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:
Mar. 20, 1979
Filed:
Mar. 01, 1978
Applicant:
Inventor:
Herbert Meissner, Braunau am Inn, AT;
Assignee:
Vereinigte Metallwerke Ranshofen-Berndorf Aktiengesellschaft, Braunau am Inn, AT;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C23F / ; C23F / ;
U.S. Cl.
CPC ...
148-627 ; 204 / ; 427160 ;
Abstract
To provide a substrate of aluminum with a dark surface layer of high absorption/emission ratio for luminous energy, the degreased and pickled substrate is immersed in a hot chromating bath until an oxide coating of not more than 2.5.mu. thickness is formed thereon. This coating is then colored black in a hot, acidic dyeing solution (pH between about 0.5 and 5) of potassium permanganate and a nitrate of cobalt or copper.