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. 11, 1988
Filed:
May. 26, 1987
Helmut Offenbacher, Graz, AT;
Herbert Kroneis, Graz, AT;
AVL AG, Schaffhausen, CH;
Abstract
Bodies of borosilicate glass with a B.sub.2 O.sub.3 content of less than 13 percent by weight are provided with a microporous layer of a thickness of 5 to 20 .mu.m, and are thus turned into carriers for optical sensors. This process is characterized by the following steps. Thermal decomposition for 5 to 10 days at 500.degree. to 560.degree. C.; removal of the topmost layer of glass to a depth of at least 10 .mu.m in the part of the surface to be rendered porous; leaching of the separated borate phase with diluted mineral acids for a minimum of 2 days at 70.degree. to 98.degree. C.; and after-treatment of the microporous layer, including (a) chemical treatment with concentrated sulphuric acid and concentrated nitric acid for 2 hours at 20.degree. C., and (b) heat-treatment for 10 minutes to 2 hours at 450.degree. to 700.degree. C.