混合アルカリ鉛珪酸塩ガラス融液の粘度

抄録

The viscosity of melts in the system R₂O (R=Na, K, Li+Na, Na+K, K+Li, and Li+Na+K)-PbO-SiO₂ was measured by the platinum ball pulling-up method at temperatures ranging from 1000° to 1400°C.
The results obtained are summarized as follows:
(1) In connection with the fact that the glass contains a small amount of alkali it is found that, on the molar basis. the potash glass is more viscous than the soda glass.
(2) The effect on the material that is charged with alkali is observable in the Li-K glass containing two different kinds of alkalis i.e., Li₂O and K₂O.
(3) In the Li-Na-K glass containing constant quantity of 2.5mol. %Li₂O or K₂O, the minimum of viscosity is observable at the molar concentration ratio (β_k and β_Na) of about 0.33. But, in the glass containing constant quantity of 2.5mol. %Na₂O, it is observable at molar concentration ratio (β_Li) of about 0.5.
(4) The same tendency of composition and the correlation between the viscosity and the apparent activation energy of viscous flow is also observable.