Acutance agents for use in thermally-developable photosensitive compositions
AssigneeMinnesota Mining and Manufacturing Company
InventorsHarvey A. Brown, Jack E. Reece
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Abstract
Certain members of the class of odd-numbered methine arylidene dye bases are found to be of use in thermally-developable photosensitive compositions and thermally-developable photosensitive elements containing such agents. These compounds are acutance agents which are relatively stable against photo-bleaching but undergo thermochemical bleaching on heating in silver salt-containing thermally-developable photosensitive compositions.
Claims5
In a photosensitive, heat-developable, dry silver sheet material containing an image forming system including in one layer a photosensitive silver halide catalyst-forming means and, as heat image-forming means, an organic silver compound, said image-forming system further including toner and a reducing agent the oxidation-reduction reaction of which latter with said organic silver compound being catalyzed by silver halide catalyst;
- the improvement characterized by the inclusion in said layer with said organic silver compound of an acutance agent represented by the formula ##STR10## wherein:
- Z represents the atoms necessary to complete a mono-or polycyclic dihydroheterocyclic nucleus having 5 to 6 atoms in the ring including the N of the formula;
- R.sup.1 is an alkyl, substituted alkyl, alkenyl or aryl group;
- m = 0 or 1;
- k = 0, 1 or 2;
- T is an aprotic electron-withdrawing group having a .sigma..sub.para value of 0.45 to 0.63 selected from CF.sub.3 or CN and R.sup.2 and R.sup.3 are hydrogen or together constitute a condensed carbocyclic aromatic ring.
Dependencies are inferred from the claim text.