Method for producing glass substrate
AssigneeNippon Electric Glass Co., Ltd.
InventorsMasahiro Hayashi, Mayu Fujii
Life of this patent
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Abstract
Provided is a method for producing a glass substrate that can reduce the dimensional change during heat treatment while avoiding shortening of facilities' service lives. A method for producing a glass substrate includes melting and forming a glass raw material to produce a glass substrate having a strain point of 690 to 750° C., wherein an average cooling rate in a temperature range from (an annealing point plus 150° C.) to (the annealing point minus 200° C.) in a cooling process during the forming is adjusted to 100 to 400° C./min to obtain the glass substrate having a degree of thermal contraction of 15 ppm or less when subjected to a heat treatment at 500° C. for an hour.
Claims4
A method for producing a glass substrate, comprising:
- melting and forming a glass raw material to produce a glass substrate having a strain point of 710 to 750° C., wherein an average cooling rate in a temperature range from (an annealing point plus 150° C.) to (the annealing point minus 200° C. in a cooling process during the forming is adjusted to 200 to 400° C./min to obtain the glass substrate having a degree of thermal contraction of 15 ppm or less when subjected to a heat treatment at 500° C. for an hour and β-OH value of 0.30/mm or less;
- and
- the glass substrate containing, as a glass composition in terms of % by mole, 60 to 75% SiO2, 10 to 15% Al2O3, 0 to 5% B2O3, 0 to 0.1% Li2O, 0 to 0.1% Na2O, 0 to 1% K2O, 0 to 8% MgO, 0 to 10% CaO, 0 to 10% SrO, 0.1 to 10% BaO, 0 to 10% ZnO, 0 to 10% P2O5, and 0 to 1% SnO2.
Dependencies are inferred from the claim text.