| 摘要 |
PROBLEM TO BE SOLVED: To obtain an ink excellent in light, heat and water resistances and capable of providing a high-grade print at a high density by treating a carbon black with an acid haliding agent, then reacting the resultant carbon black with an amine compound and adding a hydrophilic organic compound thereto. SOLUTION: A raw material carbon black is dispersed in an aprotic amide- based solvent and then treated with an acid haliding agent in an inert atmosphere such as a nitrogen atmosphere. The resultant carbon black is then reacted with an organic amine-based compound having a hydrophilic functional group comprising sulfo group, sulfinate group, carboxy group or a salt thereof to add the hydrophilic organic compound to the surface of the carbon black. The raw material carbon black preferably has >=0.1 mequiv./g content of surface acidic groups. Since the initial period of reaction is accompanied by heat generation, the reaction is preferably carried out while removing the heat with cold water, etc. The reaction is completed at room temperature to about 40 deg.C for several min. The acid haliding agent is used in a molar equiv. amount of 1-2 times based on the surface acidic groups of the carbon black. |
