A glass substrate for use as the substrate of an information recording medium such as a magnetic disk, magneto-optical disk, DVD, or MD or of an optical communication device, and a glass composition for making such a glass substrate, contains the following glass ingredients: 45 to 75% by weight of S
A glass substrate for use as the substrate of an information recording medium such as a magnetic disk, magneto-optical disk, DVD, or MD or of an optical communication device, and a glass composition for making such a glass substrate, contains the following glass ingredients: 45 to 75% by weight of SiO2; 1 to 20% by weight of Al2O3; 0 to 15% by weight, zero inclusive, of B2O3; SiO2+Al2O3+B2O3 accounting for 65 to 90% by weight; a total of 7 to 20% by weight of R2O compounds, where R=Li, Na, and K; and a total of 0 to 12% by weight, zero inclusive, of R'O compounds, where R'=Mg, Ca, Sr, Ba, and Zn. Moreover, the following conditions are fulfilled: B2O3=0% by weight, or Al2O3/B2O3≧1.0; and (SiO2+Al2O3+B2O3)/(the total of R2O compounds+the total of R2O compounds)≧3.
대표청구항▼
What is claimed is: 1. A glass composition comprising the following glass ingredients: 45 to 75% by weight of SiO2; 10.1 to 14.6% by weight of Al2O3; 1.2 to 5.7% by weight of B2O3; SiO2+Al2O3+B2O3 accounting for 65 to 90% by weight; a total of 7 to 12.8% by weight of R2O compounds, where R=Li, Na,
What is claimed is: 1. A glass composition comprising the following glass ingredients: 45 to 75% by weight of SiO2; 10.1 to 14.6% by weight of Al2O3; 1.2 to 5.7% by weight of B2O3; SiO2+Al2O3+B2O3 accounting for 65 to 90% by weight; a total of 7 to 12.8% by weight of R2O compounds, where R=Li, Na, and K; and a total of 0% by weight of R'O compounds, where R'=Mg, Ca, Sr, Ba, and Zn; and a total of 0 to 7.1% by weight, zero inclusive, of TiO2+ZrO2+LnxOy, where LnxOy represents at least one compound selected from the group consisting of lanthanoid metal oxides, Y2O3, Nb2O5 and Ta2O5, wherein the following conditions are fulfilled: Al2O3/B2O3 ≧1.0; and 7.78≧(SiO2+Al2O3+B 2O3)/(the total of R2O compounds ≧3. 2. A glass composition as claimed in claim 1, wherein the glass composition has a glass transition temperature Tg of 600�� C. or lower. 3. A glass composition as claimed in claim 1, wherein the glass composition has a liquid phase temperature TL of 1 300�� C. or lower. 4. A glass composition as claimed in claim 1, wherein a temperature T log η=2 at which the glass composition has a melt viscosity of log η=2 is 1 550�� C. or lower. 5. A glass substrate formed of a glass composition comprising the following glass ingredients: 45 to 75% by weight of SiO2; 10.1 to 14.6% by weight of Al2O3; 1.2 to 5.7% by weight of B2O3; SiO2+Al2O3+B2O3 accounting for 72 to 90% by weight; a total of 7 to 12.8% by weight of R2O compounds, where R=Li, Na, and K; a total of 0% by weight of R'O compounds, where R'=Mg, Ca, Sr, Ba, and Zn; and a total of 0% to 7.1% by weight, zero inclusive, of TiO2+ZrO2+LnxOy, where LnxOy represents at least one compound selected from the group consisting of lanthanoid metal oxides, Y2O3, Nb2O5 and Ta2O5, wherein the following conditions are fulfilled: Al2O3/B2O3 ≧1.0; and 7.78≧(SiO2+Al2O3+B 2O3)/(the total of R2O compounds≧3. 6. A glass substrate as claimed in claim 5, wherein the glass composition has a glass transition temperature Tg of 600�� C. or lower. 7. A glass substrate as claimed in claim 5, wherein the glass composition has a liquid phase temperature TL of 1 300�� C. or lower. 8. A glass substrate as claimed in claim 5, wherein a temperature Tlog η=2 at which the glass composition has a melt viscosity of log η=2 is 1 550�� C. or lower. 9. A glass substrate as claimed in claim 5, wherein the glass substrate is not subjected to chemical strengthening. 10. A glass substrate as claimed in claim 9, wherein the glass substrate has a specific elastic modulus E/ρ of 31 or higher. 11. A glass substrate as claimed in claim 9, wherein the glass substrate has a Vickers hardness Hv in a range of from 500 to 700 as measured at a load of 100g. 12. A glass substrate as claimed in claim 9, wherein the glass substrate has alkali elution A of 350 ppb or lower per 2.5-inch disk. 13. A glass substrate as claimed in claim 9, wherein the glass substrate has a linear thermal expansion coefficient in a range of from 60��10--7/�� C. to 90 10--7/�� C. within a temperature range of 25 to 100�� C. 14. A glass substrate as claimed in claim 9, wherein the glass substrate has a fracture toughness Kc of 0.80 or greater.
Kishimoto, Shoichi; Koyama, Akihiro; Tanaka, Hiroyuki; Yamamoto, Nobuyuki, Glass article and glass substrate for information recording media using the same.
Ikenishi, Mikio; Morita, Atsuko; Zou, Xuelu, Glass substrate for information recording medium and magnetic information recording medium to which the glass substrate is applied.
Nagashima, Tatsuo; Nagai, Kensuke; Nakashima, Tetsuya; Maeda, Kei, Glass for data storage medium substrate, glass substrate for data storage medium and magnetic disk.
Nagashima, Tatsuo; Nagai, Kensuke; Nakashima, Tetsuya; Maeda, Kei, Glass for data storage medium substrate, glass substrate for data storage medium and magnetic disk.
Endo, Jun; Nagashima, Tatsuo; Nakashima, Tetsuya; Diaz Reyes, Manuel, Glass for information recording medium substrate, glass substrate for information recording medium and magnetic disk.
※ AI-Helper는 부적절한 답변을 할 수 있습니다.