The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 07, 1997
Filed:
Dec. 15, 1995
Applicant:
Inventor:
Roger J Araujo, Horseheads, NY (US);
Assignee:
Corning Incorporated, Corning, NY (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C03C / ; C03C / ; C03C / ;
U.S. Cl.
CPC ...
501 66 ; 65 3014 ; 501 52 ; 501 77 ;
Abstract
A method of strengthening a glass article by developing compressive stress in a surface layer on the article through an exchange of alkali metal ions in the surface layer at an elevated temperature below the glass strain point, the step of minimizing stress relaxation by carrying out the ion exchange in a glass essentially free from non-bridging oxygen atoms. Glasses having particular utility contain alumina in their compositions in such amount that the number of aluminum atoms in a glass are at least equal to the number of alkali metal ions, or contain both alumina and boric oxide in such amounts that the formula ##EQU1## is satisfied.