Protective overcoats for thermally developable materials

A thermally developable organic-solvent based material that comprises a support having on at least one side thereon, one or more organic-solvent coated buried thermally developable imaging layers comprising a polyvinyl acetal 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 over the one or more organic-solvent coated buried thermally developable imaging layers, an outermost organic-solvent coated overcoat layer comprising a cellulose acetate polymer, and
• having an interlayer comprising an organic-solvent coated alkyl vinyl ether/maleic anhydride copolymer or an alkylethylene/maleic anhydride copolymer or mixtures thereof that is located between said thermally developable layer(s) and said outermost overcoat layer.

A black-and-white, organic solvent-based photothermographic material that comprises a support having on an imaging side thereon, one or more organic-solvent coated buried photothermographic emulsion layers, comprising 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 polyvinyl butyral binder, and
• an outermost organic-solvent coated overcoat layer disposed over said photothermographic emulsion layers, said outermost organic-solvent coated overcoat layer comprising a mixture of cellulose acetate polymer and methyl vinyl ether/maleic anhydride copolymer.