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US 4,033,948 AGranted
Acutance agents for use in thermally-developable photosensitive compositions
AssigneeMinnesota Mining and Manufacturing Company
InventorHarvey A. Brown
Life of this patent
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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.
Claims3
A methine arylidene dye base 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.sup.1 is an aprotic electron-withdrawing group having a .sigma..sub.para value of 0.45 to 0.63 selected from CF.sub.3 and CN;
- T.sup.2 is NO.sub.2 ;
- and
- R.sup.2 and R.sup.3 are hydrogen or together constitute a condensed carbocyclic aromatic ring.
6 more elements
Dependencies are inferred from the claim text.