| 摘要 |
PURPOSE:To form a developer capable of obtaining a sharp image of high quality and free from fog by using a positive chargeable binder resin superior in resistance to environmental conditions. CONSTITUTION:An electrophotographic dry type developer composed essentially of a binder resin and a colorant uses as a binder resin composed essentially of a polymer obtained by suspension-polymerizing 98-99.95pts.wt. hydrophobic copolymerizable monomer and 0.05-2.0pts.wt. copolymerizable monomer contg. tertiary amine group represented by formula I in the presence of 0.5-5.0pts.wt. azonitrile type polymn. initiator. In formula I , R1 is H or methyl; X is -COO- or -CONH-; R2, R3 are each 1-4C alkyl or aryl; and n is an integer of 1-4. The hydrophobic copolymerizable monomer has <=1.0wt% water solubility or it dissolves <=1.0wt% water, and as the azonitrile type polymn. initiator, azobisisobutyronitrile, etc. are desirable. |
