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. 02, 1999
Filed:
Mar. 11, 1997
Stephan Moritz, Erlensee, DE;
Wolfgang Englisch, Kelkheim, DE;
Heraeus Quarzglas GmbH, Hanau, DE;
Abstract
A shaped body of amorphous silicon dioxide, which has a chemical purity of at least 99.9% and a cristobalite content of at most 1% and which is impermeable to gas, is known. To provide shaped bodies of amorphous silicon dioxide which have a high precision, which can be small or large in size and of simple to complicated shape, which have a chemical purity of at least 99.9%, are impermeable to gas above wall thicknesses of 1 mm, which have a high cold flexural strength, low thermal conductivity and low radiation of heat, which are thermal shock resistant and can be exposed repeatedly or also long-term to temperatures in the range from 1000.degree. to 1300.degree. C. and which can be welded in a sharply delineated manner without spreading joins and which have a low spectral transmission from the ultraviolet to the middle infrared spectral region, the shaped body is opaque, contains pores, at a wall thickness of 1 mm has a direct spectral transmission which is virtually constant in the wavelength range from .lambda.=190 nm to .lambda.=2650 nm and is below 10%, and it has a density which is at least 2.15 g/cm.sup.3. A process for producing such shaped bodies is also provided.