| 摘要 |
PURPOSE:To break bond between refractory particles with a resin and to obtain coated refractory particles comprising thin resin coating having excellent water resistance, release resistance, not reducing sintering properties by blending a solution of urethane resin in a solvent with a refractory particle group, drying and curing. CONSTITUTION:A urethane resin is diluted with an ester based solvent such as ethyl acetate not containing active hydrogen to prepare a resin solution having <=200cPs/25 deg.C low viscosity. The urethane resin solution is mixed with a refractory particle group, blended at room temperature by a blender such as high-speed mixer or universal type mixer, dried and cured. Consequently, bond between the coated refractory particles with a resin is broken to give refractory particles coated with urethane resin. The amount of the urethane resin added is preferably 1-15wt.% based on the refractory particles. |
