N-acyl-hydrazine compounds as contrast enhancers for black-and-white photothermographic and thermographic elements
AssigneeMinnesota Mining and Manufacturing Company
InventorsSharon M. Simpson, Lori S. Harring
Life of this patent
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Abstract
N-acyl-hydrazine compounds are useful as contrast enhancers when used in combination with (i) hindered phenol developers, and (ii) trityl hydrazide and/or formyl-phenyl hydrazine co-developers, to produce ultra-high contrast black-and-white photothermographic and thermographic elements. The photothermographic and thermographic elements may be used as a photomask in a process where there is a subsequent exposure of an ultraviolet or short wavelength visible radiation-sensitive imageable medium.
Claims19
A photothermographic element comprising a support bearing at least one photosensitive, image-forming, photothermographic emulsion layer comprising:
- (a) a photosensitive silver halide;
- (b) a non-photosensitive, reducible silver source;
- (c) a reducing agent system for silver ion;
- and
- (d) a binder;
- wherein said reducing agent system comprises:
- (i) at least one hindered phenol;
- (ii) at least one co-developer of the formula
- R.sup.1 --(C.dbd.O)--NHNH--R.sup.2
- wherein:
- R.sup.1 represents hydrogen and R.sup.2 represents an aryl or substituted aryl group;
- or,
- R.sup.1 represents hydrogen, alkyl, or alkenyl groups of 1 to 20 carbon atoms;
- alkoxy, thioalkoxy, or amido groups of 1 to 20 carbon atoms;
- aryl, alkaryl, or aralkyl groups of up to 20 carbon atoms;
- aryloxy, thioaryloxy, or anilino groups of up to 20 carbon atoms;
- aliphatic or aromatic heterocyclic ring groups containing up to 6 ring atoms;
- carbocyclic ring groups comprising up to 6 ring carbon atoms;
- or fused ring or bridging groups comprising up to 14 ring atoms;
- and R.sup.2 represents a trityl group;
- and
- (iii) at least one N-acyl-hydrazine compound of the formula ##STR11## wherein:
- R.sup.3 represents an alkyl or alkenyl groups of 1 to 20 carbon atoms;
- alkoxy, thioalkoxy, or amido groups of up to 20 carbons;
- aryl, alkaryl or aralkyl groups comprising up to 20 carbon atoms;
- aryloxy, thioaryloxy, or anilino groups of up to 20 carbon atoms;
- aliphatic or aromatic heterocyclic ring groups containing up to 6 ring atoms;
- carbocyclic ring groups comprising up to 6 ring carbon atoms;
- or fused ring or bridging groups comprising up to 14 ring atoms.
A thermographic element comprising a support bearing at least one, image-forming, thermographic emulsion layer comprising:
- (a) a non-photosensitive, reducible silver source;
- (b) a reducing agent system for silver ion;
- and
- (c) a binder;
- wherein said reducing agent system comprises:
- (i) at least one hindered phenol;
- (ii) at least one co-developer of the formula
- R.sup.1 --(C.dbd.O)--NHNH--R.sup.2
- wherein:
- R.sup.1 represents hydrogen and R.sup.2 represents an aryl group;
- or,
- R.sup.1 represents hydrogen, alkyl or alkenyl groups of 1 to 20 carbon atoms;
- alkoxy, thioalkoxy, or amido groups of 1 to 20 carbon atoms;
- aryl, alkaryl, or aralkyl groups of up to 20 carbon atoms;
- aryloxy, thioaryloxy, or anilino groups of up to 20 carbon atoms;
- aliphatic or aromatic heterocyclic ring groups containing up to 6 ring atoms;
- carbocyclic ring groups comprising up to 6 ring carbon atoms;
- or fused ring or bridging groups comprising up to 14 ring atoms;
- and R.sup.2 represents a trityl group;
- and
- (iii) at least one N-acyl-hydrazine compound of the formula ##STR12## wherein R.sup.3 represents an alkyl or alkenyl groups of 1 to 20 carbon atoms;
- alkoxy, thioalkoxy, or amido groups of 1 to 20 carbons;
- aryl, alkaryl or aralkyl groups comprising up to 20 carbon atoms;
- aryloxy, thioaryloxy, or anilino groups of up to 20 carbon atoms;
- aliphatic or aromatic heterocyclic ring groups containing up to 6 ring atoms;
- carbocyclic ring groups comprising up to 6 ring carbon atoms;
- or fused ring or bridging groups comprising up to 14 ring atoms.
The thermographic element according to claim 16 wherein said binder is hydrophobic.
Dependencies are inferred from the claim text.