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:
Nov. 07, 1989
Filed:
Dec. 22, 1988
Applicant:
Inventor:
Richard L Helferich, Clayton, OH (US);
Assignee:
The Duriron Company, Inc., Dayton, OH (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C04B / ; C04B / ;
U.S. Cl.
CPC ...
106 75 ; 106 84 ; 501 84 ; 501 80 ;
Abstract
The alkali metal content of unfired porous ceramic shapes is substantially reduced by treatment with water to remove excess alkali and treatment with a dilute aqueous solution of an ammonium salt, preferably ammonium chloride, to exchange ammonium ion for remaining alkali metal ion, such that, upon firing, porous ceramic articles are produced having improved stability in high temperature and/or temperature-cycled environments.