Method for preparing electrically-conductive silver images
View Patent ↗Electrically-conductive articles are prepared to have electrically-conductive silver metal electrode grids on one or both supporting sides of a transparent substrate. Such articles are prepared by imagewise exposing conductive film element precursors having photosensitive silver halide layers, followed by development, fixing, and conductivity enhancement. The resulting silver image(s) can be treated with a stabilizing solution containing 0.5-50 mmol/l of specific stabilizing agents.
1. A method for providing a first electrically-conductive silver image, the method comprising, in order:
imagewise exposing a conductive film element precursor that comprises a transparent substrate comprising a first supporting side and an opposing second supporting side and a photosensitive silver halide emulsion layer on the first supporting side of the substrate, to radiation to provide a first latent silver image in the photosensitive silver halide emulsion layer on the first supporting side of the substrate,
developing the first latent silver image on at least the first supporting side of the substrate to provide a first silver image corresponding to the first latent silver image on the first supporting side of the substrate, using a black-and-white developing solution,
fixing to remove silver halide remaining in the photosensitive silver halide emulsion layer on the first supporting side of the substrate,
treating the first silver image on the first supporting side of the substrate to enhance silver conductivity of the first silver image, and
treating the first silver image with a stabilizing solution comprising at least 0.5 mmol/l and up to and including 50 mmol/l of a heterocyclic thiol, a benzotriazole, a tetraazoindene, or a purine derivative as a stabilizing agent,
to provide an electrically-conductive silver image on the first supporting side of the substrate.
2. The method of claim 1 , wherein the stabilizing solution comprises at least 1 mmol/l and up to and including 10 mmol/l of a heterocyclic thiol as a stabilizing agent.
3. The method of claim 1 , wherein treating the first silver image to enhance conductivity of the first silver image is carried out using a conductivity enhancing solution comprising at least 0.5 weight % of an amine borane conductivity enhancing agent.
4. The method of claim 1 , further comprising, after treating the first silver image to enhance its conductivity and before treating with the stabilizing solution, washing and drying the first silver image.
5. The method of claim 4 , wherein the sequence of treating the first silver image to enhance its conductivity, washing and drying the first silver image, is carried out two or more times before treating the first silver image with the stabilizing solution.
6. The method of claim 1 , wherein after developing the first latent silver image with the black-and-white developing solution and before fixing, further treating the first latent silver image with a solution physical developing solution.
7. The method of claim 1 , wherein the substrate exhibits at least 80% integrated transmittance.
8. The method of claim 1 for providing a second electrically-conductive silver image on the opposing second supporting side of the substrate that exhibits at least 80% integrated transmittance, wherein the conductive film element precursor further comprises a photosensitive silver halide emulsion layer disposed on the opposing second supporting side of the substrate, and
the method further comprises:
imagewise exposing the photosensitive silver halide emulsion layer on the opposing second supporting side of the substrate to radiation to provide a second latent silver image in the photosensitive silver halide emulsion layer on the opposing second supporting side of the substrate,
developing the second latent silver image on the opposing second supporting side to provide a second silver image corresponding to the second latent silver image on the opposing second supporting side of the substrate, using a black-and-white developing solution,
fixing to remove silver halide remaining in the second photosensitive silver halide emulsion layer on the opposing second supporting side of the substrate,
treating the second silver image on the opposing second supporting side of the substrate to enhance silver conductivity of the second silver image, and
treating the first silver image with a stabilizing solution comprising at least 0.5 mmol/l and up to and including 50 mmol/l weight % of a heterocyclic thiol, a benzotriazole, a tetraazoindene, or a purine derivative as a stabilizing agent,
to provide a second electrically-conductive silver image on the opposing second supporting side of the substrate.
9. The method of claim 8 , wherein forming the first electrically-conductive silver image and the second electrically-conductive silver image by imagewise exposing and processing of the respective photosensitive silver halide emulsion layers are carried out simultaneously using the same processing solutions.
10. The method of claim 9 , wherein the sequence of treating the first silver image and the second silver image to enhance their conductivity, washing, and drying the first silver image and the second silver image, is carried out two or more times before treating the first silver image and the second silver image with the stabilizing solution.
11. The method of claim 8 , wherein after developing the second latent silver image with the black-and-white developing solution and before fixing, further treating the second latent silver image with a solution physical developing solution.
12. The method of claim 1 , wherein the conductive film element precursor comprises a transparent polyester substrate and has on the first supporting side thereof, in order, the photosensitive silver halide emulsion layer comprising silver ions and at least one hydrophilic binder in a weight ratio of at least 2:1 and up to and including 5:1, and a hydrophilic overcoat as the outermost layer, which hydrophilic overcoat comprising one or more hydrophilic binders and optionally at least 5 mg Ag/m 2 and up to and including 75 mg Ag/m 2 from silver halide.
13. The method of claim 12 , wherein the hydrophilic overcoat further comprises one or more UV radiation absorbers in an amount of at least 5 mg/m 2 and up to and including 100 mg/m 2 .
14. The method of claim 12 , wherein the hydrophilic overcoat comprises at least 5 mg Ag/m 2 and the silver halide grain ECD to dry thickness ratio is from 0.5:1 to and including 1.25:1.
15. The method of claim 1 , wherein the photosensitive silver halide emulsion layer has a swell ratio of at least 150% and up to and including 300%.
16. The method of claim 8 , wherein the conductive film element precursor comprises a transparent polyester substrate and has on the first supporting side thereof, in order, the photosensitive silver halide emulsion layer comprising silver ions and at least one hydrophilic binder in a weight ratio of at least 2:1 and up to and including 5:1, and a hydrophilic overcoat as the outermost layer, which hydrophilic overcoat comprising one or more hydrophilic binders and optionally at least 5 mg Ag/m 2 and up to and including 75 mg Ag/m 2 from silver halide, and
the conductive film element precursor has on the opposing second supporting side of the transparent polyester substrate, in order, a photosensitive silver halide emulsion layer comprising silver ions and at least one hydrophilic binder in a weight ratio of at least 2:1 and up to and including 5:1, and a hydrophilic overcoat as the outermost layer, which hydrophilic overcoat comprising one or more hydrophilic binders and optionally at least 5 mg Ag/m 2 and up to and including 75 mg Ag/m 2 from silver halide.