Carbonation reaction of (Ca,Mg)O protective layer on plasma display panel

We have been applying a low discharge voltage (Ca, Mg)O protective layer to plasma display panels to reduce their power consumption. However, (Ca, Mg)O is highly reactive with CO₂, and the resulting carbonate formation during high‐temperature panel sealing in air impairs the low discharge voltage characteristic. We investigated the mechanism of the carbonation reaction that occurs on a (Ca, Mg)O surface during annealing in air at 450°C and found that the CO₂ diffuses through the formed CaCO₃ layer and that a (Ca, Mg)O + CO₂ → CaCO₃ + MgO reaction then occurs. This carbonation reaction evidently stops when the growing MgO finally forms a layer at all boundaries between the CaCO₃ and (Ca, Mg)O regions.