| 摘要 |
PURPOSE:To obtain a carrier which has an excellent carrier life and mechanical strength and povides a sharp picture image without influence of moisture by making the content of O in the surface compsn. of carrier particles using ferrite larger than the content thereof in the inside of the particles. CONSTITUTION:In the stage of mixing and calcining 15% NiO, 30% ZnO and 50% Fe2O3, and grinding the calcined mixture then calcining the granules after granulating the ground mixture by using an aq. soln. of PVA or the like, O2 is flowed in a furnace and carrier particles contg. O slightly more on the surface than in the inside are obtained. The carrier contg. O at a high rate on the surface than ordinary ferrite carriers has a >=2-times longer life than conventional ferrite carriers, has high mechanical strength and provides a picture image which is stable to moisture and is always sharp. |
