Thermally developable materials with improved conductive layer

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 non-imaging backside conductive layer comprising a conductive metal oxide in a one or more binder polymers, and a first layer disposed over said non-imaging backside conductive layer, wherein:
• 1) said backside conductive layer has a water electrode resistivity measured at 21.1° C. and 50% relative humidity of 1×1012 ohms/sq or less,
• 2) the one or more binder polymers in said backside conductive layer is at least 35 weight %,
• 3) said backside conductive layer has a normalized average gap density of at least 0.03 (gaps/μm3)/(mg/ft2), said gaps being at least 0.25 μm between conductive particles or clusters, and
• 4) said backside conductive layer has a normalized average metal oxide cluster size distribution of at least 0.012 (μm)/(mg/ft2).

A photothermographic 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 photosensitive silver halide, 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 simultaneously coated first layer and a non-imaging backside conductive layer:
• a) said first layer comprising a film-forming polymer, and
• b) interposed between said support and said first layer and directly adhering said first layer to said support, said non-imaging backside conductive layer comprising non-acicular metal antimonate in a mixture of two or more polymers that include a first polymer serving to promote adhesion of said backside conductive layer directly to said support, and a second polymer that is different than and forms a single phase mixture with said first polymer, wherein:
• 1) said backside conductive layer has a water electrode resistivity measured at 21.1° C. and 50% relative humidity of 1×1012 ohms/sq or less,
• 2) the total amount of mixture of two or more polymers in said backside conductive layer is at least 35 weight %,
• 3) said non-acicular metal antimonate is present in an amount of less than 2 g/m2,
• 4) said film-forming polymer of said first layer and said second polymer of said backside conductive layer are the same or different polyvinyl acetal resins, polyester resins, cellulosic polymers, maleic anhydride-ester copolymers, or vinyl polymers,
• 5) said backside conductive layer has a normalized average gap density of at least 0.03 (gaps/μm3)/(mg/ft2), said gaps being at least 0.25 μm between conductive particles or clusters, and
• 6) said backside conductive layer has a normalized average metal oxide cluster size distribution of at least 0.012 (μm)/(mg/ft2).

A black-and-white photothermographic material that comprises a transparent polymeric support having on one side thereof one or more thermally developable imaging layers comprising predominantly one or more hydrophobic binders, and in reactive association, preformed photosensitive silver bromide or silver iodobromide present as tabular and/or cubic grains, a non-photosensitive source of reducible silver ions that includes silver behenate, a reducing agent composition for said non-photosensitive source reducible silver ions comprising a hindered phenol, and a protective layer disposed over said one or more thermally developable imaging layers, and

• having disposed on the backside of said support, a simultaneously coated backside protective layer and a non-imaging backside conductive layer:
• a) said backside protective layer comprising a film-forming polymer that is cellulose acetate butyrate and an antihalation composition, and
• b) interposed between said support and said backside protective layer and directly adhering said backside protective layer to said support, said non-imaging backside conductive layer comprising non-acicular metal antimonate clusters in a mixture of two or more polymers that include a first polymer serving to promote adhesion of said conductive layer directly to said support, and a second polymer that is different than and forms a single phase mixture with said first polymer,
• wherein said first polymer of said backside conductive layer is a polyester and said second polymer of said backside conductive layer is cellulose acetate butyrate,
• wherein said non-acicular metal antimonate clusters are composed of zinc antimonate (ZnSb2O6) that is present at a coverage of from about 0.2 to about 0.6 g/m2, the dry thickness of said backside conductive layer is from about 0.20 to about 0.8 μm, the weight % of said polymer mixture in said backside conductive layer is from about 45 to about 55 weight %, and said backside conductive layer has a water electrode resistivity measured at 21.1° C. and 50% relative humidity of less than about 1×1011 ohms/sq,
• a normalized average gap density of at least 0.03 (gaps/μm3)/(mg/ft2), said gaps being at least 0.25 μm between conductive particles or clusters, and
• said backside conductive layer having a normalized average metal oxide cluster size distribution of at least 0.012 (μm)/(mg/ft2).

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, comprising:

• simultaneously coating on the backside of said support both a non-imaging backside conductive formulation comprising a conductive metal oxide in one or more binder polymers, and a first layer formulation, out of the same or different organic solvents, to provide first layer over a non-imaging backside conductive layer,
• 1) said backside conductive layer, when dried having a water electrode resistivity measured at 21.1° C. and 50% relative humidity of 1×1012 ohms/sq or less,
• 2) the total dry amount of said one or more binder polymers in said backside conductive layer is at least 35 weight %,
• 3) said conductive metal oxide is present in an amount of less than 2 g/m2.
• 4) said backside conductive layer having a normalized average gap density of at least 0.03 (gaps/μm3)/(mg/ft2), said gaps being at least 0.25 μm between conductive particles or clusters, and
• 5) said backside conductive layer having a normalized average metal oxide cluster size distribution of at least 0.012 (μm)/(mg/ft2).