| 摘要 |
PURPOSE:To improve the charge stability of a developer and to prevent the deterioration of image quality even after printing of many sheets by compounding the wet process silica subjected to a hydrophobic treatment by vapor reaction using a dimethyl silane compd. or trimethyl silane compd. as an external additive to a toner. CONSTITUTION:The powder which is the silica powder synthesized by a wet process and subjected to hydrophobic treatment on the surface by the vapor reaction with the dimethyl silane compd. or the trimethyl silane compd. is incorporated into the developer for electrostatic charge images. The wet process silica has fine pores in the internal structure and contains the many water molecules bonded by Van der Waals force to the silanol group of the pore surfaces and, therefore, the stable chargeability necessary for development is imparted to the toner. Further, the hydrophobic property is improved by heating the toner by the vapor reaction with the dimethyl silane compd. and/or the trimethyl silane compd. The adequate flowability and electrostatic charge stability are imparted to the toner in this way and the deterioration in the images is prevented. |
