US 11,834,370 B2
Colored glass articles having improved mechanical durability
Xiaoju Guo, Pittsford, NY (US); Karl William Koch, III, Elmira, NY (US); Liping Xiong Smith, Painted Post, NY (US); and Nicole Taylor Wiles, Horseheads, NY (US)
Assigned to Corning Incorporated, Corning, NY (US)
Filed by CORNING INCORPORATED, Corning, NY (US)
Filed on Jan. 4, 2023, as Appl. No. 18/093,090.
Application 18/093,090 is a continuation of application No. 17/843,096, filed on Jun. 17, 2022.
Claims priority of provisional application 63/318,553, filed on Mar. 10, 2022.
Claims priority of provisional application 63/212,179, filed on Jun. 18, 2021.
Claims priority of provisional application 63/347,095, filed on May 31, 2022.
Claims priority of provisional application 63/347,201, filed on May 31, 2022.
Prior Publication US 2023/0192532 A1, Jun. 22, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. C03C 4/02 (2006.01); C03C 3/091 (2006.01); C03C 3/095 (2006.01); C03C 3/093 (2006.01); C03C 21/00 (2006.01)
CPC C03C 4/02 (2013.01) [C03C 3/091 (2013.01); C03C 3/093 (2013.01); C03C 3/095 (2013.01); C03C 21/002 (2013.01); C03C 2204/00 (2013.01)] 24 Claims
OG exemplary drawing
 
1. A colored glass back cover for an electronic device, comprising:
B2O3, Al2O3, Li2O, Na2O, K2O, MgO, and CaO in mol % amounts such that (3.802946+0.01747*B2O3+0.058769*Al2O3+0.080876*Li2O+0.148433*Na2O+0.153264*K2O+0.045179*MgO+0.080113*CaO) is less than or equal to 6.8 and greater than or equal to 5.7, and wherein a sum of (R2O+R′O) in mol % is less than or equal to 25 mol %, where R2O is a sum of alkali metal oxides Li2O, Na2O, and K2O in mol % of the glass of the colored glass back cover and R′O is a sum of ZnO and alkaline earth metal oxides CaO and MgO in mol %, thereby facilitating dielectric properties for use of the colored glass back cover in high frequency applications;
wherein the Al2O3 is greater than or equal to 10 mol % and less than or equal to 20 mol %, and a difference of (R2O−Al2O3) in mol % is greater than or equal to −8 mol % and less than or equal to 4 mol %, thereby controlling formation of non-bridging oxygen, wherein KIC fracture toughness of the glass of the colored glass back cover as measured by a chevron notch short bar method is greater than or equal to 0.7 MPa·m1/2;
wherein the glass of the colored glass back cover further comprises transition metal oxides and/or rare earth oxides colorants of NiO, Co3O4, Cr2O3, CuO, CeO2, TiO2 and/or combinations thereof such that a sum of (NiO+Co3O4+Cr2O3+CuO+CeO2+TiO2) in mol % is greater than or equal to 0.001 mol % and less than or equal to 10 mol %, and the glass of the colored glass back cover falls within a CIELAB color space, as measured at an article thickness of 1.33 mm under F2 illumination and a 10° standard observer angle, of L* greater than or equal to 65 and less than or equal to 98, absolute value of a* greater than or equal to 0.3, and absolute value of b* greater than or equal to 0.5; and
wherein the Na2O of the glass of the colored glass back cover is greater than 0 mol % and less than or equal to 8 mol %, and the K2O is greater than 0 mol % and less than or equal to 1 mol %, thereby facilitating ion-exchange, wherein the colored glass back cover has a depth of compression of 10 μm or greater, a surface compressive stress greater than or equal to 300 MPa, and a central tension greater than or equal to 40 MPa.