Effect of Characteristics of Polyvinyl Butyral on Al_2O_3 Tape Casting Slurry

The effect of solubility,film-forming ability and the dispersion of polyvinyl butyral(PVB) on Al2O3 tape casting slurry were studied.The results show that the PVB polymer solution exhibits the lowest viscosity in the binary solvent(EtOH)/Xylene of 60% ethyl alcohol.The viscosity of slurry is 868 mPa·s in the absence of dispersant whereas the viscosity decreases to 17 mPa·s with 0.5% PVB as the dispersant at the shear rate 50 s-1.When 8% PVB is added as the binder in the slurry,the slurry exhibits lower viscosity;the green tape shows better film-forming ability and has no obvious defaults.