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:
Feb. 17, 2009
Filed:
Jun. 07, 2002
Karin Naumann, Ober-Olm, DE;
Christof Kass, Tischenreuth, DE;
Franz Ott, Mitterteich, DE;
Schott AG, Mainz, DE;
Abstract
The process of producing a refined borosilicate glass includes preparing a glass batch with a composition in wt. % on the basis of oxide content of SiO65-82; AlO, 2-8; BO, 5-13; MgO+CaO+SrO +BaO+ZnO, 0-7; ZrO, 0-2; and LiO+NaO+KO, 3-10; adding 0.05 wt. % to 0.6 wt. % of sulfate(s) expressed as SOto the glass batch as the refining agent; melting the glass batch including the refining agent to form melted glass; and then hot-shaping the borosilicate glass. The refining agent may also include from 0.01 wt. % to 0.6 wt. % of For from 0.015 wt. % to 0.6 wt. of Cl. The sulfate is preferably an alkali metal and/or alkaline earth metal sulfate or sulfates.