Imagewise hardening with inert transition metal complex oxidizing agents

Claim 2

In a process of imagewise-hardening at least one layer of a photographic element which contains a crosslinkable colloid, the improvement comprising reacting an inert transition metal ion complex oxidizing agent having a coordination number of 6 and which is capable of existing in at least two valence states with a reducing agent in the presence of a catalytic metal material or catalytic activated carbon material in a processing solution which is substantially free of silver halide solvents, wherein said catalytic material is provided in an imagewise distribution and wherein said oxidizing agent and said reducing agent are chosen so that the reaction products thereof are essentially noncatalytic for an oxidation-reduction reaction with said oxidizing agent and said reducing agent, and said oxidizing agent and said reducing agent are essentially inert to oxidation-reduction reaction in the absence of said catalytic material.

Claim 3

A process according to claim 1 wherein said oxidizing agent is a cobalt(III) ion complex.

Claim 4

A process according to claim 2 wherein said reducing agent is capable of reducing silver halide to metallic silver.

Claim 5

A process according to claim 1 wherein said oxidizing agent is a cobalt(III) complex, said reducing agent is capable of reducing exposed silver halide to metallic silver, and said catalytic material is a zero valent metal or chalcogen of a Group VIII or 1B element.

Claim 6

A process according to claim 4 wherein said catalytic material is metallic silver.

Claim 7

A process according to claim 1 wherein said oxidizing agent is a cobalt(III) ion complex containing at least three ammine ligands.

Claim 8

A process according to claim 6 wherein said inert transition metal complex is a cobalt(III) complex having a net charge of +3.

Claim 9

A process according to claim 1 wherein said crosslinkable colloid is capable of being crosslinked by the reaction products of said redox reaction to provide at least 100 percent lower water solubility of said colloid at 90° F.

Claim 10

A process according to claim 1 wherein said crosslinkable colloid is a hardenable hydrophilic colloid which has a melting point of less than 150° F. and is capable of being hardened to provide a melting point differential between hardened and unhardened hydrophilic colloid of at least 20° F.

Claim 11

A process according to claim 1 wherein said crosslinkable colloid is a gelatin.

Claim 12

In an image-forming process wherein a photographic element containing at least one layer of an imagewise-exposed silver halide emulsion is processed in a processing solution which is substantially free of silver halide solvents to provide an imagewise distribution of tanned crosslinkable colloid in a layer of crosslinkable colloid, the improvement comprising employing in said process in reactive association (a) an inert transition metal complex oxidizing agent having a coordination number of 6 and which is capable of existing in at least two valence states and (b) a reducing agent which is capable of reducing exposed silver halide to metallic silver, wherein said oxidizing agent and said reducing agent undergo redox reaction in the presence of metallic silver and are essentially inert to oxidation-reduction reaction in the absence of said metallic silver, said oxidizing agent and said reducing agent being chosen so that the reaction products thereof are essentially noncatalytic for an oxidation-reduction reaction with said oxidizing agent and said reducing agent.

Claim 13

In an image-forming process wherein a photographic element containing at least one layer of an imagewise-exposed silver halide emulsion is processed in a processing solution which is substantially free of silver halide solvents to provide an imagewise distribution of tanned crosslinkable colloid in a layer of crosslinkable colloid, the improvement comprising employing in said process in reactive association (a) an inert transition metal complex oxidizing agent having a coordination number of 6 and which is capable of existing in at least two valence states and (b) a reducing agent which is capable of reducing exposed silver halide to metallic silver, wherein said oxidizing agent and said reducing agent undergo redox reaction in the presence of metallic silver and are essentially inert to oxidation-reduction reaction in the absence of said metallic silver, said oxidizing agent and said reducing agent being chosen so that the reaction products thereof are essentially noncatalytic for an oxidation-reduction reaction with said oxidizing agent and said reducing agent.

Claim 14

A process according to claim 11 wherein said inert transition metal complex is a cobalt(III) complex which has a net positive charge of +3. and contains at least three ammine ligands.

Claim 15

A process according to claim 11 wherein said reducing agent is a primary aromatic amino compound and a color coupler is present during said process, whereby a dye can be formed by reaction of the oxidized primary aromatic amine with said color coupler.

Claim 16

A process according to claim 11 wherein said inert transition metal complex is a cobalt complex having a coordination number of 6 and comprises a ligand selected from the group consisting of ethylenediamine, propylenediamine, diethylenetriamine, triethylenetetramine, amine, nitrate, nitrite, azide, chloride, thiocyanate, isothiocyanate, water and carbonate, said complex comprising (a) at least 2 ethylenediamine ligands or (b) at least 5 amine ligands or (c) at least 1 triethylenetetramine ligand or (d) at least 2 propylenediamine ligands.

Claim 17

A process according to claim 11 wherein said oxidizing agent is a cobalt(III) ion complex present in the processing composition in a concentration of at least 10 g./l. based on cobalt.

Claim 18

A process according to claim 11 wherein said crosslinkable colloid is a hardenable hydrophilic colloid.

Claim 19

A process according to claim 11 wherein said crosslinkable colloid is present at a coverage of from about 10 to about 2000 mg./ft. 2 .

Claim 20

A process according to claim 11 wherein the unhardened crosslinkable colloid is removed by washing after said tanning process.

Claim 21

A process according to claim 11 wherein said reducing agent is a tanning silver halide developer.

Claim 22

A process according to claim 11 wherein said photographic element contains less than 50 mg. of silver halide per ft. 2 based on silver.

Claim 23

A process according to claim 11 wherein said reducing agent is a primary aromatic amino silver halide developing agent.

Claim 24

A process according to claim 11 wherein a color coupler is present in said process and said reducing agent is a color silver halide developing agent.

Claim 25

A process according to claim 11 wherein said crosslinkable colloid is a hardenable gelatin which is present at a coverage of from about 10 to about 2000 mg./ft. 2 and said oxidizing agent is cobalt(III) hexammine chloride.

Claim 26

In a photographic process wherein an imagewise-exposed photographic element comprising a support having coated thereon silver halide grains dispersed in a crosslinkable colloid is developed to produce a metallic silver image and said colloid is crosslinked imagewise in the areas where metallic silver develops, the improvement which comprises conducting said photographic development with the combination of (a) a photographic developer and (b) an inert transition metal ion complex having a coordination number of 6 and which is capable of existing in at least two valence states, which is reduced by said photographic developer in the presence of metallic silver, the reduced form of said transition metal ion complex being a crosslinking agent for said colloid, wherein said photographic developer and said inert transition metal ion complex are essentially inert to oxidation-reduction reaction in the absence of said metallic silver.

Claim 27

In a photographic process wherein an imagewise-exposed photographic element comprising a support having coated thereon silver halide grains dispersed in a crosslinkable colloid is developed to produce a metallic silver image and said colloid is crosslinked imagewise in the areas where metallic silver develops, the improvement which comprises conducting said photographic development with the combination of (a) a photographic developer and (b) an inert transition metal ion complex having a coordination number of 6 and which is capable of existing in at least two valence states, which is reduced by said photographic developer in the presence of metallic silver, the reduced form of said transition metal ion complex being a crosslinking agent for said colloid, wherein said photographic developer and said inert transition metal ion complex are essentially inert to oxidation-reduction reaction in the absence of said metallic silver.

Claim 28

A photographic process as described in claim 24 wherein said crosslinkable colloid is unhardened gelatin, the photographic developer is a photographic tanning developing agent, and the oxidant is a cobalt complex having a coordination number of 6.

Claim 29

A photographic process as defined in claim 25 wherein said tanning developing agent is 4-phenylpyrocatechol and said cobalt complex is cobalt hexammine(III) chloride.

Claim 30

A photographic process as defined in claim 26 wherein said photographic element is treated with said combination of oxidant and reductant subsequent to the development of metallic silver.

Claim 31

A photographic process as defined in claim 27 wherein said hydrophilic colloid comprises at least partially unhardened gelatin, said reductant is 4-phenylpyrocatechol, and said oxidant is cobalt hexammine(III) chloride.