METHOD FOR REDUCING WARPAGE OCCURRING IN GLASS SHEET DUE TO CHEMICAL STRENGTHENING TREATMENT, METHOD FOR PRODUCING GLASS SHEET FOR CHEMICAL STRENGTHENING, AND METHOD FOR PRODUCING CHEMICALLY STRENGTHENED GLASS SHEET

摘要

The present invention is a method for reducing warpage of a glass sheet produced by a float process. This warpage occurs due to chemical strengthening treatment of the glass sheet. In the method of the present invention, a glass sheet produced by a float process is maintained in a temperature range from a temperature 70° C. lower than a strain point of the glass to a temperature 20° C. higher than the strain point for at least 10 minutes before the glass sheet is subjected to chemical strengthening treatment.