Roomlight-stable ultraviolet-response photothermographic imaging material

Claim 1

A thermophotographic layered construction comprising: a. a transparent or opaque substrate b. coated upon one surface of said substrate, a continuous layer of a dry silver dispersion coating, said coating comprisng: (1) a blend of organic silver full soap and half soap to provide in said layer a weight ratio of total silver in the coating to silver soap in the range of 1:7 to 1:4.2, (2) a polyvinyl acetal resin, said resin to silver soap weight ratio being in the range of 0.6:1 to 2:1, and c. a protective/reaction topcoat layer comprising a cellulose acetate resin admixed with an effective amount of a development accelerator, and construction further comprising d. 0.5 to 20 mole percent of halide ion compared to silver in said silver coating layer or said topcoat layer, at least 96 mole percent of said halide ion being chloride ion, and e. an effective amount of at least one antihalation agent incorporated in any of layers, a., b., c., or d., or in a separate layer between said substrate and said silver coating layer, said construction being intrinsically ultraviolet light-responsive and roomlight stable for at least one minute, and capable of forming graphic arts images having a contrast of at least 2.5.

Claim 9

A method for preparing a roomlight handleable photothermographic dry silver sheet material which comprises a dry silver dispersion coated on a substrate, halide ion being present in said silver dispersion or in a separate topcoat layer, said sheet material being capable of forming graphic arts images having a contrast of at least 2.5, said method comprisng the steps of: a. admixing, to prepare said dry silver dispersion coating layer, (1) at least 5 weight percent of the total weight of a polyvinyl acetal resin, and (2) a blend of organic silver full soap and half soap to provide in said layer a total silver to silver soap weight ratio in the range of 1:7 to 1:4.2, said total resin to silver soap weight ratio being in the range of 0.6:1 to 2:1, b. adding subsequently and further admixing, when said halide ion is to be present in said silver dispersion, 0.5 to 20 mole percent of halide ion compared to silver in said silver dispersion coating layer, at least 96 mole percent of said halide ion being chloride ion, or providing said halide ion in said separate topcoat layer, c. coating said dispersion on said substrate, and d. incorporating an effective amount of at least one antihalation agent in at least one of said silver dispersion layer, said substrate, said topcoat layer, or in a separate layer between said substrate and said silver dispersion layer.

Claim 10

A method for preparing a roomlight handleable photothermographic dry silver sheet material which comprises a dry silver dispersion coated on a substrate, halide ion being present in said silver dispersion or in a separate topcoat layer, said sheet material being capable of forming graphic arts images having a contrast of at least 2.5, said method comprisng the steps of: a. admixing, to prepare said dry silver dispersion coating layer, (1) at least 5 weight percent of the total weight of a polyvinyl acetal resin, and (2) a blend of organic silver full soap and half soap to provide in said layer a total silver to silver soap weight ratio in the range of 1:7 to 1:4.2, said total resin to silver soap weight ratio being in the range of 0.6:1 to 2:1, b. adding subsequently and further admixing, when said halide ion is to be present in said silver dispersion, 0.5 to 20 mole percent of halide ion compared to silver in said silver dispersion coating layer, at least 96 mole percent of said halide ion being chloride ion, or providing said halide ion in said separate topcoat layer, c. coating said dispersion on said substrate, and d. incorporating an effective amount of at least one antihalation agent in at least one of said silver dispersion layer, said substrate, said topcoat layer, or in a separate layer between said substrate and said silver dispersion layer.