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:
Aug. 22, 1978
Filed:
Dec. 16, 1976
Applicant:
Inventors:
Yoshiyuki Asahara, Higashiyamato, JP;
Tetsuro Izumitani, Hino, JP;
Assignee:
Hoya Glass Works, Ltd., Tokyo, JA;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C03C / ; C03B / ; C03C / ;
U.S. Cl.
CPC ...
65 3 / ; 65 33 ; 65 37 ; 65 6 / ; 65 61 ; 106 52 ; 350205 ; 350319 ;
Abstract
A process for producing a soft aperture filter having high acid and heat resistance as well as a desired colored layer thickness comprising heat-treating a glass, having a base composition of 55 to 72 mole percent SiO.sub.2, 15 to 35 mole percent Na.sub.2 O, 0 to 5 percent di-valent oxides other than ZnO, 4 to 15 mole percent ZnO, and 0 to 5 mole percent Al.sub.2 O.sub.3 with Sb.sub.2 O.sub.3 and/or As.sub.2 O.sub.3 additionally present in an amount of 2 to 5 weight percent of the base composition, in a fused bath containing 14 to 60 mole percent of a silver salt, and optionally with NaNO.sub.3 and/or Na.sub.2 SO.sub.4.