Effects of solvent composition on the rheological behavior of CaZrO3-based dielectrics and glass suspensions

Rheological behavior of ceramic suspensions consisting of CaZrO3, glass and polyvinyl butyral (PVB) in mixed solvents of toluene–ethanol–methyl ethyl ketone (MEK) for multi-layered ceramic capacitors (MLCC) with Cu internal electrodes was studied. The ceramic suspensions in 80 vol% toluene/20 vol% ethanol showed shear thinning behavior, leading to gelation with a dramatic increase in the viscosity. On the other hand, the suspensions with 20 vol% toluene/40 vol% ethanol/40 vol% MEK was more stable, exhibiting rheological behavior closer to Newtonian. Gelation behavior as well as rheological results was discussed in terms of chemical stability between PVB resins and the solvent composition.