| 摘要 |
PURPOSE:To prevent decrease of image density and increase of fog by incorporating a toner powder and a fine polymer or copolymer powder of an N-contg. monomer capable of addition polymn. having an average particle diameter smaller than that of this toner powder to prepare a developer. CONSTITUTION:A developer contains a mixture of a toner powder, e.g., having an average particle diameter of 3-20mum and a fine powder of a polymer or copolymer of an N-contg. monomer capable of addition polymn. having that of 0.05-5mum, preferably 0.1-2mum in an amt. of this fine polymer of 0.01-10wt%, preferably, 0.05-2.0wt% of the toner. Said N-contg. monomer for preparing a polymer or copolymer to be used for this fine powder is embodied by 2-vinylpyridine or 4-vinylpyridine, etc., and a monomer to be copolymerized with said monomer is embodied by styrene and its derivs, such as methyl- or dimethyl- styrene. |
