Ion exchangeable glass with high crack initiation threshold
AssigneeCorning Incorporated
InventorTimothy Michael Gross
Life of this patent
Estimating the term…
Abstract
Alkali aluminosilicate glasses that are resistant to damage due to sharp impact and capable of fast ion exchange are provided. The glasses comprise at least 4 mol % P2O5 and, when ion exchanged, have a Vickers indentation crack initiation load of at least about 7 kgf.
Claims26
An alkali aluminosilicate glass comprising at least about 4 mol % P2O5 and from 0 mol % to about 4 mol % B2O3, wherein the alkali aluminosilicate glass is lithium-free and ion exchanged to a depth of layer of at least about 10 μm, and wherein:
- i. 1.3<[(P2O5+R2O)/M2O3]≦2.3;
- where M2O3=Al2O3+B2O3, and R2O is the sum of monovalent cation oxides present in the alkali aluminosilicate glass.
A method of forming an ion-exchanged alkali aluminosilicate glass, the method comprising:
- a. providing a non-ion exchanged alkali aluminosilicate precursor glass comprising at least about 4 mol % P2O5 and from 0 mol % to about 4 mol % B2O3, wherein the precursor glass is lithium-free and wherein 1.3<[P2O5+R2O)/M2O3]≦2.3, where M2O3=Al2O3+B2O3, and R2O is the sum of monovalent cation oxides present in the precursor glass, and
- b. immersing the precursor glass in an ion exchange bath for a time period of up to about 24 hours to form an ion-exchanged alkali aluminosilicate glass having a compressive layer extending from a surface of the ion-exchanged alkali aluminosilicate glass to a depth of layer of at least 10 μm.
An alkali aluminosilicate glass consisting essentially of from about 40 mol % to about 70 mol % SiO2;
- from about 11 mol % to about 25 mol % Al2O3;
- from about 4 mol % to about 15 mol % P2O5;
- from about 13 mol % to about 25 mol % Na2O;
- from about 13 to about 30 mol % RxO;
- from about 11 to about 30 mol % M2O3;
- from 0 mol % to about 1 mol % K2O;
- from 0 mol % to about 4 mol % B2O3, and 3 mol % or less of one or more of TiO2, MnO, Nb2Os, MoO3, Ta2O5, WO3, ZrO2, Y2O3, La2O3, HfO2, CdO, SnO2, Fe2O3, CeO2, As2O3, Sb2O3, Cl, and Br;
- wherein
- i. RxO is the sum of the alkali metal oxides, alkaline earth metal oxides, and transition metal monoxides present in the glass,
- ii. the glass is lithium-free;
- iii. the glass is ion exchanged to a depth of layer of at least about 10 μm, and
- iv. 1.3<[(P2O5+R2O)/M2O3]≦2.3;
- where M2O3=Al2O3+B2O3, and R2O is the sum of monovalent cation oxides present in the glass.
Dependencies are inferred from the claim text.