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US3985561A Expired / Lapsed US ⏱️ 0.0 years remaining

Diffusion transfer process using silver halide emulsions with 90% chloride and high binder to silver halide ratios

Assignee: Agfa Gevaert NV
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Filing: 1974-06-20
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Granted: 1976-10-12
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Expires: 1994-06-20
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Abstract

Abstract A process for producing continuous tone images on an image-receiving material in a diffusion transfer process.

Inventors

  • 👤 Louis Maria De Haes
  • 👤 Leon Louis Vermeulen
  • 👤 Hugo Karel Gevers
  • 👤 Stephan Jeanne Bongaerts
  • 👤 Paul Desire Van Pee
  • 👤 Werner Krafft

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 02:52
CPC Classifications
G; G03; G03C; G03C8/00; G03C8/02; G03C8/04; G03C8/06

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 176 words
A process for producing continuous tone images on an image-receiving material in a diffusion transfer process comprising the steps of: a. exposing to a continuous tone original a light-sensitive silver halide emulsion layer containing a mixture of silver chloride and silver iodide and/or silver bromide dispersed in a hydrophilic colloid binder wherein the silver chloride is present in an amount of at least 90 mole % based on the total amount of silver halide and the weight ratio of hydrophilic colloid binder to silver halide expressed as silver nitrate is comprised between about 3:1 and about 10:1, b. wetting the light-sensitive layer while in close contact with an image-receiving layer separate from said emulsion layer by means of an aqueous alkaline composition in the presence of at least one developing agents for the exposed silver halide, at least one silver complexing agents to dissolve the unexposed and undeveloped silver halide, and at least one agents promoting the reduction to metallic silver of said dissolved silver salt complexes to deposit a silver image on the image-receiving material.
Claim 2
Dependent Claim 176 words
A process for producing continuous tone images on an image-receiving material in a diffusion transfer process comprising the steps of: a. exposing to a continuous tone original a light-sensitive silver halide emulsion layer containing a mixture of silver chloride and silver iodide and/or silver bromide dispersed in a hydrophilic colloid binder wherein the silver chloride is present in an amount of at least 90 mole % based on the total amount of silver halide and the weight ratio of hydrophilic colloid binder to silver halide expressed as silver nitrate is comprised between about 3:1 and about 10:1, b. wetting the light-sensitive layer while in close contact with an image-receiving layer separate from said emulsion layer by means of an aqueous alkaline composition in the presence of at least one developing agents for the exposed silver halide, at least one silver complexing agents to dissolve the unexposed and undeveloped silver halide, and at least one agents promoting the reduction to metallic silver of said dissolved silver salt complexes to deposit a silver image on the image-receiving material.
Claim 3
Dependent Claim 16 words
Process according to claim 1, wherein the hydrophilic colloid binder of the silver halide is gelatin.
Claim 4
Dependent Claim 17 words
Process according to claim 1, wherein the gelatin/silver halide ratio is between 3.5:1 and 6.7:1 by weight.
Claim 5
Dependent Claim 33 words
Process according to claim 1, wherein the silver iodide and/or bromide is present in an amount comprised between about 0.5 and about 5 mole % based on the total mole of silver halide.
Claim 6
Dependent Claim 32 words
Process according to claim 1, wherein the silver iodide and/or bromide are formed during emulsion preparation by means of the reaction of a cadmium or potassium iodide and/or bromide with silver nitrate.
Claim 7
Dependent Claim 40 words
Process according to claim 1, wherein the light-sensitive element comprises as developing agents hydroquinone in an amount of between about 0.3 g and about 3 g/sq.m and 1-phenyl-4-methyl-3-pyrazolidone in an amount of between about 0.075 g and about 0.75 g/sq.m.
Claim 8
Dependent Claim 21 words
Process according to claim 1, wherein the alkaline composition contains from about 17.5 g/l to about 50 g/l of sodium thiosulphate.

References Cited (Backward Citations)

US3666460A Cited
US3615520A Cited
US3784381A Cited
US3806342A Cited
US3847617A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1979-10-12 1980-04-12 1980-10-12 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1983-10-12 1984-04-12 1984-10-12 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1987-10-12 1988-04-12 1988-10-12 $7700.00 Window Closed / Lapsed

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