| 摘要 |
<p>PROBLEM TO BE SOLVED: To facilitate recycling of a carrier, to ensure the sticking of a core material to a resin and to maintain superior electrostatic property over long periods of time by adding a resin whose saturation solubility in water varies according to acidity or temperature to a coating layer. SOLUTION: A resin, whose solubility in water or an aqueous solution varies according to acidity or temperature, is added to a resin which coats the core material of a carrier. The resins are mixed and the core material is coated with the mixture to form a coating layer or the core material is coated with the former resin and then coated with the latter resin to form the outermost layer. The resulting carrier is used, and after lapse of its service period, the carrier is washed with washing water at such an acidity or temperature as to ensure high dissolving power. The resin coated layer is removed, and the core material is recovered and recoated to enable regeneration of the carrier. The resin added is not limited, as long as it is slightly soluble in an aqueous solvent at room temperature and exhibits water solubility at the regeneration temperature. A reaction product of polyvinyl alcohol and aldehyde, polyvinyl ether or polyvinyl aminoacetate may be used as the resin.</p> |
