| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain good fixing property and storage property by incorporating a coloring agent and a binder resin using a specified styrene acryl resin. SOLUTION: This developer contains a binder resin and a coloring agent. The binder resin contains a low mol.wt. styrene-acryl resin with the mol.wt. distribution having a peak in 3000 to 8000 range and a high mol.wt. styrene-scryl resin having a peak in 100000 to 400000 range. The Tg of the whole resin is 56 to 64 deg.C, and the starting temp. of the Tg endothermic process is >=45 deg.C for each of the low mol.wt. and high mol.wt. styrene acryl resin. The starting temp. L and H of the endothermic process of the low mol.wt. and the high mol.wt. styrene acryl resins, respectively, are preferably controlled to satisfy the relation of L>=H>=45 deg.C. Relating to the binder resin, the low mol.wt. styrene- acryl resin is preferably included by 30 to 70 wt.% based on the whole binder resin. Further, silica particles after hydrophobic treatment may be added by 0.1 to 1.5 wt.% based on the whole toner weight.</p> |
