| 摘要 |
PURPOSE:To obtain a stable developer which obviates fluctuation of the electrifying power of a carrier coated with a silicone resin with an org. tin compd. as a catalyst on the surface by providing a gradient of catalyst concn. in the thickness direction of the silicone resin coating layer. CONSTITUTION:An org. tin compd. as a curing catalyst has the structure expressed by the formula. A soln. prepd. by dissolving a resin-modified silicone resin in an org. solvent, etc. is coated on nucleus particles for a carrier by a fluidized bed method. Optional materials including, for example, a magnetic metal such as iron, nickel or the like, carborundum, silicon dioxide, etc. are usable for the nucleus particles for the carrier. The Q/M of the developer is stabilized without decrease by making the catalyst concn. higher in the inner part of the silicone resin coating layer if the electrifying power of the silicone carrier decreases and the Q/M of the developer decreases with a decrease in the silicone resin coating layer as a result of repeated use of the developer. The catalyst is incorporated less in the inner part than in the surface layer part when the Q/M of the developer increases. |
