| 摘要 |
The objective of the present invention is to provide a glass plate such that it is possible to suppress deformation of a glass product that is to receive a load in a heat treatment step at a temperature equal to the glass strain point or lower, such as in chemical strengthening and coating. The present invention relates to a glass plate for heat treatment wherein the dimensionless index determined by the formula below is 1.6 × 10-4 or lower, the average viscosity η is such that log η ≤ 15.1 log Pa・s or lower, and the relationship between the fictive temperature Tf and the annealing point Ta is Tf ≥ (Ta + 5); furthermore, when the glass thickness h is 7 × 10-4 m or greater, during the time a load is applied, the displacement at the load point is 78 μm or less. |
