2012 年 60 巻 2 号 p. 21-26
Phosphate glass represents a potential substrate material for use in thermal transfer printing heads, because of its lower melting point and environmental friendliness compared with lead-based glass. However, conventional phosphate glass does not meet the practical criterion for durability against water. We found that the addition of cerium dramatically enhanced the water durability of phosphate glass, and that this was further improved by the addition of Al2O3. The aim of this study was to understand the mechanism for this enhanced water durability through TOF-SIMS analysis. The incorporation of cerium into conventional phosphate glass resulted in an increase negative fragment ions with a higher mass, indicating the presence of a highly polymerized phosphate structure, probably the longer chain structure was stabilized by chelation between cerium and oxygen. The ratio of linear chain structure to cyclic ring structure (polymetaphosphate) also increased when cerium was added. The spectrum of the Al2O3-added phosphate glass indicated that aluminum had been incorporated into polyphosphate chains and that this converted the chains from two-dimensional to three-dimensional structures. The intensity of fragment ions related to P4O10 decreases with an increase in the water durability of the glass samples.