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CARBON BLACK DICTIONARY

Chinese: 炭黑
Dutch: Industrieroet, Roet
French: Noire de Carbone
German: Industrieruß, Ruß
Hindi: कार्बन ब्लैक
Italian: Nero di Carbonio,  Nerofumo
Japanese: カーボンブラック
Polish: Sadza techniczna
Portuguese: Preto de Carbono, Negro de Carbono
Russian: Tехнический углерод, техуглерод, сажа
Spanish: Negro de Humo, Negro de Carbon
Turkish: İs karası

SUMMERY OF MAIN CARBON BLACK TERMS  

Aciniform: Shaped like a cluster of grapes. The spheroidal primary particles of carbon black are fused into aggregates of colloidal dimension forming an aciniform morphology.

Agglomerate: A cluster of physically bound and entangled aggregates. See Test Method ASTM D 3849.

Aggregate: A discrete, rigid, colloidal mass of extensively coalesced particles; it is the smallest dispersible unit.

Ash content: Content in % of ash in carbon black. See Test Method ASTM D 1506.

ASTM D: The most important target values of carbon black are described by ASTM methods (American Society for Testing Materials).

Carbon Black: An engineered material, primarily composed of elemental carbon, obtained from the partial combustion or thermal decomposition of hydrocarbons, existing as aggregates of aciniform morphology which are composed of spheroidal primary particles, uniformity of primary particle sizes within a given aggregate and turbostratic layering within the primary particles. Particle size and aggregate size (number of particles per aggregate) are distributional properties and vary depending on the carbon black grade. The particle and aggregate sizes vary greatly within a given grade of carbon black, the primary particle size is essentially uniform within an individual aggregate.

Carbon Black REACH Registration number: 01-2119384822-32-xxxx

Carcass grade Carbon Black: A type of furnace carbon black having an average particle size in the range from 31 to 200 nm. Carcass grade carbon blacks are produced by the oil furnace process. The use of these grades in the rubber industry is not limited to the carcass portion of the tire. These grades are designated with an “N” first character and a second character of “1, 2, 3, 5, 6 or 7” in Table 1 of Classification ASTM D 1765. See Terminology  ASTM D 1566 for the definition of carcass.

CAS Number of Carbon Black: 1333-86-4: Unique numerical ident assigned by Chemical Abstracts Service.

Compressed Oil Absorption Number (COAN): See oil absorption number of compressed sample, the preferred term.

EG Number of Carbon Black: EG 215-669-9 EG number is important to identify products in IUCLID

Fines content: That portion of pelleted carbon black that passes throught a specified sieves. See Test Method ASTM D 1508.

Furnace Carbon Black: A type of carbon black produced by the decomposition reaction of hydrocarbons when injected into a high-velocity stream of combustion gases under controlled conditions.

Hard Carbon Blacks: See tread grade carbon black, reinforcing carbon black, the preferred term. All carbon blacks provide some level of reinforcement when mixed in rubber. The amount of reinforcement is a function of the carbon black grade and amount used. See Terminology ASTM D 1566 for the definition of reinforcement.

Harmonised System HS Code of Carbon Black 28030000

Heating loss: Mass loss in % when carbon black is heated at 125°C for 1h; the heating loss is primarily attributed to moisture content. See Test Method ASTM D 1509.

Individual pellet hardness: The force required to fracture or crush a carbon black pellet. See Test Methods ASTM D 3313 and D 5230.

Iodine adsorption number: The number of grams of iodine adsorbed per kilogram of carbon black under specified conditions. See Test Method ASTM D 1510.

Lot: A defined quantity of carbon black that is essentially uniform in composition and characteristics.

Lot sample: A quantity of carbon black selected to represent a lot for testing purposes and taken in accordance with Practice ASTM D 1799 or D 1900.

Mass strength: A measure of the tendency for carbon black pellets to pack together and to influence flow in a bulk handling system. See Test Method ASTM D 937.

Microstructure: Arrangement of carbon atoms within a carbon black particles.

Moisture content: The percentage, by mass, of water absorbed and adsorbed by carbon black. See definition of carbon black heating loss. According to ASTM D 1509.

Nitrogen surface area (NSA): Nitrogen surface area of carbon black, defined by ASTM D 6556. Total and external surface area by Nitrogen Absorbtion.

Oil absorption number (OAN): The number of cubic centimeters of dibutyl phthalate (DBP) or paraffin oil absorbed by 100 g of carbon black under specified conditions. The OAN value is proportional to the degree of aggregation of structure level of the carbon black. See Test Methods ASTM D 2414 and D 3493.

Oil absorption number of compressed sample (COAN): The number of cubic centimeters of dibutyl phthalate (DBP) or paraffin oil absorbed by 100 g of carbon black after being compressed four times in a compression cylinder at 165 MPa (24 000 psi) under specified conditions. The COAN value gives some measure of the stability of the structure of the carbon black. See Test Methods ASTM  D 2414 and D 3493.

Oil furnace process: A process for producing furnace carbon blacks that uses oil as the source of hydrocarbons for decomposition by injection into a high-velocity stream of combustion gases. Oil or natural gas are typically used as combustion fuel to create the high-velocity stream of combustion gases, although other fuels may be used.

Particle: A small spheroidally shaped (paracrystalline, non-discrete) component of a carbon black aggregate; it is separable from the aggregate only by fracturing.

Particle diameter: Arithmetic average of the diameters of particles within a carbon black aggregate as measured by electron microscopy. See Test Method ASTM D 3849.

Pellet: A relatively large agglomerate mass that has been densified in spheroidal form to facilitate handling and processing. See Test Method ASTM D 1511.

Pellet size distribution: The percentage, by mass, of carbon black retained on each of a specified series of sieve screens arranged with progressively smaller openings. See Test Method D 1511.

Pigment 6 PBK – 6 international Color index of Carbon Black

Pigment 7 PBK – 7 International Color index of Lamp Black

ph-Value: According to ASTM D 1512.

Pour density: Mass per unit volume of carbon black, determined in kg/m3. See Test Method ASTM D 1513.

Recovered Carbon Black (rCB): Recovered Carbon Black (rCB) became one of most popular topics the last years in correlation with the carbon black market. The main idea of rCB is to transform rubber waste into valuable commercial products. Due to innovations and technology improvements pyrolyse process became more efficient and environment friendly. On the other side the end of life tires (ELT) disposal represents a global environmental problem. Statistics show that 1,5 billion ELT’s are generated every year worldwide. The production of recycled carbon black is devided into several stages, as carbon powder is not the only raw material obtained from recycled tires. After pyrolysis treatment the process basically produces char, hydro carbon oil, steel, carbon composite and gas (which usually remains inside the installation as energy generator). By some players rCB is introduced to substitute standard furnace carbon blacks. This carbon powder (rCB) is not the same as virgin Carbon Black. Carbon black is an almost pure elemental carbon produced from heavy petroleum feedstock. Purity is key difference in comparisment to the recovered carbon black which is produced from solid fraction. Tires produced from compounds and various chemical compositions, contain several contaminants and impurities (textiles, steel etc.). Those differences are visible on most datasheets with a much higher ash content, due to the used silica in tread compounds. It is difficult to compare and classify recovered carbon black in comparisment with a virgin one, as virgin Carbon Black is produced with raw materials derived from petroleum, while the recovered one has a big variety of feedstock and process types. In some applications rCB is used in small loadings as a filler or low-end colorant, however it cannot substitute for virgin carbon black as it does not offer the same level of performance. Nevertheless we are convinced that rCB will find its place in the growing carbon black market, especially because the big tire manufacturers are involved in these projects. In our opinion any solution which is environmentally friendly and helps reduce the CO2 footprint is to be supported.

Reinforcing Carbon Black: See tread grade carbon black, the preferred term. All carbon blacks provide some level of reinforcement when mixed in rubber. The amount of reinforcement is a function of the carbon black grade and amount used. See Terminology ASTM D 1566 for the definition of reinforcement.

Rubber Carbon Black: The nomenclature currently used for the rubber grade carbon blacks was instituted by the D 24ASTM Committee on carbon black in 1968. It consists of a prefix letter followed by a three-digit number. The prefix, either N or S indicates whether the grade is a (N)ormal or a (S)low curing material. When the system was developed channel blacks were still commonly used and were slow curing. Afterwards, a fifty-fold increase in natural gas price ended rubber grade channel black production. For a time furnace grades treated to emulate the cure characteristics of channel were available. These too have largely disappeared leaving little need for or use of the “S” prefix letter. Consequently, most (if not all) currently active rubber grades carry the prefix “N”.

Semi-reinforcing Carbon Black: See carcass grade carbon black, the preferred term. All carbon blacks provide some level of reinforcement when mixed in rubber. The amount of reinforcement is a function of the carbon black grade and amount used. See Terminology ASTM D 1566 for the definition of reinforcement.

Soft Carbon Black: See carcass grade carbon black, semi-reinforcing carbon black, the preferred term. All carbon blacks provide some level of reinforcement when mixed in rubber. The amount of reinforcement is a function of the carbon black grade and amount used. See Terminology  ASTM D 1566 for the definition of reinforcement.

Statistical Thickness Surface Area (STSA): The external surface area of carbon black that is calculated from nitrogen adsorption data using the de Boer theory and a carbon black model. See Test Methods ASTM D 5816- 6556.

Structure: The quality of irregularity and deviation from sphericity of the shape of a carbon black aggregate.

Sulphur content: Content in % of sulphur in carbon black. See Test Method ASTM D 1619.

Surface activity: The inherent ability of the carbon black surface to interact physically or chemically, or both, with rubber or other molecules.

Unfortunately there is no direct method for measuring carbon black surface activity. The term refers to the chemical reactivity of the surface. Surface activity is influenced by the graphitic plane orientation as well as the number and type of organic side groups. On a molecular level, carbon black is composed of amorphous graphite layer planes created from the condensation of aromatic rings. The edges of such planes have unsatisfied carbon bonds which can act as chemical reaction sites.

The reaction time for the production of thermal black is long in comparison to the furnace black process. Long reaction times combined with the high temperature required for the thermal decomposition of natural gas feed stock (1300 ̊C) allows the graphite layer planes of thermal black to become highly ordered so that only layer plane surfaces are at the surface of the particle. As a result, no unsatisfied carbon bonds at the layer plane edges are exposed and therefore no potential reaction sites for elastomer interaction are present in thermal black. Conversely, the shorter reaction times used in making furnace black produce layer planes at the surface which are less ordered, resulting in numerous sites for chemical bonds with elastomers.

Recent scanning tunneling electron microscopy (STM) studies, which characterize the surface of carbon black, clearly support the fact that larger particle size carbon blacks like thermal black tend toward a more organized surface structure with fewer active sites.

The formation of thermal black occurs in the absence of flame or air while furnace black is generally the product of incomplete combustion of petroleum refinery residues. As a result, furnace blacks contain numerous types of organic functional groups such as phenols, hydroxyls, lactones and quinones which also contribute to the level of surface activity. The same organic functional groups are virtually absent from thermal black.

Carbon blacks with a high amount of surface activity often provide high reinforcement. While thermal black does impart some degree of reinforcement to elastomers it is most often referred to as an inactive or non-reinforcing black.

The influence of carbon black on rubber can best be described in terms of processing and vulcanizate properties. In choosing carbon black(s) for an elastomer formulation, the grade of carbon black and the degree of loading must be taken into consideration. The general effects of carbon black on any given rubber property can be summarized according to surface area (particle size), structure and loading level.

Surface area CTAB: (Formerly Test Method ASTM D 3765) Has been withdrawn. The CTAB value may be estimated from the STSA value using Eq 1. The equation is based on a linear regression of the STSA and CTAB measured values of the SRB 5 standards. CTAB 5 STSA * 1.0170 1 2.6434.

Target value: A consensus value for selected primary properties on which producers center their manufacturing process and users center their specification. Target values for carbon black properties are shown in Classification ASTM D 1765 for most rubber grade carbon blacks currently in commerce.

Thermal Carbon Black: One of the purest carbon blacks, which is often referred to as medium thermal carbon black, produced under controlled conditions by the thermal decomposition of hydrocarbons in the absence of air or flames. These grades are designated with an “N” first character and a second character of “8 or 9” in Table 1 of Classification ASTM D 1765.

Tint strength: The ratio, expressed as tint units, of the reflectance of a standard paste to a sample paste, both prepared and tested under specified conditions. See Test Method ASTM D 3265.

Toluene discoloration: The transmittance, at 425 nm, of the filtrate obtained from the toluene extract of carbon black, compared with that of pure toluene. See Test Method ASTM D 1618.

Tread grade Carbon Black: A type of furnace carbon black having an average particle size in the range from 1 to 30 nm. Tread grade carbon blacks are produced by the oil furnace process. The use of these grades in the rubber industry is not limited to the tread portion of the tire. These grades are designated with an “N” first character and a second character of “0, 1, 2, or 3” in Table 1 of Classification  ASTM D 1765.

Typical value: A consensus value for those carbon black properties that are not specifically targeted for control in the manufacturing process and that are somewhat dependent upon the targeted properties. Typical values for carbon black properties are shown in Classification ASTM D 1765 for most rubber grade carbon blacks currently in commerce. These are consensus values based upon the range in values supplied by the manufacturers. Typical values are useful in making comparisons between grades but they are not the set-point targets for the process and may be expected to differ significantly between producers.

Weight mean particle size: ratio equal to the sum of individual particle diameters, each raised to the fourth power, divided by the sum of the individual particle diameters, raised to the third power.