Silver image stabilization

Claim 2

A photographic silver diffusion transfer film unit which comprises photosensitive silver halide, silver precipitating nuclei and a stabilizing compound consisting of a noble metal complexed with a ligand, said ligand being adapted to hydrolyze in aqueous alkali to provide a diffusible complex of said noble metal.

Claim 3

The film unit of claim 1 wherein said stabilizing compound is XS(CH.sub.2).sub.n COOR wherein X is a noble metal below silver in the Electromotive Force Series of Elements n is 1, 2 or 3 and R is an alkyl or substituted alkyl group removable by alkaline hydrolysis.

Claim 4

The film unit of claim 2 wherein R is a 1 to 4 carbon alkyl group.

Claim 5

The film unit of claim 2 wherein X is gold, palladium or platinum.

Claim 6

The film unit of claim 4 wherein said support is transparent.

Claim 7

The film unit of claim 5 which includes an additive color screen intermediate said transparent support and said other layers.

Claim 8

The film unit of claim 2 wherein said compound is AuSCH 2 COOCH 3 .

Claim 9

The film unit of claim 2 wherein said compound is AuSCH 2 CH 2 COOCH 3 .

Claim 10

The film unit of claim 1 wherein said film unit comprises a support carrying on one surface a layer comprising silver precipitating nuclei and a layer comprising photosensitive silver halide crystals.

Claim 11

The film unit of claim 9 wherein said stabilizing compound is disposed in said layer containing said photosensitive silver halide crystals.

Claim 12

The film unit of claim 9 wherein said stabilizing compound is disposed in a layer adjacent said layer containing said photosensitive silver halide crystals.

Claim 13

The film unit of claim 9 which includes a common support and wherein said layer containing silver precipitating nuclei is positioned intermediate said support and said photosensitive silver halide layer.

Claim 14

The film unit of claim 9 wherein said photosensitive silver halide layer and said layer containing said silver precipitating nuclei are carried on separate supports.

Claim 15

The film unit of claim 13 wherein said film unit additionally includes a stripping layer intermediate said layer containing said silver precipitating nuclei and said photosensitive silver halide layer containing said silver halide.

Claim 16

The film unit as defined in claim 9 which includes a processing composition permeable layer substantially devoid of silver halide and silver precipitating agents disposed on the surface of the film unit most distant from said support, said permeable layer having said stabilizing compound disposed therein.

Claim 17

The film unit as defined in claim 9 which includes an additive color screen.

Claim 18

The film unit of claim 1 wherein said stabilizing compound is present at a level of about 5 to 100 mgs of noble metal per g of silver.

Claim 19

A silver diffusion transfer photographic process which comprises, in combination, the steps of: (a) exposing a photographic film unit comprising photosensitive silver halide and silver precipitating nuclei; (b) contacting said exposed film unit with an aqueous alkaline processing composition containing a silver halide developing agent an a silver halide solvent, thereby providing a visible diffusion transfer silver image to said unit, as a function of the point-to-point degree of exposure thereof; and (c) contacting said silver image with a soluble complex of a noble metal derived from a stabilizing compound consisting of a noble metal complexed with a ligand, said ligand being adapted to hydrolyze in aqueous alkali whereby said ligand is hydrolyzed in said aqueous alkaline processing composition thereby providing said soluble complex of a noble metal.

Claim 20

A silver diffusion transfer photographic process which comprises, in combination, the steps of: (a) exposing a photographic film unit comprising photosensitive silver halide and silver precipitating nuclei; (b) contacting said exposed film unit with an aqueous alkaline processing composition containing a silver halide developing agent an a silver halide solvent, thereby providing a visible diffusion transfer silver image to said unit, as a function of the point-to-point degree of exposure thereof; and (c) contacting said silver image with a soluble complex of a noble metal derived from a stabilizing compound consisting of a noble metal complexed with a ligand, said ligand being adapted to hydrolyze in aqueous alkali whereby said ligand is hydrolyzed in said aqueous alkaline processing composition thereby providing said soluble complex of a noble metal.

Claim 21

The process of claim 18 wherein said stabilizing compound is a compound of the formula XS(CH.sub.2).sub.n COOR wherein X is a noble metal below silver in the Electromotive Force Series of Elements, n is 1, 2 or 3 and R is an alkyl or substituted alkyl group adapted to be removable by alkaline hydrolysis.

Claim 22

The process of claim 19 wherein R is a 1-4 carbon alkyl group.

Claim 23

The process of claim 19 wherein said compound is AuSCH 2 COOCH 3 .

Claim 24

The process of claim 19 wherein said compound is AuSCH 2 CH 2 COOCH 3 .

Claim 25

The process of claim 18 wherein said compound is present at a level of 5 to 100 mgs of noble metal per g of silver.

Claim 26

The process of claim 18 wherein said film unit includes an additive color screen.

Claim 27

An additive color diffusion transfer film unit which comprises a transparent support carrying, in order, an additive color screen, a layer comprising palladium metal silver-precipitating nuclei, a photosensitive silver halide emulsion layer; and an antihalation layer; wherein said antihalation layer includes a stabilizing compound consisting of a noble metal complexed with a ligand, said ligand being adapted to hydrolyze in aqueous alkali to provide a diffusible complex of said noble metal.

Claim 28

An additive color diffusion transfer film unit which comprises a transparent support carrying, in order, an additive color screen, a layer comprising palladium metal silver-precipitating nuclei, a photosensitive silver halide emulsion layer; and an antihalation layer; wherein said antihalation layer includes a stabilizing compound consisting of a noble metal complexed with a ligand, said ligand being adapted to hydrolyze in aqueous alkali to provide a diffusible complex of said noble metal.

Claim 29

The film unit of claim 25 wherein said stabilizing compound is a compound of the formula XS(CH.sub.2).sub.n COOR wherein X is a noble metal below silver in the Electromotive Force Series of Elements, n is 1, 2 or 3 and R is an alkyl or substituted alkyl group removable by alkaline hydrolysis.