Thermally developable emulsions and imaging materials containing mixture of silver ion reducing agents
AssigneeEastman Kodak Company
InventorsJohn W. Boettcher, Paul L. Zengerle, Roger L. Klaus
Life of this patent
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Abstract
Aqueous-based thermally sensitive emulsions and imaging materials include two or more hindered phenol silver ion reducing agents in a non-crystalline reducing agent composition. Such compositions can be provided as evaporated dispersions and can be formulated in aqueous coating compositions to provide thermally developable materials such as thermographic and photothermographic materials.
Claims31
A thermally sensitive emulsion comprising:
- a) a non-photosensitive source of reducible silver ions,
- b) a hydrophilic binder, and
- c) a non-crystalline reducing agent composition for said reducible silver ions, which non-crystalline reducing agent composition includes two or more hindered phenol silver ion reducing agents.
A thermally developable material comprising a support having thereon at least one imaging layer comprising a hydrophilic binder, and having in reactive association:
- a) a non-photosensitive source of reducible silver ions, and
- b) a non-crystalline reducing agent composition for said reducible silver ions, which non-crystalline reducing agent composition includes two or more hindered phenol silver ion reducing agents.
A photothermographic material comprising a support having thereon at least one imaging layer comprising a hydrophilic binder, and having in reactive association:
- a) a photosensitive silver halide,
- b) a non-photosensitive source of reducible silver ions, and
- c) a non-crystalline reducing agent composition for said reducible silver ions, which non-crystalline reducing agent composition includes two or more hindered phenol silver ion reducing agents.
A photothermographic material comprising a transparent support having thereon an aqueous-based imaging layer comprising gelatin or a gelatin derivative as binder, and having in reactive association:
- a) photosensitive silver bromide, silver iodobromide, or both,
- b) a non-photosensitive source of reducible silver ions that comprises one or more silver carboxylates provided as an aqueous nanoparticulate dispersion, at least one of which silver carboxylates is silver behenate,
- c) a non-crystalline reducing agent composition for said reducible silver ions that includes a mixture of 2,2′(2-methylpropylidene)bis(4,6-dimethyl-phenol) (DEV-1) and 2,2′-(3,5,5-trimethylhexylidene)bis(4,6-dimethyl-phenol) (DEV-2), which mixture is provided as an evaporated dispersion, and
- d) one or more antifoggants, toners, or spectral sensitizing dyes,
- said photothermographic material further comprising an aqueous-based surface protective overcoat over said imaging layer, and an aqueous-based antihalation layer on the backside of said support.
A method of making a photothermographic emulsion comprising the steps of:
- A) dissolving two or more crystalline hindered phenol silver ion reducing agents in one or more low boiling organic solvents to form a solvent solution, with or without one or more permanent high boiling organic solvents,
- B) combining said solvent solution with a hydrophilic binder and a surfactant to form a two-phase mixture,
- C) emulsifying said two-phase mixture,
- D) removing said one or more low boiling organic solvents to provide a non-crystalline reducing agent composition, and
- E) combining said non-crystalline reducing agent composition with a photosensitive silver halide and a non-photosensitive source of reducible silver ions.
Dependencies are inferred from the claim text.