Toughened glass substrate and process for producing same
AssigneeNippon Electric Glass Co., Ltd.
InventorsHiroki Katayama, Masashi Tabe, Takuji Oka
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Abstract
Provided is a tempered glass substrate formed by a float method, comprising a bottom surface and a top surface, wherein a compression stress value of the bottom surface is larger than a compression stress value of the top surface.
Claims14
A tempered glass substrate formed by a float method, comprising a bottom surface and a top surface, wherein a compression stress value of the bottom surface is larger than a compression stress value of the top surface.
A glass substrate to be tempered formed by a float method, comprising a bottom surface and a top surface, wherein a compression stress value of the bottom surface is larger than a compression stress value of the top surface when the glass substrate to be tempered is immersed in a KNO3 molten salt at 440° C. for 6 hours.
A glass substrate to be tempered formed by a float method, wherein the glass substrate to be tempered has a warpage rate of less than 0.20% when the glass substrate to be tempered is immersed in a KNO3 molten salt at 440° C. for 6 hours.
A production method for a tempered glass substrate, comprising:
- a forming step of forming glass into a glass sheet by a float method to yield a glass substrate to be tempered;
- a polishing step of polishing a top surface of the glass substrate to be tempered and/or a bottom surface thereof;
- and
- a tempering step of applying ion exchange treatment to the glass substrate to be tempered so that the bottom surface has a larger compression stress value than that of the top surface.
Dependencies are inferred from the claim text.