Thermally developable materials with buried conductive backside coatings
AssigneeCarestream Health, Inc.
InventorsThomas J. Ludemann, Gary E. LaBelle, Thomas J. Kub, Kumars Sakizadeh, Sharon M. Simpson
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Abstract
Thermally developable materials including photothermographic and thermographic materials have a buried conductive backside layer comprising one or more binder polymers in which are dispersed each of at least two types of conductive materials: (1) nanoparticles of one or more conductive metal compounds, and (2) one or more organic solvent soluble inorganic alkali metal salt antistatic compounds. These buried conductive backside coatings provide conductivity that is affected minimally by humidity.
Claims23
A thermally developable material that comprises a support having on the frontside thereof, one or more thermally developable imaging layers comprising a binder and in reactive association, a non-photosensitive source of reducible silver ions, and a reducing agent composition for said non-photo-sensitive source reducible silver ions, and
- having disposed on the backside of said support,
- an organic solvent-based buried conductive backside layer comprising one or more binder polymers having dispersed therein, nanoparticles of a conductive metal compound and an antistatic compound that is an organic solvent soluble inorganic alkali metal salt that together are present in an amount sufficient to provide a water electrode resistivity of 1012 ohm/sq at 21.1° C. and 50% relative humidity, and a static decay time of less than 100 seconds at 21.1° C. and 20% relative humidity,
- and an organic solvent-based outermost backside layer.
A black-and-white, organic solvent-based photothermo-graphic material comprising a support and
- A) having on an imaging side of said support, one or more photothermographic emulsion layers, and a protective layer disposed over said photothermographic emulsion layers, and in reactive association:
- photosensitive grains of silver bromide or iodobromide that are sensitized to an exposure wavelength of at least 600 nm,
- one or more silver salts of aliphatic fatty acids including silver behenate,
- a reducing agent composition comprising a hindered phenol, a hindered bisphenol, or a combination thereof, and
- a hydrophobic, organic solvent-soluble binder,
- B) having on the backside of said support,
- a hydrophobic organic solvent-based buried conductive backside layer comprising one or more first organic solvent soluble hydrophobic binder polymers in which are dispersed nanoparticles of one or more conductive metal oxides and one or more antistatic compounds that includes an organic solvent soluble inorganic alkali metal salt, that together are present in an amount of from about 0.05 to about 2 g/m2 to provide a water electrode resistivity of 11 log ohm/sq at 21.1° C. and 50% relative humidity, and
- disposed directly on said buried conductive backside layer, an organic solvent-based outermost backside layer comprising one or more second hydrophobic binder polymers at least one of which differs from said first hydrophobic binder polymers, and one or more of a polysiloxane, amorphous silica particles, a smectite clay that has been modified with a quaternary ammonium compound, wax or polytetrafluoroethylene particulates,
- wherein:
- C) the silver coating weight of said photothermographic material is from about 1 to about 2 g/m2,
- the absorbance on said imaging side at an exposure wavelength is at least 0.6,
- the absorbance on said backside at an exposure wavelength is at least 0.2,
- said buried conductive backside layer and said outermost backside layer exhibit a haze of 13% or less, and
- said buried conductive backside layer exhibits a static decay time of 25 seconds or less.
A method of preparing a thermally developable material that comprises a support having on one side thereof, one or more thermally developable imaging layers comprising a binder and in reactive association, a non-photosensitive source of reducible silver ions, and a reducing agent composition for said non-photosensitive source reducible silver ions, and
- having disposed on the backside of said support, a buried conductive backside layer comprising one or more binder polymers, in which are dispersed nanoparticles of a conductive metal compound and one or more antistatic compounds that include an organic solvent soluble inorganic alkali metal salt, that together are present in an amount sufficient to provide a water electrode resistivity of 1012 ohm/sq at 21.1° C. and 50% relative humidity, and a static decay time of less than 100 seconds at 21.1° C. and 20% relative humidity, and an outermost backside layer,
- wherein said buried conductive backside layer and said outermost backside layer are provided by applying buried conductive backside layer and outermost backside layer formulations in the same or different hydrophobic organic solvents that exclude methanol or include methanol in an amount of 10% or less, based on total organic solvent volume.
Dependencies are inferred from the claim text.