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:
Dec. 31, 1991
Filed:
Nov. 22, 1989
Applicant:
Inventors:
Gunter Frankfurter, Marktredwitz, DE;
Reinhard Manner, Maintal, DE;
Assignee:
Hoechst Aktiengesellschaft, Frankfurt am Main, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F16L / ;
U.S. Cl.
CPC ...
428 346 ; 138145 ; 428212 ; 428215 ; 4283073 ;
Abstract
A gas-tight aluminum oxide tube having an Al.sub.2 O.sub.3 content of 98.0 to 99.8 wt-%, wherein the interior of the tube has a coating of Al.sub.2 O.sub.3 with a thickness of from 0.03 to 0.30 mm and a mean roughness R.sub.a of 2 to 10 .mu.m, is provided. Preferably, the outer surface of the tube can have a mean roughness of 1.0 to 1.5 .mu.m. Also, the coating material can contain from 15 to 30 vol-% pores and the tube material can contain from 5 to 10 vol-% pores.