Aqueous Sheet Forming of Zirconia Using an Emulsion of Urethane Polymer
Koji INAOKACHaruhisa SHIOMICHirofumi INADA and Masatoshi SATO
Abstract:Aqueous partially stabilized zirconia sheets were fabricated using an emulsion of urethane polymer as a binder. The effects of the concentration of dispersant, the organic binder and the solid loading of slurry were measured using a viscometer with a coaxial cylinder sensor system on the properties of the slurry. The degree of cracking on drying was evaluated with eyes on the sheets obtained from the slurries of various compositions. The obtained results are as follows, (1) The slurry containing the high concentration of dispersant and the organic binder exhibited Newtonian flow. The slurry showed the hysteresis characteristics for high solid loading. The change in the apparent viscosity of the slurry with binder content was remarkable at high solid loading. (2) When the concentration of dispersant and the binder were high, and thus the viscosity of the slurry was low, crack-free sheets were obtained. The void resulting from air-bubbles in the slurry remained in the sheet at higher viscosity. (3) At constant solid loading, the apparent density of the sheet was independent of the concentration of dispersant and went down as that of the organic binder rose. At low binder content, the apparent density of the sheet prepared at low solid loading was high. However, at high binder content, the dependence of the apparent density on the solid loading was not observed. Key Words:Aqueous sheet, Partially stabilized zirconia, Emulsion of urethane, Viscosity, Apparent density