# US 10,766,811 B2 · Ion exchanged glass with high resistance to sharp contact failure and articles made therefrom

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- Number: US 10,766,811 B2
- Document ID: US10766811B2
- Status: Granted
- Kind: B2
- Application number: 16/402,638
- Filed: 2019-05-03
- Published: 2019-08-22
- Granted: 2020-09-08
- Earliest claimed: 2011-08-19
- Assignees: Corning Incorporated
- Applicants: Corning Incorporated
- Inventors: Timothy Michael Gross
- Web page: https://patentgrep.com/patent/US10766811B2

## CPC

- C03C 21/002: {to perform ion-exchange between alkali ions (C03C21/005 takes precedence)}
- C03C 3/091: containing aluminium
- C03C 3/097: containing phosphorus, niobium or tantalum
- C03C 10/0018: {containing SiO2, Al2O3 and monovalent metal oxide as main constituents}
- C03C: CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS

## Abstract

An article comprising an ion-exchanged glass material that prevents sharp contact flaws from entering a central region of the material that is under central tension and thus causing failure of the material. The glass material may be a glass or glass ceramic having a surface layer under compression. In some embodiments, the depth of the compressive layer is greater than about 75 μm. The greater depth of layer prevents flaws from penetrating the compressive layer to the region under tension.

## Claims

### Claim 1

An article comprising a glass material, the glass material having a thickness of less than about 1.5 mm, a compressive layer extending from a surface of the glass material to a depth of layer of at least 75 microns, an inner central region under a tension of up to about 75 MPa, and a Vickers crack initiation threshold of at least about 10 kgf, wherein the compressive layer is under a compressive stress of at least 250 MPa, wherein [(Al2O3 (mol %)+B2O3(mol %))/(Σ alkali metal modifiers (mol %))]>1.

### Claim 2 (depends on 1)

The article of claim 1, wherein the Vickers crack initiation threshold is at least about 20 kgf.

### Claim 3 (depends on 1)

The article of claim 1, wherein the glass material is strengthened by ion exchange.

### Claim 4 (depends on 1)

The article of claim 1, wherein the glass material is a glass ceramic comprising a silicate glassy phase and a ceramic phase.

### Claim 5 (depends on 4)

The article of claim 4, wherein the ceramic phase comprises at least one of β-spodumene, β-quartz, nepheline, kalsilite, carnegieite, and combinations thereof.

### Claim 6 (depends on 1)

The article of claim 1, wherein the glass material is an alkali aluminosilicate glass.

### Claim 7 (depends on 6)

The article of claim 6, wherein the alkali aluminosilicate glass comprising: from about 64 mol % to about 68 mol % SiO2; from about 12 mol % to about 16 mol % Na2O; from about 8 mol % to about 12 mol % Al2O3; from 0 mol % to about 3 mol % B2O3; from about 2 mol % to about 5 mol % K2O; from about 4 mol % to about 6 mol % MgO; and from 0 mol % to about 5 mol % CaO; wherein: 66 mol %≤SiO2+B2O3+CaO≤69 mol %; Na2O+K2O+B2O3+MgO+CaO+SrO>10 mol %; 5 mol %≤MgO+CaO+SrO≤8 mol %; (Na2O+B2O3)−Al2O3≤2 mol %; 2 mol %≤Na2O−Al2O3≤6 mol %; and 4 mol %≤(Na2O+K2O)−Al2O3≤10 mol %.

### Claim 8 (depends on 6)

The article of claim 6, wherein the alkali aluminosilicate glass comprises: from about 60 mol % to about 70 mol % SiO2; from about 6 mol % to about 14 mol % Al2O3; from 0 mol % to about 15 mol % B2O3; from 0 mol % to about 15 mol % Li2O; from 0 mol % to about 20 mol % Na2O; from 0 mol % to about 10 mol % K2O; from 0 mol % to about 8 mol % MgO; from 0 mol % to about 10 mol % CaO; from 0 mol % to about 5 mol % ZrO2; from 0 mol % to about 1 mol % SnO2; from 0 mol % to about 1 mol % CeO2; less than about 50 ppm As2O3; and less than about 50 ppm Sb2O3; wherein 12 mol %≤Li2O+Na2O+K2O≤20 mol % and 0 mol %≤MgO+CaO≤10 mol %.

### Claim 9 (depends on 6)

The article of claim 6, wherein the alkali aluminosilicate glass comprises: from 50 mol % to about 72 mol % SiO2; from about 9 mol % to about 17 mol % Al2O3; from about 2 mol % to about 12 mol % B2O3; from about 8 mol % to about 16 mol % Na2O; and from 0 mol % to about 4 mol % K2O.

### Claim 10 (depends on 6)

The article of claim 6, wherein the alkali aluminosilicate glass comprises SiO2, Al2O3, P2O5, and at least one alkali metal oxide (R2O), wherein 0.75≤[(P2O5(mol %)+R2O(mol %))/M2O3 (mol %)]≤1.3, where M2O3=Al2O3+B2O3.

### Claim 11 (depends on 6)

The article of claim 6, wherein the alkali aluminosilicate glass comprises at least 5 mol % P2O5, wherein (M2O3(mol %)/RxO(mol %))<1, wherein M2O3=Al2O3+B2O3, and wherein RxO is the sum of monovalent and divalent cation oxides present in the alkali aluminosilicate glass.

### Claim 12 (depends on 11)

The article of claim 11, wherein the monovalent and divalent cation oxides are selected from the group consisting of Li2O, Na2O, K2O, Rb2O, Cs2O, MgO, CaO, SrO, BaO, and ZnO.

### Claim 13 (depends on 12)

The article of claim 12, wherein the alkali aluminosilicate glass comprises 0 mol % B2O3.

### Claim 14 (depends on 6)

The article of claim 6, wherein the alkali aluminosilicate glass comprises at least about 50 mol % SiO2 and at least about 11 mol % Na2O.

### Claim 15 (depends on 6)

The article of claim 6, wherein the alkali aluminosilicate glass has a liquidus viscosity of at least about 130 kilopoise.

### Claim 16 (depends on 1)

The article of claim 1, wherein the compressive stress is at least about 900 MPa.

### Claim 17 (depends on 1)

The article of claim 1, wherein the glass material contains 0 mol % of oxides of at least one of lithium, boron, barium, strontium, bismuth, antimony, and arsenic.

### Claim 18 (depends on 1)

The article of claim 1, wherein the glass material forms at least a portion of a viewing window, a touch screen, or an external housing for an electronic device.