Carbon Black
“Carbon black is a material produced by the incomplete combustion of heavy petroleum products such as FCC tar, coal tar, ethylene cracking tar, and a small amount from vegetable oil. Carbon black is a form of amorphous carbon that has a high surface-area-to-volume ratio, although its surface-area-to-volume ratio is low compared to that of activated carbon. It is dissimilar to soot in its much higher surface-area-to-volume ratio and significantly lower (negligible and non-bioavailable) PAH (polycyclic aromatic hydrocarbon) content. Carbon black is used as a pigment and reinforcement in rubber and plastic products.”
“The current International Agency for Research on Cancer (IARC) evaluation is that, "Carbon black is possibly carcinogenic to humans (Group 2B)". Short-term exposure to high concentrations of carbon black dust may produce discomfort to the upper respiratory tract, through mechanical irritation.”
(Wikipedia, Carbon Black, 10/11/2011)
“Carbon black has been used as a black pigment. In recent years, a carbon black pigment that is provided with improved dispersibility in water (i.e., polar solvent) via surface modification has been developed as a black coloring material for inkjet printers and the like.” [Kirino and Sekijama, US Patent 8,026,319 (9/27/2011)]
Recent US Patents
9/27/2011
8,026,319
Dispersible surface-modified carbon black
Kirino and Sekiyama of Tokai Carbon, Japan, developed a dispersible surface-modified carbon black that is surface-modified by causing a functional group on the surface of the carbon black to be bonded to a diol-modified end-containing polymer through a triisocyanate compound exhibits excellent dispersibility in a non-polar solvent, a low-polar solvent, and a resin. The dispersible surface-modified carbon black is characterized in that a surface functional group of the carbon black is bonded to one isocyanate end group of a triisocyanate compound having three isocyanate end groups, and the remaining two isocyanate end groups are respectively bonded to hydroxyl groups of a diol-modified end-containing polymer. (RDC 10/3/2011)