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:
Apr. 21, 1998
Filed:
Oct. 23, 1996
David Alan Wilson, Richwood, TX (US);
Druce Kirk Crump, Lake Jackson, TX (US);
The Dow Chemical Company, Midland, MI (US);
Abstract
Polyamino disuccinic acids are effective chelants for use in photography and gas conditioning (both applications preferably involving the polyamino disuccinic acid in the form of a metal, preferably an iron complex). The copper chelates are also useful in electroless copper plating. In photography, the invention includes a method of bleaching or bleach-fixing a photographic material which comprises contacting said material with a bleaching solution containing a bleaching agent comprising a ferric complex of a polyamino disuccinic acid and the solution so used. In electroless deposition, the invention includes a method of electroless deposition of copper upon a non-metallic surface receptive to the deposited copper including a step of contacting the non-metallic surface with an aqueous solution comprising a soluble copper salt and a polyamino disuccinic acid and plating baths appropriate for such use. Another aspect of the invention includes a method for removing iron oxide deposits from a surface including a step of contacting the deposits with a solution comprising an ammoniated polyamino disuccinic acid. Yet another aspect of the invention involves gas conditioning including a process of removing H.sub.2 S from a fluid comprising contacting said fluid with an aqueous solution at a pH suitable for removing H.sub.2 S wherein said solution contains at least one higher valence polyvalent metal chelate of a polyamino disuccinic acid and a process of removing NO.sub.x from a fluid comprising contacting the fluid with an aqueous solution of at least one lower valence state polyvalent metal chelate of a polyamino disuccinic acid.