| 摘要 |
PURPOSE:To form a resin coating layer having high uniformity and adhesive property in a short period of time by forming the carrier which satisfies specific relations between the circumferential speed for stirring and material temp. in a mixing stage, and the circumferential speed for stirring, material temp. and the glass transition point of resin particles for coating in a film forming stage. CONSTITUTION:The circumferential speed for stirring in the process for mixing of the core material particles and the resin particles for resin coating is designated as pa, the material temp. as Ta, the circumferential speed for stirring in the film forming stage for forming the resin coating layer by the resin particles for coating on the surface of the core material particles is designated as pb, the material temp. as pb, and the glass transition point of the resin particles for coating as Tg, then Pa>Pb, Ta<Tb, Ta<Tg, Tb<Tg+25 deg.C, Tb<110 deg.C are satisfied. The mixture in the state in which the resin particles for coating are densely and regularly arranged in the form of layers and are uniformly stuck onto the surfaces of the core material particles is, therefore, obtd. in a short period of time in the mixing process. The easy and secure fixing of the resin particles for coating adequately stuck to the surfaces of the core material particles is possible without liberating these particles in the film forming process. The resin coating layer having the high adhesive property and uniformity is formed in a short period of time in this way. |
