Full definition
Finely divided elemental carbon produced by incomplete combustion or thermal decomposition of heavy petroleum oils, serving as the most important reinforcing filler in the rubber industry. Adding 30-80 phr of carbon black to rubber dramatically increases tensile strength (2-5x), abrasion resistance (5-10x), modulus, tear resistance, and UV protection. Classification per ASTM D1765 by particle size (surface area) and structure (aggregate complexity): N110-N121 (SAF, super abrasion furnace, 15-20 nm — maximum reinforcement for tire treads), N220-N234 (ISAF, 20-25 nm — excellent for belt covers and premium products), N330 (HAF, 28-36 nm — most widely used general-purpose grade), N550 (FEF, 40-48 nm — good for belt compounds, extrusions), N660 (GPF, 49-60 nm — semi-reinforcing for inner tubes, cable), N762-N990 (thermal blacks, 100-500 nm — fillers with minimal reinforcement, for cost reduction). Key properties measured: iodine adsorption number (surface area, ASTM D1510), DBP absorption (structure, ASTM D2414), and tint strength. Global production: ~15 million tonnes/year, 70%+ consumed by tire industry. Major producers: Birla Carbon, Cabot, Orion, Tokai.