| 摘要 |
[PROBLEMS] A conventional silicate glass has such problems that the thermal conductivity is high and, when used in a thermal head, the power consumption of the thermal head cannot be reduced. [MEANS FOR SOLVING PROBLEMS] Disclosed is a phosphate glass which comprises (by mole) 50-68% of P<SUB>2</SUB>O<SUB>5</SUB>, 15-39% of CeO<SUB>2</SUB>, 2-7% of B<SUB>2</SUB>O<SUB>3</SUB> and 0.2-0.5% of Pr<SUB>6</SUB>O<SUB>11</SUB>, wherein the molar ratio of P<SUB>2</SUB>O<SUB>5</SUB> to CeO<SUB>2</SUB> satisfies the following relationship: 1=P<SUB>2</SUB>O<SUB>5</SUB>/CeO<SUB>2</SUB><4. Also disclosed is a phosphate glass which comprises (by mole) 50-65% of P<SUB>2</SUB>O<SUB>5</SUB>, 5-15% of CeO<SUB>2</SUB>, 3-8% of B<SUB>2</SUB>O<SUB>3</SUB>, 0-10% of Al<SUB>2</SUB>O<SUB>3</SUB>, 0-9% of BaO and Pr<SUB>6</SUB>O<SUB>11</SUB>, wherein the molar ratio of P<SUB>2</SUB>O<SUB>5</SUB> to CeO<SUB>2</SUB> satisfies the following relationship: 4=P<SUB>2</SUB>O<SUB>5</SUB>/CeO<SUB>2</SUB>. Each of the phosphate glasses has a low thermal conductivity. Therefore, when used as a glaze layer in a thermal head, the phosphate glasses enable to reduce the power consumption of the thermal head. Further, each of the phosphate glasses has the same thermal expansion coefficient as that of a ceramic substrate. Therefore, the phosphate glasses hardly cause the detachment from a ceramic substrate and have excellent heat resistance. |
