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. 19, 1993
Filed:
Jul. 21, 1992
Piet Kok, Gent, BE;
Jean-Marie O Dewanckele, Drongen, BE;
Agfa-Gevaert, N.V., Mortsel, BE;
Abstract
A photographic direct positive material is disclosed comprising a support and one or more radiation sensitive emulsion layers containing internal latent image-forming silver halide grains characterized in that at least one of said emulsion layers further contains a masked stabilizer corresponding to general formula (I): ##STR1## wherein Z represents a lower alkyl group, a nitro group or a halogen atom, n=0 to 4, and M represents a positive counterion. Preferred compounds are 1-(2-sulphonatobenzoyl)-5-methyl-benzotriazole, 1-(2-sulphonatobenzoyl)-6-methyl-benzotriazole or a mixture of both. The masked stabilizer is preferably incorporated in the emulsion layer(s). The material preferably further contains a nucleating agent. Improved direct positive sensitometric properties and wider exposure latitude before encountering rereversal are obtained.