Carbon black, esp. furnace black useful for pigmenting paint, ink or resin - is prepd. by oxidising carbon black with ozone to increase blackness

摘要

C black (I) has a ratio of a max. absorption in the 1800-1670 cm-1 region to a max. absorption in the 1670-1500 cm-1 range of not less than 0.65, taking a straight line joining the absorptions at 1805 cm-1 and 900 cm-1 in the absorption diagram of the IR absorption spectrum as base line. Also claimed is furnace black (IA), in which the said ratio is not less than 0.5. (I) and (IA) are obtd. by oxidn. of C black or furnace black with O3. The said ratio is pref. 0.65-2.0 for (I) and (IA). In an example, 10 g. furnace black with a particle size of 13 nm. and BET specific surface area of 360 m2/g. were treated for 100 hrs. in 0.6 1/min. gas contg. 0.2 g/hr. O3. The prod. had a max. absorption ratio of 0.78, cf. 0.25 for the starting material. The Hunter lightness (L value), determined in paint, was 3.87, cf. 5.19 for the starting material.