Hydroxamic acid compounds as contrast enhancers for black-and-white photothermographic and thermographic elements
AssigneeMinnesota Mining and Manufacturing Company
InventorsSharon M. Simpson, Francis H. Sansbury
Life of this patent
Estimating the term…
Abstract
Hydroxamic acid 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.
Claims35
A black-and-white 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 said non-photosensitive, reducible silver source;
- and
- (d) a binder;
- wherein said reducing agent system consists essentially of:
- (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 up to 20 carbon atoms;
- alkoxy, alkylthio, or amido groups of up to 20 carbon atoms;
- aryl, alkaryl, or aralkyl groups of up to 20 carbon atoms;
- aryloxy, arylthio, or anilino groups of up to 20 carbon atoms;
- aliphatic or aromatic heterocyclic ring groups containing up to 6 ring atoms;
- carbocyclic ring groups of up to 6 ring carbon atoms;
- and R.sup.2 represents a trityl group;
- and
- (iii) at least one hydroxamic acid compound having the formula:
- ##STR12## wherein:
- R.sup.3 represents alkyl or alkenyl groups of up to 20 carbon atoms;
- alkoxy, alkylthio, or amido groups of up to 20 carbon atoms;
- aryl, alkaryl, or aralkyl groups of up to 20 carbon atoms;
- aryloxy, arylthio, or anilino groups of up to 20 carbon atoms;
- aliphatic or aromatic heterocyclic ring groups containing up to 6 ring atoms;
- carbocyclic ring groups of up to 6 ring carbon atoms;
- and
- R.sup.4 represents hydrogen, alkyl or alkenyl groups of up to 20 carbon atoms;
- alkoxy, alkylthio, or amido groups of up to 20 carbon atoms;
- aryl, alkaryl, or aralkyl groups of up to 20 carbon atoms;
- aryloxy, arylthio, or anilino groups of up to 20 carbon atoms;
- aliphatic or aromatic heterocyclic ring groups containing up to 6 ring atoms;
- carbocyclic ring groups of up to 6 ring carbon atoms.
A black-and-white 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 said non-photosensitive, reducible silver source;
- and
- (c) a binder;
- wherein said reducing agent system consists essentially of:
- (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.2 represents hydrogen, alkyl or alkenyl groups of up to 20 carbon atoms;
- alkoxy, alkylthio, or amido groups of up to 20 carbon atoms;
- aryl, alkaryl, or aralkyl groups of up to 20 carbon atoms;
- aryloxy, arylthio, or anilino groups of up to 20 carbon atoms;
- aliphatic or aromatic heterocyclic ring groups containing up to 6 ring atoms;
- carbocyclic ring groups of up to 6 ring carbon atoms;
- and R.sup.2 represents a trityl group;
- and
- (iii) at least one hydroxamic acid compound having the formula:
- ##STR13## wherein:
- R.sup.3 represents alkyl or alkenyl groups of up to 20 carbon atoms;
- alkoxy, alkylthio, or amido groups of up to 20 carbon atoms;
- aryl, alkaryl, or aralkyl groups of up to 20 carbon atoms;
- aryloxy, arylthio, or anilino groups of up to 20 carbon atoms;
- aliphatic or aromatic heterocyclic ring groups containing up to 6 ring atoms;
- carbocyclic ring groups of up to 6 ring carbon atoms;
- and
- R.sup.4 represents hydrogen, alkyl or alkenyl groups of up to 20 carbon atoms;
- alkoxy, alkylthio, or amido groups of up to 20 carbon atoms;
- aryl, alkaryl, or aralkyl groups of up to 20 carbon atoms;
- aryloxy, arylthio, or anilino groups of up to 20 carbon atoms;
- aliphatic or aromatic heterocyclic ring groups containing up to 6 ring atoms;
- carbocyclic ring groups of up to 6 ring carbon atoms.
Dependencies are inferred from the claim text.