Single-part bleach-fixing composition and method of processing

An aqueous single-part photographic bleach-fixing composition that has a pH of from about 4.7 to about 5.3 and comprises:

• from about 0.1 to about 0.8 mol/l of an iron ammonium-ligand photographic bleaching agent that comprises at least 98 mol % of ferric ammonium-ethylenediaminetetraacetic acid, ferric ammonium-ethylenediaminedisuccinic acid, or ferric ammonium-1,3-propylenediaminetetraacetic acid, based on total iron, or mixtures thereof, as the photographic bleaching agent(s),
• from about 0.1 to about 2 mol/l of a thiosulfate as the sole photographic fixing agent,
• from about 0.01 to about 10 mmol/l of
• from about 0.01 to about 2 mol/l of sulfite ions that are sufficient to convert at least 75 mol % of said ferric ion to ferrous ion within 30 days at 20 to 45° C.,
• wherein at least 95 mol % of the total ammonium and alkali metal cations in said bleach-fixing composition are ammonium ions, and said bleach-fixing composition is substantially free of phosphates, polyphosphates, polyphosphonates, nitrates, and bromide ions.

A method of providing a color photographic image comprising contacting a color developed photographic color paper with an aqueous single-part photographic bleach-fixing composition, diluted or undiluted, that has a pH of from about 4.4 to about 6.5 and comprises:

• at least 0.1 mol/l of an iron ammonium-ligand photographic bleaching agent that comprises at least 95 mol % a ferric ammonium-ligand photographic bleaching agent, based on total iron, provided that the ligand in said bleaching agent is not diethylenetriaminepentaacetic acid,
• at least 0.1 mol/l of a thiosulfate as the sole photographic fixing agent, and
• sulfite ions present in an amount sufficient to convert at least 50 mol % of said ferric ammonium-ligand photographic bleaching agent to ferrous ammonium-ligand compound within 30 days at 20 to 45° C.,
• wherein at least 90 mol % of the total ammonium and alkali metal cations in said bleach-fixing composition are ammonium ions,
• said contacting being carried out for less than 60 seconds.

A method of providing a color photographic image comprising:

• (A) color developing a photographic color paper, and
• (B) contacting said color developed photographic color paper with an aqueous single-part photographic bleach-fixing composition, diluted or undiluted, that has a pH of from about 4.7 to about 5.8 and comprises:
• from about 0.1 to about 0.8 mol/l of an iron ammonium-ligand photographic bleaching agent that comprises at least 98 mol % of ferric ammonium-ethylenediaminetetraacetic acid, ferric ammonium-ethylenediaminedisuccinic acid, or ferric ammonium-1,3-propylenediaminetetraacetic acid, based on total iron, or mixtures thereof, as the photographic bleaching agent(s),
• from about 0.1 to about 2 mol/l of a thiosulfate as the sole photographic fixing agent,
• from about 0.01 to about 10 mmol/l of
• from about 0.01 to about 2 mol/l of sulfite ions that are sufficient to convert at least 75 mol % of said ferric ion to ferrous ion within 30 days at 20 to 45° C.,
• wherein at least 95 mol % of the total ammonium and alkali metal cations in said bleach-fixing composition are ammonium ions, and said bleach-fixing composition is substantially free of phosphates, polyphosphates, polyphosphonates, nitrates, and bromide ions,
• said contacting being carried out for less than 60 seconds.

A method of providing a stabilized single-part bleach-fixing composition that has a pH of from about 4.4 to about 5.4 and at least 50 mol % ferrous ammonium-ligand compound, based on total iron concentration, said method comprising mixing at least the following components (a), (b), and (c):

• (a) at least 0.1 mol/l of an iron ammonium-ligand photographic bleaching agent that comprises at least 95 mol % a ferric ammonium-ligand photographic bleaching agent, based on total iron, provided that the ligand in said bleaching agent is not diethylenetriaminepentaacetic acid,
• (b) at least 0.1 mol/l of a thiosulfate as the sole photographic fixing agent, and
• (c) sulfite ions in an amount sufficient to convert at least 50 mol % of said ferric ammonium-ligand photographic bleaching agent to ferrous ammonium-ligand compound within 30 days at 20 to 45° C.,
• provided that at least 90 mol % of the total ammonium and alkali metal cations mixed into said bleach-fixing composition are ammonium ions, and substantially no phosphates, polyphosphates, polyphosphonates, nitrates, or bromide ions are mixed into said bleach-fixing composition.

A method of converting ferric ions to ferrous ions in a composition comprising:

• A) mixing at least the following components (a), (b), and (c):
• (a) at least 0.1 mol/l of an iron ammonium-ligand photographic bleaching agent that comprises at least 95 mol % a ferric ammonium-ligand photographic bleaching agent, based on total iron, provided that the ligand in said bleaching agent is not diethylenetriaminepentaacetic acid,
• (b) at least 0.1 mol/l of a thiosulfate as the sole photographic fixing agent, and
• (c) sulfite ions,
• B) holding said mixture of (a), (b), and (c) for up to 30 days at 20 to 45° C.,
• provided that at least 90 mol % of the total ammonium and alkali metal cations mixed into said bleach-fixing composition are ammonium ions, and substantially no phosphates, polyphosphates, polyphosphonates, nitrates, or bromide ions are mixed into said bleach-fixing composition, and
• further provided that said sulfite ions are present in an amount sufficient to convert at least 50 mol % of said ferric ammonium-ligand photographic bleaching agent to ferrous ammonium-ligand compound under the conditions of step B.