| 摘要 |
<p>PURPOSE:To form excellent visual images without decrease in electrification holding property or flowing property of a toner by using a hydrophobic silica fine particles obtd. by treatment to give >=80 hydrophobicity to the fine particles. CONSTITUTION:This electrostatic charge image developer compsn. contains a binder resin essentially comprising a polyester resin obtd. by condensation copolymn. of the following components. A diol component expressed by formula I (wherein R is ethylene or propylene group, x and y are integers >=1 with 2-7 average of x+y) by <10mol% of the whole structural components. A diol component expressed by formula II (wherein n is an integer of 2-6 by >=10mol% and >=25mol% of the whole structural components. A bivalent carboxylic acid, its anhydride, or lower alkylester and a tervalent or higher valent carboxylic acid, its anhydride or lower alkylester by >=2.5mol% and <15mol%. In this compsn. hydrophobic silica having 80 hydrophobicity is added by 0.01-1.5 pts.wt. to 100 pts.wt. of the toner.</p> |
