反应详情

This example illustrates another method for preparing a carbon black product of the present invention. A pin pelletizer was charged with 200 g of a carbon black with a CTAB surface area of 350 m2/g and a DBPA of 120. A solution of 44.2 g of sodium sulfanilate in 95 g of water at 70° C. was added and the pelletizer was run for one minute. Twenty grams of water was added followed by 39.6 g of concentrated nitric acid. The pelletizer was run for an additional minute. Twenty grams of water was added followed by a solution of 16.76 g of sodium nitrite in 35 g of water, forming 4-sulfobenzenediazonium hydroxide inner salt in situ, which reacted with the carbon black. After running the pelletizer for five minutes, a solution of 11.22 g of sodium hydroxide in 35 g of water was added. The pelletizer was run for an additional two minutes and the resulting a carbon black product was subsequently dried. Soxhlet extraction with ethanol overnight gave a carbon black product with 3.3% sulfur, compared against 0.5% for the untreated carbon black. This shows that 77% of the p-C6H4SO3-- groups were attached to the carbon black product. Therefore, the carbon black product had 0.88 mmol/g of attached p-C6H4SO3 -- groups.