INVESTIGATIONS ON THE SURFACE AND SELVEDGE PROPERTIES OF RUBBER BLACKS AND COLOR BLACKS

The surfaces and the surface near regions of different grades of carbo n black and of graphites were investigated by means of SIMS. Hard blac ks and improved grades of hard blacks showed higher relative surface c oncentrations of hydrogen and higher integral concentrations of hydrog en than soft blacks. The C-2(-)/C2H- ratios measured with increasing m aterial erosion rates showed significant variations indicating differe nt concentration profiles of hydrogen. These properties correlate to t he specific production parameters. Different sensitivities to controll ed oxidation were observed for hard and soft furnace blacks in the flu ffy state and for an improved hard furnace black (N234) in the fluffy, wet pelletized and graphitized condition. The results are discussed i n the context of previous work by means of STM (Scanning Tunneling Mic roscopy) and IGC (Inverse Gas Chromatography). Comparison of the fragm entation patterns of non-pelletized, dry pelletized and wet pelletized carbon blacks showed that surface modifications are induced which are insensitive to subsequent extraction procedures.