| 摘要 |
<p>PROBLEM TO BE SOLVED: To produce a satisfactory carrier not generating an inversely charged toner by dissolving epoxy resin in a solvent, adding a straight-chain aliphatic polyamine and an acid anhydride, mixing them and carrying out heat curing. SOLUTION: Epoxy resin is dissolved in a solvent. Carbon black is added as an electrically conductive agent and they are mixed. A straight-chain aliphatic polyamine such as diethylenetriamine, triethylenetetramine or tetraethylenepentamine and an acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride or trimellitic anhydride are then added as curing agents. The mixture dissolved in the solvent is sprayed to coat the surface of a core (magnetic powder) by fluidized bed coating and hot air drying is carried out. The dried resin on the surface of the magnetic powder is cured by heating. Even when the heat curing is carried out in a stationary state, blocking is not caused.</p> |
