Silver salt-toner co-precipitates and imaging materials

A method of making a co-precipitate particle of first and second organic silver salts, said first organic silver salt comprising a silver salt of a nitrogen-containing heterocyclic compound containing an imino group, and said second organic silver salt uniformly distributed throughout the volume of said particle and comprising a silver salt of a mercaptotriazole, said method comprising:

• A) preparing aqueous solution A containing a nitrogen-containing heterocyclic compound containing an imino group,
• A′) preparing aqueous solution A′ containing a mercaptotriazole, wherein solutions A and A′ are the same solution,
• B) preparing aqueous solution B of silver nitrate, and
• C) simultaneously adding said aqueous solutions A and B to a reaction vessel containing an aqueous dispersion of a hydrophilic polymer binder or a water-dispersible polymer latex binder that has a pH of from about 7.5 to about 10, via controlled double-jet precipitation, while maintaining a constant temperature of from about 30 to about 75° C., a constant pH, and a constant vAg equal to or greater than −50 mV in said reaction vessel,
• thereby preparing in said reaction vessel a dispersion of said hydrophilic polymer binder or said water-dispersible polymer latex binder and co-precipitate particles of said first and second silver salts, and said hydrophilic polymer binder or said water-dispersible polymer latex binder being present in said dispersion in an amount of from about 2 to about 10 weight %,
• wherein said second organic silver salt comprises a silver salt of a mercaptotriazole having the following Structure (I):
• wherein R1 and R2 independently represent hydrogen, an alkyl group, an alkenyl group, a cycloalkyl group, an aromatic or non-aromatic heterocyclyl group, an amino or amide group, an aryl group, or a Y1—(CH2)k— group wherein Y1 is an aryl group or an aromatic or non-aromatic heterocyclyl group, and k is 1–3,
• or R1 and R2 taken together can form a 5- to 7-membered aromatic or non-aromatic nitrogen-containing heterocyclic ring,
• or still again, R1 or R2 can represent a divalent linking group linking two mercaptotriazole groups, and
• R2 may further represent carboxy or its salts,
• provided that R1 and R2 are not simultaneously hydrogen, and when R1 is an unsubstituted phenyl group, R2 is not hydrogen.

A method of making a co-precipitate comprising:

• A) preparing aqueous solution A containing a benzotriazole at a concentration of from about 2 to about 4 mol/l,
• A′) preparing aqueous solution A′ that is different from solution A and contains a mercaptotriazole of Structure (T-1) at a concentration of from about 0.5 to about 3 mol/l,
• B) preparing aqueous solution B of silver nitrate, and
• C) simultaneously adding said aqueous solutions A and B to a reaction vessel containing an aqueous dispersion of a hydrophilic polymer binder or a water-dispersible polymer latex binder that has a pH of from about 7.5 to about 10, via controlled double-jet precipitation, while maintaining a constant temperature of from about 30 to about 75° C., a constant pH, and a constant vAg equal to or greater than −50 mV in said reaction vessel,
• E) adding solution A′ to said reaction vessel during step C but only after at least 75 volume % of solution B has been added to said reaction vessel,
• thereby preparing in said reaction vessel a dispersion of said hydrophilic polymer binder or said water-dispersible polymer latex binder and particles of the co-precipitate of said first and second organic silver salts, and said hydrophilic polymer binder or said water-dispersible polymer latex binder being present in said dispersion in an amount of from about 2 to about 10 weight %,

A black-and-white photothermographic material comprising a support and having thereon at least one thermally developable imaging layer comprising a hydrophilic polymer binder or a water-dispersible polymer latex binder and in reactive association:

• a. a photosensitive silver halide that is spectrally sensitized to a wavelength of from about 300 to about 450 nm,
• b. a non-photosensitive source of reducible silver ions, and
• c. a reducing agent for said reducible silver ions,
• wherein said non-photosensitive source of reducible silver ions predominantly comprises a co-precipitate particle comprising first and second organic silver salts, said first organic silver salt comprising a silver salt of a nitrogen-containing heterocyclic compound containing an imino group, and said second organic silver salt being uniformly distributed throughout the volume of said particle and comprising a silver salt of a mercaptotriazole.

A black-and-white photothermographic material comprising a support and having thereon at least one thermally developable imaging layer comprising a hydrophilic polymer binder or a water-dispersible polymer latex binder and in reactive association:

• a. a photosensitive silver halide,
• b. a non-photosensitive source of reducible silver ions, and
• c. a reducing agent for said reducible silver ions,
• wherein said non-photosensitive source of reducible silver ions predominantly comprises a co-precipitate particle comprising first and second organic silver salts, said first organic silver salt comprising a silver salt of a nitrogen-containing heterocyclic compound containing an imino group, and said second organic silver salt comprising a silver salt of a mercaptotriazole,
• wherein said first organic silver salt comprising a silver salt of a benzotriazole, and said second organic silver salt is present within a localized portion that is from about 75 to 100 volume % of said co-precipitate particle wherein 100 volume % represents its outer surface and comprises a silver salt of a mercaptotriazole that is the silver salt of Compound (T-1),

A black-and-white photothermographic material comprising a support and having thereon at least one thermally developable imaging layer comprising a hydrophilic polymer binder or a water-dispersible polymer latex binder and in reactive association:

• a. a photosensitive silver halide present as ultrathin tabular grains,
• b. a non-photosensitive source of reducible silver ions, and
• c. a reducing agent for said reducible silver ions,
• wherein said non-photosensitive source of reducible silver ions comprises a co-precipitate particle comprising first and second organic silver salts, said first organic silver salt comprising a silver salt of a nitrogen-containing heterocyclic compound containing an imino group, and said second organic silver salt being uniformly distributed throughout the volume of said particle and comprising a silver salt of a mercaptotriazole.

A black-and-white photothermographic material comprising a support having on a frontside thereof,

• a) one or more frontside thermally developable imaging layers comprising a hydrophilic polymer binder or a water-dispersible polymer latex binder, and in reactive association, a photosensitive silver halide, a non-photosensitive source of reducible silver ions, and a reducing agent for said non-photosensitive source of reducible silver ions,
• b) said material comprising on the backside of said support, one or more backside thermally developable imaging layers having the same or different composition as said frontside thermally developable imaging layers, and
• c) optionally, an outermost protective layer disposed over said one or more thermally developable imaging layers on either or both sides of said support,
• wherein said non-photosensitive source of reducible silver ions comprises a co-precipitate particle comprising first and second organic silver salts, said first organic silver salt comprising a silver salt of a nitrogen-containing heterocyclic compound containing an imino group, and said second organic silver salt comprising a silver salt of a mercaptotriazole being uniformly distributed throughout the volume of said particle.

A black-and-white photothermographic material comprising a support having on a frontside thereof,

• a) one or more frontside thermally developable imaging layers comprising a hydrophilic polymer binder or a water-dispersible polymer latex binder, and in reactive association, a photosensitive silver halide, a non-photosensitive source of reducible silver ions, and a reducing agent for said non-photosensitive source of reducible silver ions,
• b) said material comprising on the backside of said support, one or more backside thermally developable imaging layers having the same or different composition as said frontside thermally developable imaging layers, and
• c) optionally an outermost protective layer disposed over said one or more thermally developable imaging layers on either or both sides of said support,
• wherein said non-photosensitive source of reducible silver ions comprises a co-precipitate particle comprising first and second organic silver salts, said first organic silver salt comprising a silver salt of a nitrogen-containing heterocyclic compound containing an imino group, and said second organic silver salt being uniformly distributed throughout the volume of said particle and comprising a silver salt of a mercaptotriazole,
• wherein said thermally developable imaging layers on both sides of said support are essentially the same, said reducing agent is a fatty acid ester of ascorbic acid, said photosensitive silver halide is present as tabular grains of silver bromide or silver iodobromide, said first organic silver salt is silver benzotriazole, and said silver salt of said mercaptotriazole is the silver salt of Compound T-1,

A dispersion of a hydrophilic polymer binder or a water-dispersible polymer latex binder and one or more co-precipitate particles comprising first and second organic silver salts, said first organic silver salt comprising a silver salt of a nitrogen-containing heterocyclic compound containing an imino group, and said second organic silver salt being uniformly distributed throughout the volume of said particle and comprising a silver salt of a mercaptotriazole, and said hydrophilic polymer binder or said water-dispersible polymer latex binder being present in said dispersion in an amount of from about 2 to about 10 weight %,

• wherein said mercaptotriazole is represented by the following Structure (I):
• wherein R1 and R2 independently represent hydrogen, an alkyl group, an alkenyl group, a cycloalkyl group, an aromatic or non-aromatic heterocyclyl group, an amino or amide group, an aryl group, or a Y1—(CH2)k— group wherein Y1 is an aryl group or an aromatic or non-aromatic heterocyclyl group, and k is 1–3,
• or R1 and R2 taken together can form a 5- to 7-membered aromatic or non-aromatic nitrogen-containing heterocyclic ring,
• or still again, R1 or R2 can represent a divalent linking group linking two mercaptotriazole groups, and
• R2 may further represent carboxy or its salts,
• provided that R1 and R2 are not simultaneously hydrogen, and when R1 is an unsubstituted phenyl group, R2 is not hydrogen.