| 摘要 |
PURPOSE:To obtain a toner ensuring superior stability of image quality at the time of forming many copies at a low cost by suspension-polymerizing a polymerizable vinyl monomer with a nonionic dispersant and an azo initiator and using the resulting polymer as a binder. CONSTITUTION:A polymerizable vinyl monomer is suspension-polymerized with a nonionic dispersant and an azo initiator. PVA having 70-90% degree of saponification and 500-3,000 degree of polymn. is preferably used as the nonionic dispersant because it improves the characteristics of the resulting polymer as a binder for a toner. Azobisisobutyronitrile, 2,2'-azobis-(2,4- dimethylvaleronitrile), dimethyl-2,2'-azobisisobutyronitrile or 2,2'-azobis-(2- methylbutyronitrile) is preferably used as the azo initiator because it retains polymn. activity to the monomer, finishes polymn. in a relatively short time and hardly leaves a by-product produced by decomposition in the resulting polymer. |
