| 摘要 |
<p>PURPOSE:To obtain a toner and a developer excellent in crushability at the time of producing the toner while, sufficiently ensuring low pulverizability, less liable to variation in Q/M due to an environmental change, not causing surface stain or the scattering of the toner, giving an image having high faithfulness comparable to that of an initial image even at the time of continuous use and fit for high-speed fixation by using polyester resin having a specified crosslinking point density. CONSTITUTION:Polyester resin having a crosslinking point density of 0.06-0.25 represented by the equation is used as a binder for a toner. In the equation, (b) is the number of the functional groups of a crosslinking agent, the amt. of the crosslinking agent used is the percentage to the non-crosslinked part and the mol. wt. of the crosslinking agent is the wt. average mol.wt. of the cross-linking agent before crosslinking. The crosslinking point density shows the percentage of average mol.wt. per one crosslinking point and polyester has a higher crosslinking percentage in accordance with the decrease of the crosslinking point density. The objective toner excellent in crushability is obtd. without deteriorating anti-hot-offsetting property.</p> |
