Application of activated arylhydrazides to silver halide photography
AssigneeEastman Kodak Company
InventorsThomas C. Hess, Karl E. Wiegers
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Abstract
The use of sulfinic acid radical substituted arylhydrazides in producing images in silver halide photographic elements is disclosed. The sulfinic acid radical substituted arylhydrazide can be incorporated in photographic silver halide, emulsions, and photographic elements. The sulfinic acid radical substituent is capable of activating the arylhydrazides, particularly for use at a lower alkaline pH. In negative working surface latent image forming emulsions the sulfinic acid radical substituted arylhydrazides permit higher speed or contrast to be achieved. In direct positive internal latent image forming emulsions increased nucleation activity and reduced rereversal can be achieved.
Claims34
A radiation sensitive silver halide emulsion containing an arylhydrazide comprised of an acyl group linked to a ring carbon atom of an aryl group by a hydrazo moiety having one of its nitrogen atoms sulfinic acid radical substituted and a hydrogen atom bonded to the other of its nitrogen atoms, said sulfinic acid radical substituent being of the formula:
- ##STR25## where Ar.sup.1 is an aromatic group.
In a photographic element capable of producing a direct positive image comprised of a support, an emulsion comprised of a dispersing medium and internal latent image forming silver halide grains, and up to 10.sup.-2 mole per mole of silver of an arylhydrazide nucleating agent capable of selectively rendering unexposed silver halide grains developable in a surface developer comprised of an acyl group linked to a ring carbon atom of an aryl group by a hydrazo moiety,
- the improvement comprising said hydrazo moiety containing an activating sulfinic acid radical substituent of the formula:
- ##STR28## where Ar.sup.1 is an aryl group.
In a negative working photographic element capable of producing a high contrast silver image comprised of a support, a silver halide emulsion layer comprised of a dispersing medium and radiation sensitive silver halide grains capable of forming a surface latent image having a mean diameter of 0.7 micron or less, and in said emulsion layer or an adjacent hydrophilic colloid layer an arylhydrazide in a concentration of from 10.sup.-4 to 10.sup.-2 mole per mole of silver, said arylhydrazide having an acyl group linked to a ring carbon atom of an aryl group by a hydrazo moiety,
- the improvement comprising said hydrazo moiety containing an activating sulfinic acid radical substituent of the formula:
- ##STR31## where Ar.sup.1 is an aryl group.
In a negative working silver halide photographic element comprised of a support, an emulsion layer comprised of a dispersing medium, surface latent image forming silver halide grains, and adsorbed to the surface of said silver halide grains from 10.sup.-7 to 10.sup.-2 mole per mole of silver of an arylhydrazide comprised of a thioamide adsorption promoting moiety substituted aryl group linked directly at a ring carbon atom to a hydrazo group which in turn is directly linked to an acyl group,
- the improvement comprising said hydrazo moiety containing an activating sulfinic acid radical substituent of the formula:
- ##STR34## where Ar.sup.1 is an aryl group.
In a negative working silver halide photographic element comprised of a support, an emulsion layer comprised of a dispersing medium, surface latent image forming silver halide grains, and adsorbed to the surfaces of said silver halide grains from 10.sup.-7 to 10.sup.-2 mole per mole of silver of an arylhydrazide comprised of a thioamide adsorption promoting moiety substituted aryl group, an acyl group, and a divalent hydrazo moiety linking a ring carbon atom of said aryl to said acyl groups,
- the improvement in which said arylhydrazide is of the formula:
- ##STR35## wherein Acyl is an acyl group;
- D is phenylene;
- R.sup.1 is hydrogen;
- R.sup.2 is a sulfinic acid radical substituent;
- X is --0--, --S--, or --N(R.sup.6)--;
- and
- R.sup.4 and R.sup.6 are hydrogen, alkyl, haloalkyl, alkoxyalkyl, phenylalkyl, phenyl, naphthyl, alkylphenyl, cyanophenyl, halophenyl, or alkoxyphenyl, each alkyl moiety having up to about 18 carbon atoms.
A photographic element according to claim 33 in which said phenyl substituent is an alkylphenyl subsitutent in which said alkyl moiety contains from 1 to 3 carbon atoms.
A silver halide photographic light sensitive material comprising a layer containing a compound represented by the formula ##STR37## wherein Acyl represents an acyl group;
- Ph represents a substituted or unsubstituted phenyl group;
- and
- R.sup.2 represents a sulfinic acid radical of the formula:
- ##STR38## where Ar.sup.1 is an aryl group.
Dependencies are inferred from the claim text.