Surface nitrided alkali-free glasses

Patent metadata

Field	Value
Publication number	US-9695081-B2
Application number	US-201514710130-A
Country	US
Kind code	B2
Filing date	May 12, 2015
Priority date	May 15, 2014
Publication date	Jul 4, 2017
Grant date	Jul 4, 2017

Abstract

Alkali-free glasses are disclosed having (in weight %) 50≦SiO 2 ≦80%, 2≦Al 2 O 3 ≦17%, 8≦B 2 O 3 ≦36%, and greater than or equal to 2% and less than or equal to 25% of at least one of CaO, MgO, BaO, SrO or ZnO. The alkali-free glasses can have a surface layer with greater than 0.2 weight % N. Such alkali-free glasses are achieved by nitriding processes and exhibit increased strength, scratch resistance and chemical durability.

First claim

What is claimed is:

1. An article comprising an alkali-free glass composition comprising (in weight %) 50≦SiO 2 ≦80%, 2≦Al 2 O 3 ≦17%, 8≦B 2 O 3 ≦36%, and greater than or equal to 2% and less than or equal to 25% of at least one of CaO, MgO, BaO, SrO or ZnO, the alkali-free glass composition comprising a surface diffusion layer comprising greater than 0.2 weight % N, wherein the surface diffusion layer increases the Young's modulus of the article.

2. The article according to claim 1 wherein a summed amount of CaO, MgO, BaO, SrO and ZnO is in the range of 9-24 weight %.

3. The article according to claim 1 comprising a molar volume greater than 26 cm 3 /mole.

4. The article according to claim 1 comprising a molar volume greater than 27 cm 3 /mole.

5. The article according to claim 1 wherein the surface layer comprises a thickness of greater than 1 nm.

6. The article according to claim 1 wherein the surface layer comprises a thickness of greater than 10 nm.

7. The article according to claim 1 wherein the surface layer comprises a thickness of greater than 100 nm.

8. The article according to claim 1 wherein the surface layer comprises a thickness of greater than 1 micron.

9. The article according to claim 1 wherein the surface layer comprises a thickness of greater than 10 microns.

10. The article according to claim 1 wherein the surface layer comprises greater than 1 weight % N.

11. The article according to claim 1 wherein the surface layer comprises at least 2 weight % N.

12. The article according to claim 1 wherein the surface layer comprises at least 4 weight % N.

13. The article according to claim 1 wherein the surface layer comprises at least 8 weight % N.

14. The article according to claim 1 wherein the surface layer comprises at least 14 weight % N.

15. The article according to claim 1 comprising a glass sheet.

16. The article according to claim 1 comprising a 3D glass sheet.

17. The article according to claim 1 wherein the glass composition is tempered.

18. The article according to claim 1 , wherein the Young's modulus increases by at least about 17%.

19. The article according to claim 1 , wherein the Young's modulus is at least about 72.7 GPa.

20. The article of according to claim 19 , wherein the Young's modulus is in a range from about 72.7 GPa to about 137.7 GPa.

21. An article comprising an alkali-free glass composition comprising (in weight %) 65≦SiO 2 ≦75%, 7≦Al 2 O 3 ≦13%, 5≦B 2 O 3 ≦36%, 5≦CaO≦15%, 0≦BaO≦5%, 0≦MgO≦3% and 0≦SrO≦5%, the composition comprising a surface diffusion layer comprising greater than 0.2 weight % N, wherein the surface diffusion layer increases the Young's modulus of the article.

22. The article according to claim 21 wherein the surface layer comprises a thickness of greater than 1 nm.

23. The article according to claim 21 wherein the surface layer comprises a thickness of greater than 10 nm.

24. The article according to claim 21 wherein the surface layer comprises a thickness of greater than 100 nm.

25. The article according to claim 21 wherein the surface layer comprises a thickness of greater than 1 micron.

26. The article according to claim 21 wherein the surface layer comprises greater than 1 weight % N.

27. The article according to claim 21 wherein the surface layer comprises at least 2 weight % N.

28. The article according to claim 21 wherein the surface layer comprises at least 4 weight % N.

29. The article according to claim 21 wherein the surface layer comprises at least 8 weight % N.

30. The article according to claim 21 wherein the surface layer comprises at least 14 weight % N.

31. The article according to claim 21 , wherein the Young's modulus increases by at least about 17%.

32. The article according to claim 21 , wherein the Young's modulus is at least about 72.7 GPa.

33. The article of according to claim 32 , wherein the Young's modulus is in a range from about 72.7 GPa to about 137.7 GPa.

34. An article comprising an alkali-free glass composition comprising (in weight %) 40≦SiO 2 ≦70%, 0≦Al 2 O 3 ≦20%, 1≦P 2 O 5 ≦15, 0≦B 2 O 3 ≦25%, and greater than or equal to 0% and less than or equal to 25% of at least one of CaO, MgO, BaO, SrO or ZnO, the composition comprising a surface diffusion layer comprising greater than 0.2 weight % N, wherein the surface diffusion layer increases the Young's modulus of the article.

35. The article according to claim 34 wherein the surface layer comprises a thickness of greater than 1 nm.

36. The article according to claim 34 wherein the surface layer comprises greater than 1 weight % N.

37. The article according to claim 34 , wherein the Young's modulus increases by at least about 17%.

38. The article according to claim 34 , wherein the Young's modulus is at least about 72.7 GPa.

39. The article of according to claim 38 , wherein the Young's modulus is in a range from about 72.7 GPa to about 137.7 GPa.

Assignees

• Corning Inc

Inventors

• Bookbinder Andrea Weiss
• Bookbinder Dana Craig
• Gross Timothy Michael
• Tandon Pushkar

Classifications

• C03C21/007

  in gaseous phase · CPC title

• C03C3/111

  containing nitrogen · CPC title

• C03C3/091

  containing aluminium · CPC title

• C03C3/045 Primary

  Silicon oxycarbide, oxynitride or oxycarbonitride glasses · CPC title

• C03C23/007

  by thermal treatment · CPC title