| 摘要 |
PURPOSE:To obtain a dry toner suitable especially for the development of a negatively charged latent image and having high fixability at low temp. by using unsatd. polyester having functional groups contg. N from amine or the like as substituents for one or more COOH groups. CONSTITUTION:A graft copolymer having a crystalline stock polymer part of a polymer of one or more among ethylene, propylene and vinyl acetate, a stock polymer part of unsatd. polyester having one or more functional groups contg. N from amine, an ammonium salt, betaine, a pyridinium salt or azine as substituents for one or more COOH groups, and a vinyl-base stock polymer part is used to obtain a dry toner for developing an electrostatic latent image in an electrophotographic process. The graft copolymer has 40-70 deg.C glass transition point, 1,000-10,000 number average mol.wt. and 30,000-500,000 weight average mol.wt., and the crystalline polymer of main structural part has 45-200 deg.C m.p. The dry toner is a positively chargeable toner which contaminates hardly carrier particles, can be used in a wide temp. range and causes no offset phenomenon. |
