| 摘要 |
PURPOSE:To obtain an electrostatic image developer having high stability for positive charge, high durability, and high blocking resistance by incorporating a toner contg. a copolymer of a crystalline polyester with an amorphous vinyl polymer, and inorganic fine particles treated with an amino-modified Si compd. into an electrophotographic developer compsn. CONSTITUTION:Preferred functional groups contributing to a block copolymn. or a graft copolymn. of an ionically crosslinked amorphous vinyl polymer with a crystalline polyester are at least one selected from carboxyl group, OH group, etc., and a ratio of Mw(weight average mol.wt.) to Mn(number average mol.wt.) Mw/Mn in said amorphous vinyl polymer is necessary to be >=3.5. A toner contg. such copolymer is mixed with inorganic fine particles treated with an amino-modified Si compd. Such toner provides high fixing capacity at low temp., and high wettability in a molten state when it is used as a component of the crystalline polyester, and serves as it is as an ionically crosslinked vinyl polymer contributing to the improvement of fixing capacity at low temp. Thus, an electrophotographic developer having high blocking resistance, fluidity, and durability for copying use is obtd. |
