conductivity is sometimes not desirable. [0006] Carbon black is the generic name for a family of small size, mostly amorphous or

paracrystalline carbon particles grown together to aggregates of different sizes and shapes.

[0007] Carbon black is generally formed in the gas phase by the thermal decomposition of hydrocarbons from various sources. The energy for the thermal decomposition can be taken by burning fuel like oil or gas, or by burning part of the feedstock used for the decomposition process with sub-stoichiometric amount of air. There are two principles for the thermal decomposition: the first is a thermal decomposition in the absence of oxygen, while the second is a thermal-oxidative

decomposition (incomplete combustion), see, for example, Kuhner G, Voll M (1993) Manufacture of Carbon Black. In: Donnet J-B, Bansal C and Wang M-J (eds) Carbon Black - Science and

Technology, 2^nd edn. CRC Taylor & Francis, Boca Raton-London-New York, ch. 1 , pp 1 -64. [0008] Carbon black may impart electrical conductivity to an insulating or semi-conductive polymer matrix. Usually the matrix percolates from a non- or low-conductive state to a conductive state at a concentration at which the conductive pathway in the matrix is established. Conductive carbon black grades achieve this so-called percolation effect at lower critical concentrations than conventional carbon black. This is related to their high carbon black structure which is established by the complex arrangement of the spherical primary particles to chemically bound branched or chain-like aggregate that again agglomerate to larger agglomerates by electrostatic forces. The void volume created by these agglomerated carbon black aggregates is a measure for the carbon black structure and can be characterized by the so-called oil absorption number (OAN). The carbon black structure in the compressed state of the carbon black material is characterized by a parameter called compressed oil absorption number (cOAN). The retention of the carbon black structure in the compressed state indicates the stability of the carbon black structure towards shear energy. The carbon black concentration to overcome the percolation threshold in a polymer matrix usually (inversely) dependent on the cOAN, i.e. it is lower with an increased cOAN. [0009] Carbon black materials have also been used to improve thermal conductivity of polymer composite materials (Demain, A., Issi, J. -P., Probst, N., 1993, Proceedings of 2^nd international conference on carbon black, Mulhouse, 233-236). The thermal conductivity was also shown to increase with increasing carbon black concentration (see also, e.g., WO 2005/028569 A2). [0010] As shown in EP 0 861 300 B1 or by Huagong Leji, 2014, 22(4): 1 -4, the degree of crystallinity, for example as expressed by the crystallite size L_c, can be increased by thermal treatments.

[001 1] However, a problem with increasing the thermal conductivity with increasing the concentration of the carbon black in the polymer is the observed increase in viscosity of the polymer matrix upon the addition of increasing amounts of carbon black. Thus, since carbon blacks are typically mixed into the polymer by compounding techniques (adding carbon black powder to the molten polymer) the increase in viscosity puts a practical limit on the amount of carbon black that can be added and mixed in homogenously into the polymer matrix. In general, highly structured carbon blacks, e.g. as indicated by a higher oil absorption number (OAN), lead to a higher viscosity increase or, in other words, such high-structure carbon blacks have a lower loading limit in the polymer matrix (thereby leading to a ceiling of achievable thermal conductivity of the polymer composite material).

[0012] Having regard to the situation as discussed above, there is a continuous need for novel carbon black materials (and polymer composite materials comprising such carbon blacks) that exhibit improved properties, particularly when used in the production of thermally conductive polymers.

SUMMARY [0013] The singular forms "a," "an," and "the" include plural reference unless the context dictates otherwise. The terms "approximately" and "about" refer to being nearly the same as the referenced number or value. As used herein, the terms "approximately" and "about" generally should be understood to encompass ± 5% of the specified number or value.

[0014] The carbonaceous materials disclosed herein may be added to a polymer to produce composite materials having a high thermal conductivity. In some embodiments, the thermal conductivity of such polymer composites may be as high as 1 W/m*k or even more, which is normally not obtainable with carbon black as an additive (such high thermal conductivities are typically only achieved with graphite as an additive).

[0015] Thus, in a first aspect, the present disclosure provides a carbon black material in particulate form that is characterized by a crystallite size L_c of greater than about 8 nm, or greater than about 10 nm, or greater than about 1 1 nm, or greater than about 12 nm, and wherein the material is further characterized by either an oil absorption number (OAN) of less than about 100 ml/100g; or less than about 75 ml/100g, or less than about 50 ml/100g; or by a BET SSA of less than about 30 m²/g, or less than about 20 m²/g, or less than about 15 m²/g, or less than about 12 m²/g, or less than about 10 m²/g, or both. Such carbon blacks can generally be obtained by heat-treatment of low-structure low surface area carbon blacks, which leads to a partial graphitization of the carbon black particles, leading to an increase in the crystallite size L_c compared to the untreated material.

[0016] Alternative advantageous carbon black materials provided by the present disclosure include carbon black particles characterized by a crystallite size L_c of about 3.5 nm to about 7.5 nm, or about 4.5 nm to 6.5 nm, wherein the material is further characterized by either an oil absorption (OAN) in the range of about 100 ml/1 OOg to 250 ml/100 g, or of about 150 ml/1 OOg to 220 ml/100 g; or a BET SSA of about 40 to 75 m2/g, or of about 50 to 65 m²/g, or both.

[0017] A further aspect of the disclosure relates to a composition comprising a mixture of one or more carbon black materials as defined in [0015], and, optionally, one or more carbon black material(s) as defined in [0016]. In other words, the present disclosure also includes mixtures of at least two different carbon black materials as described herein.

[0018] A method for producing such carbon black materials as described herein represents another aspect of the present disclosure. More specifically, an exemplary method for producing such carbon black materials as described herein comprises subjecting a carbon black starting material in particulate form to a temperature of between 1600°C and 3500° in the absence of reactive gases (in particular oxygen-containing gases) in a reactor until a carbon black material with the specified parameters is obtained.

[0019] Having regard to the thermal conductivity properties of the carbonaceous materials described herein, another aspect of the present disclosure relates to polymer composite materials which comprise a carbon black material in particulate form as described herein, or a composition comprising a mixture as described in [0017] (i.e. a mixture of one or more carbon black materials as defined in [0015] and one or more carbon black material(s) as defined in [0016]) dispersed in the polymer matrix, where such polymer composite materials can be further characterized by having a thermal conductivity of at least about 0.8 W/m*k, or at least about 0.9 W/m*k, or at least about 1 .0 W/m*k, or at least about 1 .1 W/m*k.

[0020] The present disclosure further comprises polymer composite materials comprising a graphitized carbon black material in particulate form characterized by a crystallite size L_c of above about 3.5 nm, or above about 4 nm, or above about 5 nm dispersed in the polymer matrix, provided the graphitized carbon black material in particulate form was not made in an electrothermal fluidized bed furnace.

[0021] Yet another aspect of the present disclosure relates to polymer composite materials comprising graphitized (e.g., heat-treated) carbon black in particulate form dispersed within the polymer matrix wherein the polymer matrix may be any polymer other than polypropylene. In some embodiments, the graphitized carbon black particles may further be characterized by any of the parameters described herein. [0022] The present disclosure also includes as another aspect methods for producing the polymer composite materials described herein which comprise mixing a graphitized carbon black material in particulate form as described herein with a polymer, wherein the polymer can be a thermoplastic polymer, a thermosetting polymer or an elastic (such as natural or synthetic rubbers). [0023] Yet another aspect of the present disclosure includes specific materials made of or comprising the polymer composite materials comprising the carbon black material described herein (which includes the compositions as defined in [0017]), such as materials for handling of electronic components such as carrier boxes, carrier trays, carrier tapes; films such as antistatic and conductive films, packaging films, garbage bags; materials used in the automotive industry such as fuel injection systems, anticorrosion systems, fuel tank inlets, electrostatically paintable parts; transport materials such as mobile phone parts, wheels, containers, bins, pallets; computer-related materials such as antistatic articles for computer & accessories, CD player; materials used in medical applications or in cleanroom equipments; articles for antistatic workplaces; antistatic flooring materials; heating elements, heat-sinks, heat exchangers, sensors, PTC switches, tire curing bladder, geothermal pipes, LED light sockets, appliance temperature sensors, gaskets, vibration dampening or interface materials; bipolar plates (for fuel cells), brake pads, carbon brushes, or polymer materials with increased UV protection and pigmentation. A related aspect relates to the use of carbon black materials in particulate form for making such materials as described above.

[0024] A further related aspect of the present disclosure includes the use of a carbon black material as described herein (which includes the compositions as defined in [0017]) to produce a polymer composite material having a high thermal conductivity, or to increase the thermal conductivity of a given polymer composite material (which may already include other additives to increase thermal and/or electrical conductivity such as graphite).

[0025] Yet another aspect relates to the use of carbon black material in particulate form as described in certain embodiments, particular low structure graphitized / heat-treated carbon black particles to produce polymer composites having a high carbon loading, such as at least about 35 wt%, or at least about 40 wt%, or at least about 45 wt%, or at least about 50 wt% of said carbon black material.

[0026] The use of a carbon black material in particulate form characterized by a BET SSA of less than about 75 m²/g, a crystallite size L_c of above about 4.0 nm, or above about 4.5 nm, or above about 5 nm, and, optionally, an OAN of below about 220 ml_/100g, or below about 220 mL/100g for preparing a polymer composite material having a through-plane thermal conductivity of at least about 1 W/m*k, or at least about 1.5 W/m*k, or at least about 2 W/m*k, or at least about 3 W/m*k represents another aspect of the present disclosure.

[0027] Finally, described herein is a correlation between the thermal conductivity and certain structural parameters of the carbon black material as well as its concentration in the polymer composite material. The present disclosure thus also comprises a method of predicting the (through- plane) thermal conductivity "k" of a polymer composite material comprising a carbon black material in particulate form dispersed in a polymer matrix, where the method comprises determining the OAN, the crystallographic L_c value and the loading concentration of the carbon black material in the polymer composite material, and calculating the thermal conductivity according to the formula k = A +

B*OAN*L_c*(loading concentration)², wherein A is the thermal conductivity of the polymer without additive, and B is a factor expressing the slope of the fitted straight line when plotting the thermal conductivity versus the value (OAN*L_c*(loading concentration)²), as for example illustrated in Fig. 5. The recognition of this correlation also offers the opportunity to calculate the loading concentration of a carbon black material for a desired thermal conductivity according to the correlation set out above and to prepare the polymer composite material having such a defined thermal conductivity by mixing the calculated amount of carbon black into the polymer matrix.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Fig. 1 illustrates the relation between the oil absorption number of the carbon black material and the observed (through-plane) thermal conductivity of a polypropylene composite material at 30wt% for different carbon blacks having a crystallite size L_c of around 2 nm and 5 nm, respectively. [0029] Fig. 2 illustrates the thermal conductivity increase versus the loading concentration for untreated as well as heat-treated (graphitized) carbon black E250G.

[0030] Fig. 3 shows the observed (through-plane) thermal conductivity of a polypropylene composite material at 30 wt% and 60wt% loading for different untreated and heat-treated carbon blacks (60% loading only achievable with low structure / low OAN carbon blacks such as N990 and N991 ). [0031] Fig. 4 shows a graph plotting the observed (through-plane) thermal conductivity of a polypropylene composite material at different loadings versus the factor of OAN and L_c (i.e. OAN* L_c) for a variety of carbon blacks. The thermal conductivity k of a polymer composite material was found to be a good fit when considered as a linear function of OAN*L_c.

[0032] Fig. 5 depicts a graph plotting the observed (through-plane) thermal conductivity of a polypropylene composite material versus the factor of OAN, L_c and loading² (i.e. (OAN*L_c*loading²)) for a variety of carbon blacks. The thermal conductivity k of a polymer composite material was found to be an even better fit when considered as a linear function of (OAN*L_c*loading²).

[0033] Fig. 6 illustrates the viscosity change upon increase of the loading concentration for various carbon blacks. It can be seen that for high structure (high OAN) carbon blacks, the viscosity increase above 30wt% loading quickly increases to unsustainable levels, preventing homogenous distribution within the polymer matrix (polypropylene). In contrast, the concentration of low structure / low OAN carbon blacks could be increased up to 60% (or even more) without a concomitant increase in viscosity (expressed as Torque values in Nm, see Materials and Methods section below). DETAILED DESCRIPTION OF THE DISCLOSURE

[0034] Polymer composite materials having high thermal conductivity, such as thermal conductivities of at least about 1 W/m*k, may be obtained using graphitized carbon black materials as disclosed herein. Such polymer composites may possess high thermal conductivity and may also maintain useful mechanical properties (such as impact strength). Accordingly, using the graphitized (i.e. heat- treated) carbon black materials as an additive in polymers may allow to produce polymer composite materials which are characterized by an excellent thermal conductivity while maintaining the desired mechanical properties, which is desirable in many technical fields where such composite materials are employed. [0035] The research of the present disclosure provides some new insights into the characteristics of carbon black materials that determine the thermal conductivity of polymer composite materials comprising these carbon blacks. Having regard to this research, the present disclosure also provides the possibility to allow the prediction of the resulting thermal conductivity of a polymer composite material at a given loading level or, related to this, to calculate the amount of carbon black additive for obtaining a composite material with a desired pre-determined thermal conductivity.

[0036] More specifically, described herein is the (partial) graphitization of carbon blacks (e.g., by subjecting the carbon black particles to a heat treatment in an inert atmosphere), including "low structure" carbon blacks (which are typically characterized by low oil absorption numbers (OAN) and relatively low surface area) that leads to modified carbon blacks which are characterized by a higher crystallinity (as indicated by a higher crystallite size L_c) as well as by a lower surface area and oil absorption compared to the untreated material. Such low structure graphitized carbon blacks may be added to a polymer matrix, e.g., in relatively large amounts, as they typically do not increase the viscosity of the (molten) polymer in the same manner as unmodified, e.g., higher structure, carbon blacks. For example, above around 30 to 35 wt%, the viscosity in the polymer may increase so much that a homogenous distribution of the carbon black powder within the matrix is no longer possible. In contrast, the graphitized, e.g., low structure, carbon blacks of the present disclosure may be added at higher loading levels without causing the viscosity increase observed for the other carbon blacks as described above. Since the thermal conductivity of a polymer composite is dependent on the loading level of the carbon black (which has shown a correlation with the loading level/concentration squared as discussed below), higher thermal conductivities may be achieved in the resulting polymer composite material using higher concentrations of such carbon blacks.

[0037] In addition, carbon blacks with a higher OAN may lead to a higher thermal conductivity for a given crystallinity (e.g., characterized by a similar L_c value) and fixed loading concentration (cf. Fig. 1 ). Figure 1 further illustrates an example wherein a higher crystallinity of the carbon black (as indicated by a higher crystallite size L_c) leads to higher thermal conductivity. Moreover, the thermal conductivity of polymer composites may increase with the loading level/concentration of the carbon black material in the polymer matrix. For example, Fig. 2 show conductivity increase data for a higher structure unmodified carbon black as well as the respective graphitized version of said carbon black with increased loading. Fig. 3 on the other hand illustrates that while higher structure carbon blacks generally lead to polymer composites having a higher thermal conductivity compared to their lower structure counterparts (such as the carbon blacks marked as N990 or N991 ), and while the thermal conductivity generally increases with higher crystallite size L_c, the viscosity increase observed for larger carbon black loading levels may put a practical limit on the achievable conductivity with such higher structure carbon blacks (e.g., topping out at below 0.8 W/m*K in the example shown in Fig. 3). In contrast, with low structure graphitized carbon blacks, loading levels of 60% were achieved, (see, e.g., Fig. 6 plotting the viscosity increase versus increasing loading levels for different carbon blacks), yielding composite materials characterized with thermal conductivities above 0.8 or even 1.0 W/m*K (cf. Fig. 3).

[0038] The present disclosure further indicates that the thermal conductivity of a polymer composite material at a given carbon black concentration can be plotted as a linear function of the factor OAN*L_c of the carbon black material in the polymer base (cf. Fig. 4). It was further found that the thermal conductivity k of the polymer composite material can be plotted as a function of the factor OAN* L_c "loading concentration². (with OAN, L_c and loading concentration all referring to the carbon black material mixed with the polymer matrix (see Fig. 5). In other words, even though the low OAN carbon blacks yield (at the same loading level) polymer composite materials with a relatively lower thermal conductivity compared to higher structured carbon blacks (e.g., having a higher OAN and typically also a higher BET SSA), it was found that the possibility to increase the loading level eventually trumps the decreased conductivity at the same concentration in the polymer. Moreover, the results (e.g. as illustrated in Figs. 2 and 3) support the observation that the heat treatment provides for carbon blacks with a higher crystallite size L_c (which as evident from the correlation above also increases the resulting thermal conductivity). Graphitized Carbon Blacks

[0039] Accordingly, in a first aspect, the present disclosure relates to a carbon black material in particulate form, characterized by a crystallite size L_c of greater than about 8 nm, or greater than about 10 nm, or greater than about 1 1 nm, or greater than about 12 nm, and wherein the material is further characterized by

i) an oil absorption number (OAN) of less than about 100 ml/100g; or less than about 75 ml/100g, or less than about 50 ml/100g; and/or

ii) a BET SSA of less than about 30 m²/g, or less than about 20 m²/g, or less than about 15 m²/g, or less than about 12 m²/g, or less than about 10 m²/g.

[0040] Thus, the carbon blacks according to some aspects of the present disclosure are

characterized by a relatively low oil absorption, which indicates carbon black aggregates of low structure (such as relatively little branching of the carbon black aggregates). Such low structure carbon blacks are at the same time typically characterized by a relatively low specific surface area (BET SSA), as described above. Accordingly, the particles of such carbon blacks may be

characterized either by a low OAN or a low BET SSA, or both.

[0041] In addition, the relatively high crystallite size L_c of at least 8 nm of such carbon black materials indicates that the material typically underwent a graphitization process, e.g., where the carbon black particles were subjected to a heat treatment at relatively high temperatures (typically between 1600 and 3500°C) in an inert atmosphere, as such large crystallite sizes are in general not observed for untreated carbon blacks (even those of low structure, such as N990 grades). On the other hand, the material obtained by the heat treatment is still a carbon black and not a graphitic material, such that the crystallite size L_c of the heat-treated carbon blacks is typically less than about 30 nm, or less than about 25 nm, or less than about 20 nm.

[0042] In some embodiments, the carbon black material of this aspect of the disclosure is a graphitized thermal carbon black. Thermal carbon black has, in the carbon black spectrum, typically the largest particle size and among the lowest degrees of particle aggregation or structure. Thermal carbon blacks may for example be derived from natural gas, where the process involving thermal decomposition of the gas in the absence of oxygen, which leads to high purity carbon blacks with low structure.

[0043] In some embodiments of this aspect of the disclosure, the carbon black material may be further characterized by a xylene density of generally more than 1.90 g/cm³, or more than 1.93 g/cm³, or more than 1.95 g/cm³, or more than 1.98 g/cm³, or in some instances even more than 2.00 g/cm³. In most embodiments the xylene density does not exceed about 2.20 g/cm³, hence certain embodiments may be characterized by a xylene density ranging from about 1 .90 g/cm³ to about 2.20 g/cm³, or from about 1.95 g/cm³ to about 2.20 g/cm³, or from about 2.00 g/cm³ to about 2.20 g/cm³.

[0044] The carbon black materials disclosed herein may in certain embodiments be further characterized, alternatively or in addition, by an interlayer distance c/2 of typically between about 0.3370 nm and about 0.3500 nm, or between about 0.3380 nm and about 0.3450 nm, or between about 0.3380 nm and about 0.3430 nm, or between 0.3390 to 0.3420 nm.

[0045] Alternatively or in addition, the carbon black materials described herein may be further characterized by a pressed density (determined at a pressure of 20 kN/cm²) of more than about 1.40 g/cm³, or more than about 1.45 g/cm³, or more than about 1.50 g/cm³. In some instances, the pressed density even exceeds 1.50 g/cm3 and may even reach values up to 1.80 g/cm³ or even 2.0 g/cm³ (see, e.g., Table 2 below).

[0046] The carbon black materials may in some embodiments be characterized, again alternatively or in addition, by a minimum void volume (1 - press density at 20 kN/cm²/ xylene density) * 100) of typically less than 20%, such as less than about 19%, or less than about 17%, or less than about 15%, or less than about 13%, or less than about 12%. For certain embodiments of this aspect, void volumes of less than 10% have been observed (cf. again Table 2). [0047] Moreover, the carbon black material as described herein is also typically characterized by a relatively low sulfur content as measured according to ASTM D1619. Sulfur is typically present as a contamination in carbon blacks and can be detrimental for some applications. Thus, in some embodiments the sulfur content of the carbon black materials described herein is typically less than about 100 ppm, or less than about 50 ppm, or less than about 30 ppm. Alternatively or in addition, the carbon black material is in some embodiments further characterized by a relatively low polycyclic aromatic hydrocarbon (PAH) content. Polycyclic aromatic hydrocarbons are composed of multiple aromatic rings lacking further branching substituents and are considered highly toxic, carcinogenic, and/or mutagenic. Thus, in some embodiments the polycyclic aromatic hydrocarbon (PAH) content of the carbon black materials described herein is less than about 1000 ppm, or less than about 800 ppm, or less than about 600 ppm, or less than about 400 ppm, or less than about 200 ppm or even less than about 100 ppm. In fact, certain carbon blacks as described herein may have an even much lower PAH content of less than 50 ppm, or less than 20 ppm, less than 10 ppm or even less than 5 ppm.

[0048] In some instances, the carbon black material may also be characterized by its functional properties it conveys when used as an additive in polymer composite materials. Thus, in certain embodiments, the carbon black material as described herein may be further characterized by a loading limit in polypropylene of at least 45 wt%, or at least 50 wt%, or at least 55 wt%, wherein the loading limit (expressed as wt% of the total polymer composite composition) is defined as the weight content of carbon black in a polypropylene matrix at which the torque level, measured at a temperature of 200° (where the polypropylene is in a molten state), is larger than 8 Nm, or larger than 9 Nm, or larger than 10 Nm (measurement conditions as described in the Materials and Method section below).

[0049] The loading limit will be determined as the concentration at which the torque level exceeds 10 Nm. It will be appreciated that in practice the actually achievable loading limit depends on the exact choice of polymer, the compounding conditions and devices employed for the compounding, but above a certain viscosity it may be increasingly difficult to homogenously distribute the carbon black particles within the polymer matrix.

[0050] In another aspect, the present disclosure also provides a carbon black material in particulate form that is characterized by a crystallite size L_c generally less than 7.5 nm, such as ranging from about 3.5 nm to about 7.5 nm, or from about 4.5 nm to 6.5 nm, or from about 5.0 nm to 6.0 nm, wherein the material is further characterized by

i) an oil absorption (OAN) of about 100 ml/1 OOg to 250 ml/100 g, or of about 150 ml/1 OOg to 220 ml/100 g, or of about 180 ml/1 OOg to 220 ml/1 OOg, or of about 190 ml/1 OOg to 210 ml/1 OOg, or of about 200 ml/1 OOg to 205 ml/1 OOg; and/or

ii) a BET SSA of about 40 to 75 m²/g, or of about 50 to 65 m²/g, or of about 55 to 60 m²/g.

[0051] In an embodiment of this aspect, the carbon black material is characterized by an L_c of 5 to 5.6 nm, an oil absorption of 200 ml/1 OOg to 205 ml/1 OOg; and a BET SSA of 55-60 m²/g. [0052] It was found that such carbon blacks may likewise be used as an additive to convey beneficial properties to polymer composite materials comprising said carbon black materials.

[0053] Yet another aspect relates to compositions comprising at least two different carbon black materials as described herein. For example, the present disclosure includes compositions comprising a mixture of one or more carbon black material(s) as defined in paragraphs [0039] to [0049], and, optionally, one or more carbon black material(s) as defined in paragraphs [0050] to [0052]. In some embodiments, the weight ratio of the carbon black material(s) as defined in paragraphs [0039] to

[0049] to the carbon black material(s) as defined in paragraphs [0050] to [0052] may range from about 5:95 to about 95:5, or from about 10:90 to about 90:10, or from about 20:80 to about 80:20, or from about 30:70 to about 70:30, or from about 40:60 to about 60:40.

[0054] It will be understood that in all embodiments relating to or mentioning the graphitized/heat- treated carbon black materials described herein, the above compositions comprising a mixture of different carbon black materials will always be encompassed by the term "carbon black materials described herein", unless specifically stated otherwise. [0055] In general, the carbon black materials as described herein may be present as a fine powder (typically in the sub-micrometer size range), or they may be present as agglomerates, e.g., in granulated form, which typically improves handling of the particulate material due to its increased apparent density. In some embodiments, the granules have an average diameter (e.g. expressed as a D₅₀ value) of between about 20 μΜ and up to 5 mm. However, it will be appreciated that the granules are advantageously "soft" granules, which during the compounding process are typically dispersed into the matrix as smaller de-agglomerated particles, i.e. they are essentially no longer present as granules within the polymer matrix, although this will of course depend a bit on the shear forces applied to the granules during the compounding process.

Manufacturing Process for the Graphitized Carbon Black Materials described herein

[0056] The present disclosure in a further aspect relates to a process for making the graphitized carbon black materials described herein. More specifically, the process for producing a carbon black material as disclosed herein comprises subjecting a carbon black starting material in particulate form (e.g., as a powder or in granulated form) for a defined period of time to a temperature of between 1600°C and 3500° in a reactor in the absence of reactive gases. Thus, in some embodiments, the process in the reactor is carried out in an inert atmosphere (such as nitrogen or argon, or mixtures thereof).

[0057] The method leads to a (partial) graphitization of the carbon black starting material, as primarily indicated by an observed increase in the crystallite size L_c. (see, e.g., the data in Table 2 below). The temperature is in some embodiments about 2000°C to 3000°C, or 2500 to 3000°C. Typically the heating cycle includes a ramp up phase (e.g., where the temperature is increased by 10°C per minute, and / or by 5°C per minute) until the desired temperature is achieved, followed by a "holding period" for a certain amount of time, and a subsequent gradual temperature decrease (cooling phase, for example again by 10°C per minute).

[0058] The heating is generally carried out until the desired properties of the obtained carbon black material are obtained. For example, in certain embodiments, the heat treatment is carried out for about 10 minutes to 20 hours, e.g., for 1 to 6 hours, or 1.5 to 4 hours or for 2 to 3 hours. As noted above, during the heat treatment time, an inert gas (for example nitrogen and/or argon) may be supplied to the reactor containing the carbon black material. The treatment may be carried out in a heatable reactor, such as a heating furnace working in batch mode, or a continuous reactor such as a rotating kiln. It will be understood that the exact conditions (temperature, heating rate, etc.) will depend on the chosen starting material, the desired product characteristics and the type of reactor, which can be chosen / adapted by those of skill in the art.

[0059] In some embodiments of this aspect, the carbon black starting material used in this process may be characterized by

i) a crystallographic L_c value of about 1 to about 3 nm; and/or

ii) an oil absorption number (OAN) of less than about 200 ml/1 OOg, or of less than about 150 ml / 10Og, or of less than about 100 ml/1 OOg; and/or

iii) a BET SSA of less than about 70 m²/g, or a BET SSA of less than about 50 m²/g, a BET SSA of less than about 30 m²/g, or a BET SSA of less than about 20 m²/g.

[0060] In an exemplary embodiment of this aspect, the carbon black starting material employed as the starting material in the process may be characterized by an oil absorption number (OAN) of about 30 to about 80 ml/1 OOg, and a BET SSA of about 8 to about 1 1 m²/g. Examples of suitable starting materials for this embodiment include thermal carbon blacks such as Thermax^® N990 or Thermax^® N991 (available from Cancarb, Alberta, Canada).

[0061] In another embodiment, the carbon black starting material may be characterized by an oil absorption number (OAN) of about 100 to 200 ml/1 OOg, and a BET SSA of about 40 to 80 m²/g, or an OAN of 150 to 200 ml/1 OOg, and a BET SSA of 45 to 70 m²/g. An example of a suitable starting material for this embodiment would be Ensaco^® 250G and Ensaco^®150G carbon blacks (available from Imerys Graphite & Carbon, Switzerland), however other carbon black starting materials may be used. [0062] The heat-treated carbon black material may optionally be granulated after the heat-treatment. Additionally or alternatively, it may already be granulated before subjecting it to the heat-treatment. In some examples, the heat-treated carbon black material may not be granulated at all.

[0063] Thus, having regard to the process described above, the present disclosure also relates to heat-treated (i.e. graphitized) carbon black materials in particulate form obtainable by the process described herein. Polymer Composite Materials comprising Graphitized Carbon Black Materials

[0064] Yet another aspect of the present disclosure relates to polymer composite materials comprising a carbon black material in particulate form dispersed within a polymer matrix, wherein the polymer composite material is further characterized by having a thermal conductivity of at least about 0.8 W/m*k, or at least about 0.9 W/m*K, or at least about 1 .0 W/m*K, or at least about 1.1 W/m*K.

[0065] As noted above, certain novel graphitized carbon blacks as described herein can be added in relatively large quantities to a polymer without causing a strong viscosity increase, which yields polymer composites characterized by rather high (through-plane) thermal conductivities of above 0.9 or 1 W/m*K, which is typically not obtainable with untreated carbon blacks (due to their lower practical loading limit).

[0066] As explained above, in some examples, the polymer composite material comprises one, or a mixture of several (such as two, three, four or five) carbon black materials in particulate form as described herein.

[0067] In some embodiments, the carbon black material in particulate form in the polymer composite material is the only additive conveying increased thermal conductivity to the polymer, while in other embodiments, the polymer composite material further comprises at least one further additive conveying increased thermal conductivity to the polymer composite material. Examples of such additives include but are not limited to natural or synthetic graphite, expanded graphite, ground expanded graphite aggregates, surface-modified graphites, carbon nanotubes, carbon fibers, graphene, coke, boron nitride, aluminum oxide, aluminum nitride, a silicate, a modified silicate, magnesium oxide, zinc oxide, talc, and combinations thereof.

[0068] The polymer composite materials comprise in certain embodiments at least about 30 wt%, or at least about 40 wt%, or at least about 50 wt% of said carbon black material. As described in the Example section below, polymer composites comprising 60% of graphitized N990 or N991 grade carbon blacks yielded polypropylene composites having a through plane conductivity of up to 1.2 W/m*K (cf. Fig. 3).

[0069] Alternatively, the graphitized carbon blacks described herein may also be useful as a minor additive, e.g., in amounts of less than 30 wt%, such as about 5 wt% to 25 wt%, or 10 wt% to 20 wt%, for example in polymer composites comprising graphite and/or other additives, in order to increase the thermal conductivity and also, optionally, the mechanical properties of resulting polymer composite material.

[0070] The polymer matrix of the polymer composite materials according to the present disclosure may be a thermoplastic polymer, a thermosetting polymer, or a synthetic or natural rubber. Examples include, but are not limited to polymers such as low density polyethylene, medium density polyethylene, high density polyethylene, polypropylene, or polyamides, polyesters, polycarbonates, polyketones, polystyrenes, polymethylmethacrilate, polyphenylene sulphides, polyphenylene oxides, polysulfones, polyarylates, polyetheretherketones, polyetherimides, thermoplastic elastomers, polylactic acids, polyoxymethylenes, polyvinyl chloride, polybutene, acrylonitrile-butadiene-styrene copolymers, styrene-acrylonitrile copolymers, polytetrafluoroethylene, polyvinylidenefluoride, ethylenetetrafluoroethylene, polyvinylfluoride, urethane based thermoplastic elastomers, ester-ether based thermoplastic elastomers, amide based thermoplastic elastomers, styrene based thermoplastic elastomers, butadiene rubber, chlorinated polyethylene rubber, chloroprene rubber, ethylene- propylene-diene rubber, hydrogenated acrylonitrile-butadiene rubber, acrylonitrile-butadiene rubber, natural rubber, silicone rubber, styrene-butadiene rubber, epoxy resins, melamine-formaldehyde resin, phenol-formaldehyde resin, polyurethanes, urea formaldehyde resin, unsaturated polyester resins, and the like, and any mixture(s) or blend(s) thereof.

[0071] The polymer composite materials comprising the graphitized carbon black materials of the present disclosure are generally characterized by beneficial mechanical properties, such as high impact strength, particularly when compared to polymer composites comprising graphite particles.

[0072] In certain embodiments, the present disclosure relates to a polymer composite material comprising a graphitized carbon black material in particulate form characterized by a crystallite size L_c of above about 3.5 nm, or above about 4 nm, or above about 5 nm dispersed in a polymer matrix, wherein the polymer matrix is not polypropylene.

[0073] The present disclosure also relates to a polymer composite material comprising a graphitized carbon black material in particulate form characterized by a crystallite size L_c of above about 3.5 nm, or above about 4 nm, or above about 5 nm dispersed in a polymer matrix, wherein the graphitized carbon black material in particulate form was not made in an electrothermal fluidized bed furnace.

[0074] In these embodiments, the carbon black material in particulate form incorporated in the polymer matrix may be chosen from carbon blacks as specifically defined herein, or as obtained from the heat-treatment processes described herein. Method for Preparing the Polymer Composite Materials comprising Graphitized Carbon Blacks

[0075] A further aspect of the present disclosure relates to methods for producing the polymer composite materials as described herein. The method may comprise mixing a graphitized carbon black material in particulate form as described herein, e.g., characterized by a crystallite size L_c of above about 3.5 nm, or above about 4 nm, or above about 5 nm with the polymer. In the case of thermoplastic polymers, the polymer is typically heated until it is in molten form (for example, when the polymer is polypropylene, the polymer is heated to a temperature of around 200°C), and then the carbon black particles are added to the molten polymer matrix and mixed homogenously into the matrix in a suitable reactor (compounder). Suitable examples of compounding devices include, but are not limited to twin screw extruders, co-kneading devices, internal mixers, planetary mixers, and single screw extruders. After thorough mixing the polymer composite may be cooled down to obtain the solid polymer composite material. In some examples, the composite material is molded into the desired form in the molten state before it is allowed to cool down and solidify. In the case of rubbers, the carbon black particles (or other additives) are added to the rubber, which is typically softened by mechanical processing and heating. Suitable devices for processing rubbers include double roll mills, internal mixers, and twin screw extruders. Once the rubber compound is thoroughly mixed with the additives, it may be processed in the final form (molded or extruded) and cured, such as by heating. For thermosets, the additives like the carbon blacks described herein and/or other graphitic materials are typically added to the resin which is often in liquid form. The resin can be heated to increase fluidity or to convert it from a solid state into a liquid state. In two-component systems, the curing agent is then added and the material is heated to allow crosslinking and/or to speed up the curing process. In other thermosets the cure can be trigged by other means like exposure to moisture or radiation. Alternatively, in two component systems, the additives may be added to the curing agent before mixing with the resin.

[0076] Having regard to the unique properties of the graphitized carbon black materials described herein, another aspect of the present disclosure relates to the use of a carbon black material as disclosed herein for producing a polymer composite material having a relatively high thermal conductivity, such as a (through-plane) thermal conductivity of at least about 0.8, or at least 0.9, or at least 1.0, or at least 1 .1 W/m*K, or at least 1 .2 W/m*K.

[0077] Alternatively, the graphitized carbon black material as disclosed herein may be used for increasing the thermal conductivity of a polymer composite material, which may optionally comprise further additives conveying thermal conductivity to the polymer. [0078] Thus, in a related aspect, the present disclosure further relates to the use of a carbon black material in particulate form characterized by a BET SSA of less than about 75 m²/g, a crystallite size L_c of above about 4.0 nm, or above about 4.5 nm, or above about 5 nm, and, optionally, an OAN of below about 220 mL/100g, or below about 220 ml_/100g (such as certain graphitized carbon blacks as described herein) for preparing a polymer composite material having a through-plane thermal conductivity of at least about 1 W/m*K, or at least about 1.5 W/m*K, or at least about 2 W/m*K, or at least about 3 W/m*K. In particular for polymer composites having a through-plane thermal conductivity of more than about 1 .3 or 1 .5 W/m*K, the polymer composite material may further comprise synthetic or natural graphite particles (including surface-modified graphites, expanded graphite, ground expanded graphite agglomerates, and the like), or other thermal conductivity- enhancing additives such as those described above. In some embodiments of this aspect, the polymer composite material may comprise between 5 and 70 wt% of said graphitic particles besides the graphitized carbon black particles described herein.

[0079] The disclosure also provides in another aspect the use of a carbon black material as described herein for producing a polymer composite material having a high carbon black loading. For example, in some embodiments, the low structure graphitized carbon blacks as described in certain embodiments, can be used to produce polymer composite materials, such as thermoplastic polymer composites, comprising at least about 35 wt%, or at least about 40 wt%, or at least about 45 wt%, or at least about 50 wt%, or at least about 55 wt%, or at least about 60 wt% of said carbon black material.

[0080] The use of a carbon black material as defined herein as an additive for a polymer material thus represents another aspect of the present disclosure. Such polymer composite materials or products comprising such polymer composite materials may be selected from, but are not limited to: materials for handling of electronic components such as carrier boxes, carrier trays, carrier tapes; films such as antistatic and conductive films, packaging films, garbage bags; materials used in the automotive industry such as fuel injection systems, anticorrosion systems, fuel tank inlets, electrostatically paintable parts; transport materials such as mobile phone parts, wheels, containers, bins, pallets; computer-related materials such as antistatic articles for computer & accessories, CD player; materials used in medical applications or in cleanroom equipments; articles for antistatic workplaces; antistatic flooring materials; heating elements, heat-sinks, sensors, PTC switches, tire curing bladder, geothermal pipes, LED light sockets, heat exchangers, appliance temperature sensors, gaskets, vibration dampening or interface materials; bipolar plates (for fuel cells), brake pads, carbon brushes, or polymer materials with increased UV protection and pigmentation. Accordingly, the above polymer composite materials or products comprising said polymer composite materials represent another aspect of the present disclosure.

[0081] Finally, correlations between the characteristics of the carbon black and the resulting thermal conductivity of the polymer composites comprising the carbon black as an additive were observed, which can be used in predicting/calculating the resulting conductivity of a polymer composite at a given loading concentration, or in determining the loading concentration of the carbon black to produce a composite material having a desired thermal conductivity.

[0082] Accordingly, in another aspect, the present disclosure also provides a method of predicting the thermal conductivity k of a polymer composite material comprising a carbon black material in particulate form dispersed, in some embodiments homogenously dispersed, in a polymer matrix, the method comprising determining the OAN, the crystallographic L_c value and the loading concentration of the carbon black material in the polymer composite material, and calculating the thermal conductivity according to the formula k = A + B*OAN*L_c*loading concentration², wherein A is the thermal conductivity of the polymer without additive, and B is the slope of the straight line when plotting the thermal conductivity versus the value (OAN*L_c*loading concentration²).

[0083] Furthermore, the disclosure provides a method of preparing a polymer composite material comprising a carbon black material in particulate form dispersed (which can include homogenously dispersed) in a polymer matrix having a desired thermal conductivity k, wherein the method comprises selecting a carbon black material having an OAN and an Lc value, choosing the loading concentration of the carbon black material in the polymer composite according to the formula k = A + B*

OAN*L_c*(loading concentration)², and mixing the chosen loading concentration of the carbon black material with the polymer matrix. The desired thermal conductivity may be high, medium or low, as desired. [0084] The disclosure may be further illustrated by the following non-limiting numbered

embodiments:

1. A carbon black material in particulate form, characterized by a crystallite size L_c of greater than about 8 nm, or greater than about 10 nm, or greater than about 1 1 nm, or greater than about 12 nm, and wherein the material is further characterized by

2. The carbon black material according to embodiment 1 , characterized by a xylene density of more than 1.90 g/cm³, or more than 1 .93 g/cm³, or more than 1.95 g/cm³, or more than 1.98 g/cm³, or more than 2.00 g/cm³, optionally wherein the xylene density of the material is about 1.90 g/cm³ to about 2.20 g/cm³, or about 1.95 g/cm³ to about 2.20 g/cm³, or about 2.00 g/cm³ to about 2.20 g/cm³.

3. The carbon black material according to embodiment 1 or embodiment 2, further characterized by an interlayer distance c/2 of between about 0.3370 nm and about 0.3500 nm, or between about 0.3380 nm and about 0.3450 nm, or between about 0.3380 nm and about 0.3430 nm, or between 0.3390 to 0.3420 nm.

4. The carbon black material according to any one of embodiments 1 to 3, further characterized by a pressed density (determined at a pressure of 20 kN/cm²) of more than about 1.40 g/cm³, or more than about 1.45 g/cm³, or more than about 1.50 g/cm³.

5. The carbon black material according to any one of embodiments 1 to 4, further characterized by a minimum void volume at a pressure of 20 kN/cm² of less than about 19%, or less than about 17%, or less than about 15%, or less than about 13%, or less than about 12%.

6. The carbon black material according to any one of embodiments 1 to 5, further characterized by

i) a sulfur content of less than about 100 ppm, or less than about 50 ppm, or less than about 30 ppm; and/or

ii) a polycyclic aromatic hydrocarbon (PAH) content of less than about 1000 ppm, or less than about 800 ppm, or less than about 600 ppm, or less than about 400 ppm, or less than about 200 ppm or less than about 100 ppm.

7. The carbon black material according to any one of embodiments 1 to 6, further characterized by a crystallite size L_c of less than about 30 nm, or less than about 25 nm, or less than about 20 nm. The carbon black material according to any one of embodiments 1 to 7, further characterized by a loading limit in polypropylene of at least 45 wt%, or at least 50 wt%, or at least 55 wt%, wherein the loading limit is defined as the weight content at which the torque level, measured at a temperature of 200°, is larger than 8 Nm, or larger than 9 Nm, or larger than 10 Nm. A carbon black material in particulate form, characterized by a crystallite size L_c of about 3.5 nm to about 7.5 nm, or about 4.5 nm to 6.5 nm, wherein the material is further characterized by

i) an oil absorption (OAN) of about 100 ml/100g to 250 ml/100 g. or of about 150 ml/100g to 220 ml/100 g; and/or

ii) a BET SSA of about 40 to 75 m²/g, or of about 50 to 65 m²/g. The carbon black material of any one of embodiments 1 to 9, wherein the particles are in agglomerated form as granules, wherein the granules have an average diameter of between about 20 μΜ to 5 mm. A composition comprising a mixture of one or more carbon black materials as defined in any one of embodiments 1 to 8 and one or more carbon black materials as defined in embodiment 9 or 10; optionally wherein the ratio of the carbon black material as defined in any one of embodiments 1 to 8 to the carbon black material as defined in embodiments 9 and 10 ranges from 5:95 to 95:5, or from 10:90 to 90:10, or from 30:70 to 70:30, or from 40:60 to 60:40. A process for producing a carbon black material as defined in any one of embodiments 1 to 10, comprising subjecting a carbon black starting material in particulate form to a temperature of between 1600°C and 3500° in the absence of reactive gases in a reactor, optionally wherein the thermal treatment is carried out in a reactor in an inert atmosphere. The process according to embodiment 12, wherein the carbon black starting material is characterized by

i) a crystallographic L_c value of about 1 to about 3 nm; and/or

ii) an oil absorption number (OAN) of less than about 200 ml/100g; and/or

iii) a BET SSA of less than about 70 m²/g. The process according to any one of embodiments 12 or 13, wherein the carbon black starting material is characterized by an oil absorption number of about 30 to 80 ml/100g, and a BET SSA of about 8 to 1 1 m²/g, to obtain a carbon black material as defined in any one of embodiments 1 to 8. The process according to any one of embodiments 12 or 13, wherein the carbon black starting material is characterized by an oil absorption number of about 100 to 200 ml/1 OOg, and a BET SSA of about 40 to 80 m²/g, to obtain a carbon black material as defined in embodiment 10. Carbon black material obtainable by the process according to any one of embodiments 12 to 15.

A polymer composite material, wherein a carbon black material in particulate form is dispersed in a polymer matrix, wherein the polymer composite material is further

characterized by having a thermal conductivity of at least about 0.8 W/m*k, or at least about 0.9 W/m*k, or at least about 1 .0 W/m*k, or at least about 1 .1 W/m*k.

The polymer composite material according to embodiment 17, wherein the carbon black material in particulate form is a carbon black material as defined in any one of embodiments 1 to 8 or 16, or a composition according to embodiment 1 1.

The polymer composite material according to embodiment 17 or embodiment 18, wherein the carbon black material in particulate form is the only additive conveying increased thermal conductivity to the polymer.

The polymer composite material according to embodiment 17 or embodiment 18, further comprising at least one further additive conveying increased thermal conductivity to the polymer composite material, optionally wherein the further additive is selected from natural or synthetic graphite, expanded graphite, coke, carbon nanotubes, carbon fibers, graphene, boron nitride, aluminum oxide, aluminum nitride, a silicate, a modified silicate, magnesium oxide, zinc oxide, talc, or combinations thereof.

The polymer composite material according to any one of embodiments 17 to 20, comprising at least about 30 wt%, or at least about 40 wt%, or at least about 50 wt% of said carbon black material.

The polymer composite material according to any one of embodiments 17 to 21 , wherein the polymer matrix is selected from the group consisting of a thermoplastic polymer, a thermosetting polymer, or a synthetic or natural rubber; optionally wherein the polymer matrix is selected from the group consisting of polyolefine based thermoplastic elastomers such as low density polyethylene, high density polyethylene, or polypropylene, polyamides, polyesters, polycarbonates, polyketones, polystyrenes, polymethylmethacrilate, polyphenylene sulphides, polyphenylene oxides, polysulfones, polyarylates, polyetheretherketones, polyetherimides, thermoplastic elastomers, polylactic acids, polyoxymethylenes, polyvinyl chloride, polybutene, acrylonitrile-butadiene-styrene copolymers, styrene-acrylonitrile copolymers,

polytetrafluoroethylene, polyvinylidenefluoride, ethylenetetrafluoroethylene, polyvinylfluoride, urethane based thermoplastic elastomers, ester-ether based thermoplastic elastomers, amide based thermoplastic elastomers, styrene based thermoplastic elastomers, butadiene rubber, chlorinated polyethylene rubber, chloroprene rubber, ethylene-propylene-diene rubber, hydrogenated acrylonitrile-butadiene rubber, acrylonitrile-butadiene rubber, natural rubber, silicone rubber, styrene-butadiene rubber, epoxy resins, melamine-formaldehyde resin, phenol-formaldehyde resin, polyurethanes, urea formaldehyde resin, unsaturated polyester resins, and any mixture or blend thereof.

A polymer composite material, comprising a graphitized carbon black material in particulate form characterized by a crystallite size L_c of above about 3.5 nm, or above about 4 nm, or above about 5 nm dispersed in a polymer matrix, wherein the polymer matrix is not polypropylene;

optionally wherein the carbon black material in particulate form is as defined in any one of embodiments 1 to 10, or 16, or is a composition as defined in embodiment 1 1.

A polymer composite material comprising a graphitized carbon black material in particulate form characterized by a crystallite size L_c of above about 3.5 nm, or above about 4 nm, or above about 5 nm dispersed in a polymer matrix, wherein the graphitized carbon black material in particulate form was not made in an electrothermal fluidized bed furnace;

A method for producing the polymer composite material according to any one of embodiments 16 to 23, comprising mixing a graphitized carbon black material in particulate form characterized by a crystallite size L_c of above about 3.5 nm, or above about 4 nm, or above about 5 nm with a thermoplastic polymer in molten form, optionally wherein the carbon black material is a carbon black material according to any one of embodiments 1 to 10, or 16, or is a composition as defined in embodiment 1 1.

Use of a carbon black material as defined in any one of embodiments 1 to 10, or 16, or of a composition as defined in embodiment 1 1 to produce a polymer composite material having a high thermal conductivity or to increase the thermal conductivity of a polymer composite material,

optionally wherein the thermal conductivity is at least about 0.8 W/m*k, or at least about 0.9 W/m*k, or at least about 1 .0 W/m*k, or at least about 1 .1 W/m*k.

Use of a carbon black material as defined in any one of embodiments 1 to 9, or 16, or of a composition as defined in embodiment 1 1 to produce a polymer composite material having a high carbon black loading,

optionally wherein the polymer composite material comprises at least about 35 wt%, or at least about 40 wt%, or at least about 45 wt%, or at least about 50 wt% of said carbon black material.

Use of a carbon black material in particulate form characterized by a BET SSA of less than about 75 m²/g, a crystallite size L_c of above about 4.0 nm, or above about 4.5 nm, or above about 5 nm, and, optionally, an OAN of below about 220 mL/100g, or below about 220 ml_/100g for preparing a polymer composite material having a through-plane thermal conductivity of at least about 1 W/m*K, or at least about 1 .3 W/m*K, or at least about 1 .5 W/m*K, or at least about 2 W/m*K, or at least about 3 W/m*K;

optionally wherein the carbon black material in particulate form is as defined in any one of embodiments 1 to 10, or 16, or is a composition as defined in embodiment 1 1 . 29. The use of embodiment 28, wherein the polymer composite material further comprises

graphitic particles; optionally wherein the polymer composite material comprises between 5 and 70 wt% of said graphitic particles.

30. The use of embodiment 29, wherein the graphitic particles are selected from synthetic

graphite, natural graphite, expanded graphite, ground expanded graphite aggregates, surface- modified graphites, carbon nanotubes, and graphene.

31 . Use of a carbon black material as defined in any one of embodiments 1 to 10, or 16, or of a composition as defined in embodiment 1 1 as an additive for a polymer material,

optionally wherein the polymer materials are selected from:

materials for handling of electronic components such as carrier boxes, carrier trays, carrier tapes;

films such as antistatic and conductive films, packaging films, garbage bags;

materials used in the automotive industry such as fuel injection systems, anticorrosion systems, fuel tank inlets, electrostatically paintable parts;

transport materials such as mobile phone parts, wheels, containers, bins, pallets;

computer-related materials such as antistatic articles for computer & accessories, CD player; materials used in medical applications or in cleanroom equipments;

articles for antistatic workplaces;

antistatic flooring materials;

heating elements, heat-sinks, sensors, PTC switches, tire curing bladder, geothermal pipes, LED light sockets, heat exchangers, appliance temperature sensors, gaskets, vibration dampening or interface materials;

bipolar plates (for fuel cells), brake pads, carbon brushes;

or polymer materials with increased UV protection and pigmentation.

32. A polymer composite material selected from:

films such as antistatic and conductive films, packaging films, garbage bags;

articles for antistatic workplaces; antistatic flooring materials;

heating elements, heat-sinks, heat exchangers, sensors, PTC switches, tire curing bladder, geothermal pipes, LED light sockets, appliance temperature sensors, gaskets, vibration dampening or interface materials;

bipolar plates (for fuel cells), brake pads, carbon brushes;

or polymer materials with increased UV protection and pigmentation

comprising a carbon black material as defined in any one of embodiments 1 to 10, or 16, or a composition as defined in embodiment 1 1.

33. A method of predicting the thermal conductivity k of a polymer composite material comprising a carbon black material in particulate form dispersed in a polymer matrix, the method comprising determining the OAN, the crystallographic L_c value and the loading concentration of the carbon black material in the polymer composite material, and calculating the thermal conductivity according to the formula k = A + B*OAN*L_c*(loading concentration)², wherein A is the thermal conductivity of the polymer without additive, and B is the slope of the straight line when plotting the thermal conductivity versus the value (OAN*L_c*(loading concentration)²).

34. A method of preparing a polymer composite material comprising a carbon black material in particulate form dispersed in a polymer matrix and having a desired thermal conductivity k, the method comprising selecting a carbon black material having an OAN and an L_c value, choosing the loading concentration of the carbon black material in the polymer composite according to the formula k = A + B* OAN*L_c*(loading concentration)², and mixing the chosen loading concentration of the carbon black material with the polymer matrix.

MATERIALS AND METHODS

X-Rav Diffraction

[0085] XRD data were collected using a PANalytical X'Pert PRO diffractometer coupled with a PANalytical X'Celerator detector. The diffractometer has following characteristics shown in Table 1 :

Table 1 : Instrument data and measurement parameters:

[0086] The data were analyzed using the PANalytical X'Pert HighScore Plus software. Interlayer Spacing c/2

[0087] The interlayer space c/2 was determined by X-ray diffractometry. The angular position of the peak maximum of the [002] reflection profiles were determined and, by applying the Bragg equation, the interlayer spacing was calculated (Klug and Alexander, X-ray diffraction Procedures, John Wiley & Sons Inc., New York, London (1967)). To avoid problems due to the low absorption coefficient of carbon, the instrument alignment and non-planarity of the sample, an internal standard, silicon powder, was added to the sample and the graphite peak position was recalculated on the basis of the position of the silicon peak. The graphite sample was mixed with the silicon standard powder by adding a mixture of polyglycol and ethanol. The obtained slurry was subsequently applied on a glass plate by meaning of a blade with 150 pm spacing and dried.

Crystallite Size L

[0088] Crystallite size was determined by analysis of the [002] diffraction profile and determining the widths of the peak profiles at the half maximum. The broadening of the peak should be affected by crystallite size as proposed by Scherrer (P. Scherrer, Gottinger Nachrichten 2, 98 (1918)). However, the broadening is also affected by other factors such X-ray absorption, Lorentz polarization and the atomic scattering factor. Several methods have been proposed to take into account these effects by using an internal silicon standard and applying a correction function to the Scherrer equation. For the present disclosure, the method suggested by Iwashita (N. Iwashita, C. Rae Park, H. Fujimoto, M. Shiraishi and M. Inagaki, Carbon 42, 701 -714 (2004)) was used. The sample preparation was the same as for the c/2 determination described above.

For the present disclosure, the method described in ASTM D5187-10 for calcined petroleum cokes was adapted for the carbon black materials described herein.

Reference: ASTM D5187-10 Specific BET Surface Area (BET SSA)

[0089] The measurements were carried out on a gas adsorption analyzer. The method is based on the registration of the adsorption isotherm of liquid nitrogen in the range p/p0=0.01 -0.30, at 77 K. Following the procedure proposed by Brunauer, Emmet and Teller (Adsorption of Gases in

Multimolecular Layers, J. Am. Chem. Soc, 1938, 60, 309-319), the monolayer capacity can be determined. On the basis of the cross-sectional area of the nitrogen molecule, the monolayer capacity and the weight of sample, the specific surface area was then calculated.

Reference: ASTM D6556-14

Oil Absorption Number

[0090] Paraffin oil was added by means of a constant-rate burette to a dried (1 h at 125 °C) carbon black sample in the mixer chamber of the absorptometer. As the sample absorbs the oil, the mixture changes from a free-flowing state to one of a semi-plastic agglomeration, with an accompanying increase in viscosity. This increased viscosity is transmitted to the torque- sensing system. When the viscosity reaches a predetermined torque level, the absorptometer and burette will shut off simultaneously. The volume of the added oil is read from the burette. The volume of oil per unit mass of carbon black is the oil absorption number.

[0091 ] For the carbon black materials described herein, the OAN value was measured according to ASTM D2414-14, procedure A (end-Point at fixed torque level 400 mN.m) or procedure B (end-point at 70 % of the maximum torque) with the following parameters: paraffin oil, 10 g carbon black.

Reference: ASTM D2414-14

Xylene Density

[0092] The analysis is based on the principle of liquid exclusion as defined in DIN 51 901 . Approx. 2.5 g (accuracy 0.1 mg) of powder is weighed in a 25 ml pycnometer. Xylene is added under vacuum (15 Torr). After a few hours dwell time under normal pressure, the pycnometer is conditioned and weighed. The density represents the ratio of mass and volume. The mass is given by the weight of the sample and the volume is calculated from the difference in weight of the xylene filled pycnometer with and without sample powder.

Reference: DIN 51 901

Pressed Density and (Minimum) Void Volume

[0093] About 0.5 g of a carbon black sample were compressed inside a die (a cylinder block made of steel having an inner diameter of 1 1 .3 mm) between two pistons (made of brass). The applied force was measured using a load cell and was controlled versus time during the experiment ("load control", as opposed to "displacement control"), while the relative position of the pistons in the die (i.e. the "height" of the compressed carbon black in the cylinder) was measured using a length gauge.

Pressure [kN/cm²] was calculated from the applied force and the cross-sectional area of the cylinder (and pistons). In the present case, the pressed density determined at 20 kN/cm² was calculated from the mass of the weighed carbon black sample, the cross-sectional area of the cylinder, and the "height" of the compressed carbon black in the cylinder at a pressure of 20 kN/cm².

[0094] The minimum void volume [in %] at a pressure of 20 kN/cm² was calculated with the following relationship: (1 - pressed density at 20 kN/cm² / real density (xylene density) of the carbon black)*100. Reference: ASTM D 6086 Polvcvclic Aromatic Hydrocarbon (PAH) Concentration

[0095] The concentration of polycyclic aromatic hydrocarbons (PAHs) was determined by the Grimmer method and the analyses were performed externally by BIU-Grimmer (Germany). The Grimmer method generally used for PAH analysis is based on a stable isotope dilution methodology using GC-MS(SIM) for quantification in the sub ppb range. Sulfur Content

[0096] The total sulfur content was analyzed by inserting a sample (ca 0.2 - 0.5 g) in a combustion furnace and burning the sample at 1350 °C in a stream of oxygen to oxidize the sulfur. The sulfur dioxide content is then measured by IR spectroscopy. At least three samples were analyzed and the sulfur content was taken as the average. For a calibration check the Leco Standard 502-852 was used.

Reference: ASTM D1619 Viscosity

[0097] The viscosity of the compound in the molten state has been estimated by the torque values automatically generated by an internal mixer (Haake Polylab OS equipped with Rheomix 610) with constant chamber and rotor design by adding a constant volume of the plastic material to be evaluated at a chamber temperature at which the polymer is molten.

Thermal Conductivity Tests of Polymer Composite Materials

[0098] Thermal conductivity tests of polymer compounds were performed at 25°C using a Netzsch Laserflash LFA 447. The compound in the form of a compression molded 2mm thick plaque has been cut in the form of a 25.6mm disk to be placed inside the instrument. The density of the material was measured by a density determination KIT for AG204 Mettler balance based on water immersion. After the determination of the density, the sample was coated with a carbonaceous conductive layer two times, each time after being dried. The thickness of the sample was measured by measuring the thickness at six different places of the disk and then calculating the average value. The sample was inserted in the sample holder and the measurement is taken with a Netzsch Laserflash LFA447 at 25°C, controlling the temperature by a refrigerating/ heating regulator (Julabo F32). After the measurement is recorded, software "Cowan plus pulse correction" procedure is used to fit the detector signal and calculate the diffusivity. An internal reference was used to calculate the heat capacity according to the procedure present in the Laserflash LFA447 manual and ASTM E 1461 . The reference sample is measured the same day and at the same temperature of the sample

measurement. The thermal conductivity is automatically measured by the software by multiplying the diffusivity by the average density and by the heat capacity of the materials.

Reference: ASTM E 1461. [0099] The following working examples are intended to further illustrate certain embodiments of the present disclosure, but not to limit them. EXAMPLES

EXAMPLE 1

Preparation of Graphitized Carbon Blacks

[0100] An exemplary process for the preparation of the carbon black materials described herein is discussed below. The process comprises a thermal treatment process, e.g., a post-treatment of a carbon black starting material in an inert atmosphere, e.g., in the absence of reactive, oxygen- containing gases. Apart from leading to an increase in the crystallite size L_c through the partial graphitization of the carbon black material, this heat treatment was observed to also lead to a (slight) decrease of the specific surface area. Besides the choice of the starting material, the control of the thermal process parameters was found to provide carbon materials having the desired crystallite size L_c and OANs as defined herein.

[0101] For example, the treatment time and temperature employed may be varied to provide the desired properties. In general, the carbon to be treated may be heated to a temperature in the range from 1600°C to 3500°C, and held at that temperature for a time e.g. ranging from 10 minutes to 20 hours though it will be appreciated that the exact conditions depend on the carbon black source and the reactor employed for the generation of the carbon black material. Prior to and/or during the heat treatment, an inert gas (for example nitrogen and/or argon) may be supplied to the reactor with the carbon material. The treatment may be conveniently carried out in a heatable reactor. It may for example be a heating furnace working in batch mode or a continuous reactor such as a rotating kiln. Preparation of graphitized Carbon Black E150G

Starting material: Carbon Black E150G

Process conditions:

200 g of the CB material E150G was filled in a graphite crucible and loaded in a graphitization furnace (XGRAFT by Xerion). Under argon flow (2 L/min) the material was heated to 3000°C with a heating ramp of 10°C/min up to 2000°C and 5°C/min up to 3000°C, and thereafter held at 3000°C for 2 h. Cooling was carried out at the same rate as heating.

Preparation of graphitized Carbon Black E250G

Starting material: Carbon Black E250G

Process conditions:

309 g of the CB material E250G was filled in a graphite crucible and loaded in a graphitization furnace (XGRAFT by Xerion). Under argon flow (2 L/min) the material was heated to 3000°C with a heating ramp of 10°C/min up to 2000°C and 5°C/min up to 3000°C, and thereafter held at 3000°C for 2 h. Cooling was carried out at the same rate as heating. Preparation of graphitized Carbon Black N990

Starting material: Carbon Black N990 Process conditions:

397 g of the CB material N990 was filled in a graphite crucible and loaded in a graphitization furnace (XGRAFT by Xerion). Under argon flow (2 L/min) the material was heated to 2500^DC with a heating ramp of 10°C/min up to 2000°C and 5°C/min up to 2500°C, and thereafter held at 2500°C for 2 h. Cooling was carried out at the same rate as heating.

Preparation of graphitized Carbon Black N991

Starting material: Carbon Black N991 Process conditions:

248 g of the CB material N991 was filled in a graphite crucible and loaded in a graphitization furnace (XGRAFT by Xerion). Under argon flow (2 L/min) the material was heated to 2500^DC with a heating ramp of 10°C/min up to 2000°C and 5°C/min up to 2500°C, and thereafter held at 2500°C for 2 h. Cooling was at the same rate as heating. Table 2: Characteristics of Carbon Black Starting Material and Heat-treated (Graphitized) Carbon Black materials according to Procedure described above (% values for CB content are % by weight)

EXAMPLE 2

Preparation of Polymer Composite Material

[0102] Polypropylene Moplen HP501 L was used as the polymeric matrix. A Haake Polylab OS equipped with internal mixer unit Rheomix 600 was used to mix the polymer and the carbon black. During all the experiments the filling rate of the chamber (polymer and carbon black) was fixed at 80% of the internal mixer free volume available. The internal mixer temperature was set at 200°C and the polymer was added and melted in the internal mixer for two minutes at 100 rpm. Without stopping the rotors of the internal mixer, the carbon black was then added to the molten polymer and mixed at the same speed (100 rpm) for five more minutes at the desired concentration (typically 10, 20, 30 or 60 % by weight, respectively). As shown in Fig. 6, the viscosity increased significantly for the higher structured carbon blacks such as E250G above a loading concentration above about 30 wt%, thereby preventing homogenous distribution within the polymer matrix at such higher loadings.

[0103] The polymer composite material was then taken out from the chamber and compression molded in a 60x60x2mm (width, length, thickness) at 200°C (plaque temperature) with 2 min of preheating time while the pressure was applied for five minutes. The pressure was applied progressively to a value between 25 and 80 MPa. The sample was then cooled down to room temperature with water refrigerated cooling plates. A disk shaped specimen of 25.6 mm diameter was cut out (CNC machine with a cutting tool running at 10000 rpm) and subsequently used for characterization. The results of the through-plane thermal conductivity at different loading concentrations are shown in Table 3 below (see also Figs. 1 to 5).

Table 3: Through-plane thermal conductivity at different loading concentrations of carbon black materials in polypropylene

* Not possible to homogenously disperse CB into the polymer matrix due to too high viscosity during compounding, see also data shown in Fig. 6.

Claims

A carbon black material in particulate form, characterized by a crystallite size L_c of greater than about 8 nm, or greater than about 10 nm, or greater than about 1 1 nm, or greater than about 12 nm, and wherein the material is further characterized by

The carbon black material according to claim 1 , further characterized by

a) a xylene density of more than 1.90 g/cm³, or more than 1.93 g/cm³, or more than 1.95 g/cm³, or more than 1 .98 g/cm³, or more than 2.00 g/cm³, optionally wherein the xylene density of the material is about 1.90 g/cm³ to about 2.20 g/cm³, or about 1.95 g/cm³ to about 2.20 g/cm³, or about 2.00 g/cm³ to about 2.20 g/cm³;

b) an interlayer distance c/2 of between about 0.3370 nm and about 0.3500 nm, or between about 0.3380 nm and about 0.3450 nm, or between about 0.3380 nm and about 0.3430 nm, or between 0.3390 to 0.3420 nm;

c) a pressed density (determined at a pressure of 20 kN/cm²) of more than about 1.40 g/cm³, or more than about 1.45 g/cm³, or more than about 1.50 g/cm³;

d) a minimum void volume at a pressure of 20 kN/cm² of less than about 19%, or less than about 17%, or less than about 15%, or less than about 13%, or less than about 12%; e) a sulfur content of less than about 100 ppm, or less than about 50 ppm, or less than about 30 ppm;

f) a polycyclic aromatic hydrocarbon (PAH) content of less than about 1000 ppm, or less than about 800 ppm, or less than about 600 ppm, or less than about 400 ppm, or less than about 200 ppm or less than about 100 ppm; and/or

g) a crystallite size L_c of less than about 30 nm, or less than about 25 nm, or less than about 20 nm.

The carbon black material according to claim 1 or claim 2, further characterized by a loading limit in polypropylene of at least 45 wt%, or at least 50 wt%, or at least 55 wt%, wherein the loading limit is defined as the weight content at which the torque level, measured at a temperature of 200°, is larger than 8 Nm, or larger than 9 Nm, or larger than 10 Nm.

A carbon black material in particulate form, characterized by a crystallite size L_c of about 3.5 nm to about 7.5 nm, or about 4.5 nm to 6.5 nm, wherein the material is further characterized by

i) an oil absorption (OAN) of about 100 ml/1 OOg to 250 ml/100 g. or of about 150 ml/100g to 220 ml/100 g; and/or

Ii) a BET SSA of about 40 to 75 m²/g, or of about 50 to 65 m²/g.

The carbon black material of any one of claims 1 to 4, wherein the particles are in agglomerated form as granules, wherein the granules have an average diameter of between about 20 μΜ to about 5 mm.

A process for producing a carbon black material as defined in any one of claims 1 to 5, comprising subjecting a carbon black starting material in particulate form to a temperature of between 1600°C and 3500° in the absence of reactive gases in a reactor, optionally wherein the thermal treatment is carried out in a reactor in an inert atmosphere;

optionally wherein the carbon black starting material is characterized by

i) a crystallographic L_c value of about 1 to about 3 nm; and/or

ii) an oil absorption number (OAN) of less than about 200 ml/100g; and/or

iii) a BET SSA of less than about 70 m²/g.

The process according to claim 6, wherein the carbon black starting material is characterized by

i) an oil absorption number of about 30 to 80 ml/100g, and a BET SSA of about 8 to 1 1 m²/g, to obtain a carbon black material as defined in any one of claims 1 to 3; or

ii) an oil absorption number of about 100 to 200 ml/1 OOg, and a BET SSA of about 40 to 80 m²/g, to obtain a carbon black material as defined in claim 4.

Carbon black material obtainable by the process according to claim 6 or claim 7.

A composition comprising a mixture of one or more carbon black materials as defined in any one of claims 1 to 3 and one or more carbon black materials as defined in claim 4;

optionally wherein the ratio of the carbon black material as defined in any one of claims 1 to 3 to the carbon black material as defined in claim 4 ranges from 5:95 to 95:5, or from 10:90 to 90: 10, or from 30:70 to 70:30, or from 40:60 to 60:40.

A polymer composite material, wherein a carbon black material in particulate form is dispersed in a polymer matrix, wherein the polymer composite material is further characterized by having a thermal conductivity of at least about 0.8 W/m*k, or at least about 0.9 W/m*k, or at least about 1 .0 W/m*k, or at least about 1 .1 W/m*k;

optionally wherein

i) the carbon black material in particulate form is a carbon black material as defined in any one of claims 1 to 5 or 8, or a composition as defined in claim 9; and/or

ii) the polymer composite material comprises at least about 30 wt%, or at least about 40 wt%, or at least about 50 wt% of said carbon black material.

The polymer composite material according to claim 10, wherein

the carbon black material in particulate form is the only additive conveying increased thermal conductivity to the polymer; or

the polymer composite material according to claim 10, wherein said polymer composite material further comprises at least one further additive conveying increased thermal conductivity to the polymer composite material,

optionally wherein the further additive is selected from natural or synthetic graphite, expanded graphite, carbon nanotubes, carbon fibers, graphene, coke, boron nitride, aluminum oxide, aluminum nitride, a silicate, a modified silicate, magnesium oxide, zinc oxide, talc, or combinations thereof.

The polymer composite material according to claim 10 or claim 1 1 , wherein the polymer matrix is a thermoplastic polymer, a thermosetting polymer, or a synthetic or natural rubber, optionally wherein the polymer matrix is selected from the group consisting of polyolefin based thermoplastic elastomers such as low density polyethylene, high density polyethylene, or polypropylene, polyamides, polyesters, polycarbonate, polyketones, polystyrene,

polymethylmethacrilate, polyphenylene sulphides, polyphenylene oxides, polysulfones, polyarylates, polyetheretherketones, polyetherimides, thermoplastic elastomers, polylactic acids, polyoxymethylenes, polyvinyl chloride, polybutene, acrylonitrile-butadiene-styrene copolymers, styrene-acrylonitrile copolymers, polytetrafluoroethylene, polyvinylidenefluoride, ethylenetetrafluoroethylene, polyvinylfluoride, urethane based thermoplastic elastomers, ester-ether based thermoplastic elastomers, amide based thermoplastic elastomers, styrene based thermoplastic elastomers, butadiene rubber, chlorinated polyethylene rubber, chloroprene rubber, ethylene-propylene-diene rubber, hydrogenated acrylonitrile-butadiene rubber, acrylonitrile-butadiene rubber, natural rubber, silicone rubber, styrene-butadiene rubber, epoxy resins, melamine-formaldehyde resin, phenol-formaldehyde resin,

polyurethane, urea formaldehyde resin, unsaturated polyester resins, and any mixture or blend thereof.

A polymer composite material, comprising a graphitized carbon black material in particulate form characterized by a crystallite size L_c of above about 3.5 nm, or above about 4 nm, or above about 5 nm dispersed in a polymer matrix, wherein

i) the polymer matrix is not polypropylene; or

ii) the graphitized carbon black material in particulate form was not made in an electrothermal fluidized bed furnace;

optionally wherein the carbon black material in particulate form is as defined in any one of claims 1 to 5, or 8, or is a composition as defined in claim 9.

Use of a carbon black material as defined in any one of claims 1 to 5, or 8, or of the composition of claim 9, to produce a polymer composite material

i) having a high thermal conductivity or to increase the thermal conductivity of a polymer composite material, optionally wherein the thermal conductivity is at least about 0.8 W/m*k, or at least about 0.9 W/m*k, or at least about 1.0 W/m*k, or at least about 1.1 W/m*k; or ii) having a high carbon black loading, optionally wherein the polymer composite material comprises at least about 35 wt%, or at least about 40 wt%, or at least about 45 wt%, or at least about 50 wt% of said carbon black material.

A polymer composite material selected from:

films such as antistatic and conductive films, packaging films, garbage bags;

articles for antistatic workplaces;

antistatic flooring materials;

bipolar plates (for fuel cells), brake pads, carbon brushes;

or polymer materials with increased UV protection and pigmentation

comprising a carbon black material as defined in any one of claims 1 to 5, or 8, or a composition as defined in claim 9.

A method of predicting the thermal conductivity k of a polymer composite material comprising a carbon black material in particulate form dispersed in a polymer matrix, the method comprising determining the OAN, the crystallographic L_c value and the loading concentration of the carbon black material in the polymer composite material, and calculating the thermal conductivity according to the formula k = A + B*OAN*L_c*loading concentration², wherein A is the thermal conductivity of the polymer without additive, and B is the slope of the straight line when plotting the thermal conductivity versus the value (OAN*L_c*loading concentration²); or

a method of preparing a polymer composite material comprising a carbon black material in particulate form dispersed in a polymer matrix and having a desired thermal conductivity k, the method comprising selecting a carbon black material having an OAN and an L_c value, choosing the loading concentration of the carbon black material in the polymer composite according to the formula k = A + B* OAN*L_c*(loading concentration)², and mixing the chosen loading concentration of the carbon black material with the polymer matrix.