| 摘要 |
PURPOSE:To provide high electric charge holdability to a titled toner by dispersing and incorporating a carbon black having a specific oxygen content into a binder resin. CONSTITUTION:The carbon black having >=6% oxygen content is dispersed and incorporated into the binder resin. A channel type carbon is particularly preferable as the carbon black. The carbon black having <=4.0pH and >=10% volatile component is more preferable. The toner is usually obtd. in the form of fine powder particles having 10-15mu grain size by melting and kneading raw materials and subjecting the melt to crushing then to pulverizing. Substantially high potential is maintained in the copying and printing of the toner image after heat fixing and the high image density is obtd. at the time of copying and printing when such toner is used for forming a printing master. The dissipation and implantation of electric charge by electrical conduction are prevented by selecting the carbon black having low electrical conductivity and contg. an acidic surface functional group at a high ratio for the toner. |
