| 摘要 |
PURPOSE:To obtain a good background even after repeated uses, and high image density, by using toner particles contg. partially cross-linked polyester as a binder, and carrier particles obtd. by coating solid core particles with a mixture of butadiene-acrylonitrile rubber and polyurethane elastomer. CONSTITUTION:The toner preferably contains 88-90wt% partially crosslinked polyester resin having 58 deg.C glass transition point and 0.55 intrinsic viscosity in chloroform at 25 deg.C. A preferable amt. of toner in a developer is about 2wt%. The resin is the toner resin ''RES-D-0031'' made by Hercules Corp. in USA, and typically it has 23 acid value, 60 deg.C initial penetration point, 70 deg.C initial fluidized point, and 58 deg.C glass transition point. The carrier is obtained by coating solid core particles with a coating contg. an org. solvent-soluble resin mixture of butadiene-acrylonitrile rubber and polyurethane elastomer preferably by about 0.1wt% of the core. The particle diameter of such a core material is generally 30-1,000mum, usually, 100-600mum. |
