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. 05, 1993
Filed:
Oct. 30, 1992
Nobuo Nakano, Tokyo, JP;
Akihiro Yamamoto, Tokyo, JP;
Riken Keiki Co., Ltd., Tokyo, JP;
Abstract
A tape for detecting the presence of hydride gases by taking advantage of coloring reactions whose light sensitivity is lowered to a minimum without impairing the inherent mechanical strength of the reagent holder. The detection tape is prepared by impregnating a tape of porous cellulose fibers containing a gas adsorbent such as a powder of silica and a moisture keeper of glycerin with a coloring reagent of silver perchlorate or silver para-toluenesulfonate and a light resistance enhancer of para-toluenesulfonic acid. When the detection tape is exposed to a hydride gas contained in the sampled gas, silver perchlorate or silver para-toluenesulfonate is reduced by the hydride gas to form a colloid of silver that remains as a trace of reaction. As the amount of the colloid of silver is proportional to the concentration of the gas, the concentration of hydride gas can be determined by measuring the optical density of the trace of reaction. This tape does not discolor even after long storage as the light sensitivity of silver perchlorate and silver para-toluenesulfonate used as the coloring reagent is much lower than that of silver nitrate that has been used as the coloring reagent on the conventional detection tapes. Besides, the mechanical strength of the detection tape remains unimpaired because the acidity of para-toluenesulfonic acid added as the light resistance enhancer is not so strong as to damage the cellulose.