Method for manufacturing reinforced glass, and reinforced glass
Provided is a method of manufacturing a tempered glass, including an etching step of etching a plate-shaped or sheet-shaped chemically tempered glass having a compressive stress layer in a surface thereof. The method further includes a step of preparing, as the chemically tempered glass before the etching, a chemically tempered glass, which has in at least part thereof a bendable thin portion having a thickness t1 a , in which the thickness t1 a is 150 μm or less, in which a maximum compressive stress CSa in the compressive stress layer before the etching is 1,100 MPa or less, and in which a depth DOLa of the compressive stress layer before the etching is less than 15 μm. The etching step includes etching the chemically tempered glass so that an etching amount Δt on one surface of the chemically tempered glass is 0.25 μm or more and 3 μm or less.
1 . A method of manufacturing a tempered glass, the method comprising:
an etching step of etching a plate-shaped or sheet-shaped chemically tempered glass having a compressive stress layer in a surface thereof, and
a step of preparing, as the chemically tempered glass before the etching, a chemically tempered glass,
which has in at least part thereof a bendable thin portion having a thickness t1a,
in which the thickness t1a is 150 μm or less,
in which a maximum compressive stress CSa in the compressive stress layer before the etching is 1,100 MPa or less, and
in which a depth DOLa of the compressive stress layer before the etching is less than 15 μm,
wherein the etching step comprises etching the chemically tempered glass so that an etching amount Δt on one surface of the chemically tempered glass is 0.25 μm or more and 3 μm or less,
wherein the etching causes a maximum value CTb of an internal tensile stress of the chemically tempered glass after the etching, which is determined by the following equation (A), where t1b represents a thickness of the bendable thin portion after the etching, CSb represents a maximum compressive stress in the compressive stress layer after the etching, and DOLb represents a depth of the compressive stress layer after the etching, to be 240 MPa or more and 450 MPa or less,
CTb=CSb ×DOLb/( t 1 b− 2×DOLb) (A), and
wherein the etching causes the depth DOLb of the compressive stress layer after the etching to be 14.75 μm or less.
2 . The method of manufacturing a tempered glass according to claim 1 , wherein the etching causes
the thickness t1b of the bendable thin portion after the etching to be 149.5 μm or less, and
the maximum compressive stress CSb in the compressive stress layer after the etching to be 400 MPa or more and 950 MPa or less.
3 . The method of manufacturing a tempered glass according to claim 1 ,
wherein the chemically tempered glass before the etching comprises a plurality of thick portions each having a thickness t2a larger than the thickness t1a of the bendable thin portion before the etching,
wherein the thickness t2a is more than 150 μm, and
wherein the bendable thin portion before the etching extends in a band shape between the plurality of thick portions.
4 . The method of manufacturing a tempered glass according to claim 1 , wherein the chemically tempered glass before the etching has a substantially uniform sheet thickness.
5 . The method of manufacturing a tempered glass according to claim 1 ,
wherein the etching is wet etching, and
wherein the etching is performed by bringing an etching medium into contact with all surfaces of the chemically tempered glass.
6 . The method of manufacturing a tempered glass according to claim 5 ,
wherein the etching medium is an aqueous solution containing HF,
wherein the aqueous solution containing HF is
an aqueous solution containing only HF at a concentration of from 0.1 mol/L to 30 mol/L, or
an aqueous solution containing HF at a concentration of from 0.1 mol/L to 30 mol/L, and one substance selected from the group consisting of: HCl; HNO 3 ; H 2 SO 4 ; and NH 4 F, the one substance having a concentration of from 0.1 mol/L to 30 mol/L, and
wherein the etching is performed by immersing the chemically tempered glass in the aqueous solution having a temperature of from 10° C. to 30° C. for from 0.1 minute to 60 minutes.
7 . The method of manufacturing a tempered glass according to claim 5 , wherein the etching medium is an alkaline aqueous solution.
8 . The method of manufacturing a tempered glass according to claim 7 ,
wherein the alkaline aqueous solution is an aqueous solution containing NaOH or KOH as an alkali component, and
wherein the etching is performed by immersing the chemically tempered glass in the aqueous solution, which has a concentration of the alkali component of from 1 mol/L to 20 mol/L and a temperature of from 10° C. to 130° C., for from 0.5 minute to 120 minutes.
9 . The method of manufacturing a tempered glass according to claim 1 , wherein main surfaces of the chemically tempered glass before the etching are non-polished surfaces.