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, 1978
Filed:
Jul. 11, 1977
Samuel J Ciurca, Jr, Rochester, NY (US);
Carl F Kohrt, Pittsford, NY (US);
Eastman Kodak Company, Rochester, NY (US);
Abstract
Disclosed herein are aqueous and nonaqueous photographic bleaching solutions and radiation sensitive elements comprising a thiyl bleaching agent precursor having the formula ##STR1## wherein Z comprises the nonmetallic atoms necessary to complete a 5 to 7 member heterocyclic ring; R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are independently selected from the group consisting of alkyl, cycloalkyl, aralkyl, aryl or R.sup.2 and R.sup.3 or R.sup.4 and R.sup.5 can be taken together with the carbon atom of the ring to which they are attached to form a cycloalkyl or cycloalkenyl group; and R.sup.1 is independently selected from the group consisting of hydrogen, oxo and a complexing ligand for silver (I) ion wherein the Ksp of the complexed product of the ligand and silver (I) ion is less than about 10.sup.-12 at 25.degree. C. The thiyl bleaching agents disclosed herein are capable of bleaching preformed or predeveloped metals such as silver in both aqueous and nonaqueous photographic materials. They do not adversely affect the photographic properties of radiation sensitive emulsions and can be thermally activated in a dry photothermographic process.