... 2.usage:rubber,plastic etc Carbon black 1. Type: n220,n330,n550.n660,n326,n3752. Place of origin: china3. Standard: GB ... 3778-20034. Form: black granule or powderItems N220 N330 N550 N660 Iodine Absorption Number g/kg121 +/-582 +/-543 +/-436 ... -1.7 +/-1.3-3.5 +/-1.3 Carbon black N330