| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain an electrostatic charge image developing carrier having improved durability and flow property by providing the surfaces of magnetic material particles with coating layers consisting of crystalline resins specified in crystallinity. SOLUTION: The surfaces of the magnetic material particles are provided with the coating layers consisting of the crystalline resins having the crystallinity of 50 to 95%. In such a case, the sufficient improvement of the mixing property of the developers is not possible if the crystalinity is below 50%. When the crystallinity exceeds 95%, the brittleness of the resins is significant and, therefore, a problem arises in the durability. The method for measuring the crystallinity includes an NMR method, X-ray method, IR method, density method, DSC method, etc. In such a case, the crystallinity determined by the density method is used. The crystalline resins include more specifically polyamide, such as, for example, polyethylene, polypropylene, polybutene, polystyrene, polyvinyl chloride, polyethylene terephthalate, polytetrafluoroethylene, polychloroprene, nylon 66 and nylon 6.</p> |
