Scratch resistant glass and method of making

Patent metadata

Field	Value
Publication number	US-11034611-B2
Application number	US-201715585817-A
Country	US
Kind code	B2
Filing date	May 3, 2017
Priority date	May 20, 2014
Publication date	Jun 15, 2021
Grant date	Jun 15, 2021

Abstract

A scratch resistant alkali aluminoborosilicate glass. The glass is chemically strengthened and has a surface layer that is rich in silica with respect to the remainder of the glass article. The chemically strengthened glass is then treated with an aqueous solution of a mineral acid other than hydrofluoric acid, such as, for example, HCl, HNO 3 , H 2 SO 4 , or the like, to selective leach elements from the glass and leave behind a silica-rich surface layer. The silica-rich surface layer improves the Knoop scratch threshold of the ion exchanged glass compared to ion exchanged glass that are not treated with the acid solution as well as the post-scratch retained strength of the glass.

First claim

The invention claimed is:

1. A method of improving the scratch resistance of a glass, the method comprising:
a. treating a surface of the glass with an acid at a predetermined temperature for a predetermined time;
b. removing non-silica components from the surface; and
c. forming a porous silica-rich layer on the surface of the glass, wherein the silica-rich layer extends from the surface to a depth of greater than or equal to 100 nm to less than or equal to 600 nm into the glass.

2. The method of claim 1 , further comprising ion exchanging the glass prior to treating the surface with an acid.

3. The method of claim 2 , wherein the glass article has a compressive layer extending from the depth of the silica-rich layer to a depth of layer of greater than or equal to 20 μm, and wherein the compressive layer has a maximum compressive stress of greater than or equal to 300 MPa.

4. The method of claim 2 , wherein the glass article has a Knoop scratch initiation threshold of greater than or equal to 12 N.

5. The method of claim 2 , wherein the glass article has a Knoop scratch initiation threshold of greater than or equal to 16 N.

6. The method of claim 2 , wherein the glass article has a Knoop scratch initiation threshold of greater than or equal to 20 N to less than or equal to 60 N.

7. The method of claim 1 , wherein the glass article has a Vickers crack initiation threshold of greater than or equal to 5 kgf.

8. The method of claim 1 , wherein the glass article comprises an alkali aluminosilicate glass.

9. The method of claim 8 , wherein the glass article comprises an alkali aluminoborosilicate glass.

10. The method of claim 1 , wherein the glass comprises a borosilicate glass.

11. The method of claim 1 , wherein forming the porous silica-rich layer comprises treating the surface with at least one mineral acid other than hydrofluoric acid.

12. The method of claim 11 , wherein the at least one mineral acid comprises at least one of HCl, HNO 3 , and H 2 SO 4 .

13. The method of claim 11 , wherein the at least one mineral acid is present in a concentration of greater than or equal to 0.02 N.

14. The method of claim 13 , wherein the at least one mineral acid is present in a concentration in a range from 0.02N up to 60 N.

15. The method of claim 1 , wherein the predetermined temperature is in a range from 25° C. up to 95° C.

16. The method of claim 1 , wherein the predetermined time is in a range from 1 hour up to 24 hours.

Assignees

• Corning Inc

Inventors

• Gomez Sinue
• Morena Robert Michael
• Noni Jr Douglas Miles
• Price James Joseph
• Sick Sara Jean

Classifications

• C03C3/097

  containing phosphorus, niobium or tantalum · CPC title

• C03C2204/00

  Glasses, glazes or enamels with special properties · CPC title

• C03C11/005

  obtained by leaching after a phase separation step · CPC title

• C03C21/002

  to perform ion-exchange between alkali ions (C03C21/005 takes precedence) · CPC title

• C03C3/087

  containing calcium oxide, e.g. common sheet or container glass · CPC title