Methods for treating glass articles

Patent metadata

Field	Value
Publication number	US-10669196-B2
Application number	US-201515541238-A
Country	US
Kind code	B2
Filing date	Dec 30, 2015
Priority date	Dec 31, 2014
Publication date	Jun 2, 2020
Grant date	Jun 2, 2020

Abstract

Methods for increasing the hydrolytic resistance of a glass article are disclosed. According to one embodiment, the method includes providing a glass article with a pre-treatment hydrolytic titration value. Thereafter, the glass article is thermally treated at a treatment temperature greater than a temperature 200 C less than a strain temperature of the glass article for a treatment time greater than or equal to about 0.25 hours such that, after thermally treating the glass article, the glass article has a post-treatment hydrolytic titration value that is less than the pre-treatment hydrolytic titration value.

First claim

The invention claimed is:

1. A method for increasing the hydrolytic resistance of a glass article, the method comprising:
providing a glass article with a pre-treatment hydrolytic titration value and comprising a glass surface layer having inorganic deposits; and
thermally treating the glass article at a treatment temperature at least 20° C. greater than the annealing temperature of the glass article and less than a softening point of the glass article for a treatment time greater than or equal to about 0.25 hours such that species forming the inorganic deposits of the glass surface layer diffuse into the glass and, after thermally treating the glass article, the glass article has a post-treatment hydrolytic titration value that is less than the pre-treatment hydrolytic titration value.

2. The method of claim 1 , wherein:
prior to thermally treating, the surface of the glass article with the glass surface layer has a persistent layer heterogeneity relative to a midpoint within a thickness of the glass article, wherein an extrema in a layer concentration of each constituent component in the glass surface layer is less than about 80% or greater than about 120% of a concentration of a same constituent component at the midpoint prior to thermally treating; and
after thermally treating, an extrema in the layer concentration of each constituent component in the glass surface layer is greater than or equal to 80% or less than or equal to about 120% of the concentration of the same constituent component at the midpoint after thermally treating.

3. The method of claim 2 , wherein after thermally treating an extrema in the layer concentration of each constituent component in the glass surface layer is greater than or equal to 92% or less than or equal to about 108% of the concentration of the same constituent component at the midpoint.

4. The method of claim 1 , wherein a surface of the glass article comprises a surface region extending over the surface of the glass article to a depth from about 10 nm to about 50 nm from the surface of the glass article; and
for a discrete point on the surface of the glass article, an extrema of a surface concentration of each constituent component of the glass article in the surface region at the discrete point is greater than or equal to about 70% and less than or equal to about 130% of a same constituent component in the surface region at any second discrete point on the surface of the glass article after thermally treating.

5. The method of claim 1 , wherein the treatment time is greater than or equal to about 1 hour.

6. The method of claim 1 , wherein the glass article is formed from an alkali aluminosilicate glass.

7. The method of claim 1 , wherein the glass article is formed from a borosilicate glass.

8. The method of claim 1 , wherein the glass article is formed from a Type I, Class A or a Type I, Class B glass according to ASTM Standard E438-92.

9. The method of claim 1 , wherein the glass article has a Type I hydrolytic resistance under USP <660> after the thermal treating.

10. The method of claim 1 wherein the glass article is a pharmaceutical container.

11. A method for increasing the hydrolytic resistance of a glass article, the method comprising:
providing a glass article with at least one surface having a glass surface layer with a composition that is different than a composition at a midpoint of a thickness of the glass article, the at least one surface having a pre-treatment hydrolytic titration value; and
diffusing species from the glass surface layer into the thickness of the glass article to homogenize the surface glass layer relative to the midpoint of the thickness of the glass article such that, after diffusing, the at least one surface of the glass article has a post-treatment hydrolytic titration value which is less than the pre-treatment hydrolytic titration value, wherein diffusing species within the surface glass layer comprises thermally treating the glass article at a temperature at least 20° C. greater than an annealing temperature of the glass article and less than a softening point of the glass article.

12. The method of claim 11 , wherein the glass article is thermally treated for at least 0.25 hours.

13. The method of claim 11 , wherein the glass article is thermally treated for at least 1 hour.

14. The method of claim 11 , wherein:
prior to diffusing the species, the glass surface layer has a persistent layer heterogeneity relative to the midpoint of the thickness of the glass article, wherein an extrema in a layer concentration of each constituent component in the glass surface layer is less than about 80% or greater than about 120% of a bulk concentration of a same constituent component at the midpoint; and
after diffusing the species, an extrema in the layer concentration of each constituent component in the glass surface layer is greater than or equal to 80% or less than or equal to about 120% of a concentration of the same constituent component at the midpoint.

15. The method of 14 , wherein after diffusing the species an extrema in the layer concentration of each constituent component in the glass surface layer is greater than or equal to 92% or less than or equal to about 108% of a concentration of the same constituent component at the midpoint.

16. The method of claim 11 , wherein the at least one surface of the glass article comprises a surface region extending over the at least one surface of the glass article to a depth from about 10 nm to about 50 nm from the at least one surface of the glass article; and
for a discrete point on the at least one surface of the glass article, an extrema of a surface concentration of each constituent component of the glass article in the surface region at the discrete point is greater than or equal to about 70% and less than or equal to about 130% of a same constituent component in the surface region at any second discrete point on the at least one surface of the glass article after diffusing the species.

17. The method of claim 11 wherein the glass article is a pharmaceutical container.

Assignees

• Corning Inc

Inventors

• Gaylo Keith Raymond
• Klingensmith Lewis Kirk
• Schaut Robert Anthony
• Tietje Steven Alvin

Classifications

• G01N31/166

  Continuous titration of flowing liquids · CPC title

• A61J1/065

  Rigid ampoules, e.g. glass ampoules · CPC title

• C03B29/025

  Glass sheets · CPC title

• C03C23/007 Primary

  by thermal treatment · CPC title

• C03B25/025

  Glass sheets · CPC title