The Chemical Durability of SiO_2-Na_2O-Oxide of Transition Element System Glasses (2nd Report) : SiO_2-Na_2O-TiO_2 System

The chemical durability of glasses, especially water resistant quality, was studied in this paper. Fourteen kinds of glasses in SiO_2-Na_2O-TiO_2 system were fused in electric furnace. The fused glasses were powdered into particles of 35-60meshes and 2g of them were immersed in 50 ce water of 30,50 and 70℃ while being stirred during 10,20,40 and 80 minutes respectively. Then the amounts of titanium dissolved into weter were measured by chelatometrie titration. In this paper, author considered the behavior of dissolution in SiO_2-Na_2O-TiO_2 system glasses and compared the dissolving phenomena of SiO_2-Na_2O-V_2O_5 system with that of SiO_2-Na_2O-TiO_2 system. The results are as follows. 1) The experimental data were tested by analysis of variance and its was proved that log of dissolved amounts was linear function of reciprocal of absolute temperature and had no linear relation to dissolving time as a whole, but there were linear relations between log of dissolving amounts and stirring time in the case of 20 and 80 minutes. 2) The dissolved amounts increased with increasing Na_2O mol in TiO_2 10 and 30mol, and in TiO_2 20mol there was minimum value of the dissolved amounts at certain composition. In glasses of SiO_2 60mol, the dissolved amounts decreased with increasing Na_2O mol. 3) The chemical durabilify of SiO_2-Na_2O-TiO_2 system glasses is very superior to that of SiO_2-Na_2O-V_2O_5 system. 4) The apparent energy of dissolution of Si_2O-Na_2O-TiO_2 system glasses is small in comparison with that of SiO_2-Na_2O-V_2O_5 system.

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