| 摘要 |
PURPOSE:To enable formation of a uniform and thick outer shell of toner for electrophotography by mixing a low-melting point binder component and colorant, kneading, pulverizing into particles as the toner core, and adding high-melting point resin particles of specfied particle size to the surface of the toner core. CONSTITUTION:The binder component 1 and colorant 2 are kneaded 5 and pulverized 7 into particles as the toner core 7. The binder component 1 is low-melting point resin, wax, etc. The colorant 2 consists of pigment or dye. Then resin particles 3 are added 8 to the surface of the inner core 7 of the toner to obtain the toner core 9 covered with resin particles. These particles 3 consists of such a resin having higher melting point than the binder component 1 of the toner core 7, and has the particle size controlled from 0.1 to 3 mum. The toner core 9 dissolves the particles 3. The toner is subjected to coating teatment 10 with solvent 4 to obtain the toner 11 for electrophotography. The coating treatment 10 is done by dispersing the toner core 9 in the solvent when the resin particle-solvent system has slow dissolution rate, and then the toner is obtd. by filtering and drying or by spray drying method. For the system of high dissolution rate, the toner core 9 is subjected to solvent vapor treatment or solvent mist treatment. |
