| 摘要 |
PURPOSE:To improve the dispersion of an acidic carbon black so that blackness is enhanced and the formation of emulsified fine particles is lessened by treating the acidic carbon black with a prescribed amt. of aluminum coupling agent in a polymerizable monomer. CONSTITUTION:The acidic carbon black and 0.3-5wt.% aluminum coupling agent (e.g.: the compd. expressed by the formula) by the weight of said carbon black are added to the polymerizable monomer (e.g.: styrene) and is dispersed by an ultrasonic dispersion device, etc. A crosslinking agent, release agent, electrostatic charge control agent, etc., are then added at need to the resulted dispersion and the dispersion is subjected to suspension polymn. to form toner particles. The excess coupling agent is liberated and the emulsified fine particles are liable to be produced if the amt. of the coupling agent to be added exceeds 5%. The dispersibility of the carbon black is poor and the blackness is low if said amt. is below 0.3%. In the formula, R denotes alkyl of 1-20C; R' denotes alkyl or alkenyl of 1-20C. |
