Radiation imagery chemistry: process – composition – or product th – Nonradiation sensitive image processing compositions or... – Bleach or intensification
Reexamination Certificate
2003-02-28
2004-03-09
Le, Hoa Van (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Nonradiation sensitive image processing compositions or...
Bleach or intensification
Reexamination Certificate
active
06703192
ABSTRACT:
FIELD OF THE INVENTION
In general, this invention relates to photography and to photographic processing compositions and methods used to provide color images in color photographic materials. In particular, it relates to a photographic bleaching composition containing a peracid bleaching agent and a specific polyphosphonic acid. It also relates to photographic processing kits and methods of use for the bleaching composition.
BACKGROUND OF THE INVENTION
The basic image-forming process of color silver halide photography comprises the exposure of a silver halide color photographic recording material to actinic radiation (such as light) and the manifestation of a useful image by wet chemical processing of the material. The fundamental steps of this wet processing include color development to reduce silver halide to silver and to produce dye images in exposed areas of the material. During or after bleaching to oxidize metallic silver to silver (I), the silver ion is generally removed by dissolving it in a silver solvent, commonly known as a fixing agent.
The most common bleaching agents for color photographic processing are complexes of ferric [Fe (III)] ion and various organic chelating ligands (such as aminopolycarboxylic acids), of which there are hundreds of possibilities, all with varying photographic bleaching abilities and biodegradability.
Less common bleaching agents are what are known as peracids including the most common peracid, hydrogen peroxide. These bleaching agents provide some advantages over the more common ferric ion-ligand complexes including reduced environmental concerns. Numerous publications describe peroxide, persulfate, and other peracid bleaching agents and their use in photographic processing. See for example U.S. Pat. No. 5,451,491 (Szajewski et al.), U.S. Pat. No. 5,460,924 (Buchanan et al.), U.S. Pat. No. 5,464,728 (Szajewski et al.), U.S. Pat. No. 5,508,151 (O'Toole et al.), U.S. Pat. No. 5,510,232 (O'Toole), U.S. Pat. No. 5,521,056 (Buchanan et al.), U.S. Pat. No. 5,538,834 (Buchanan et al.), U.S. Pat. No. 5,541,041 (Haye), U.S. Pat. No. 5,547,816 (Fyson et al.), U.S. Pat. No. 5,550,009 (Haye et al.), U.S. Pat. No. 5,554,491 (O'Toole et al.), U.S. Pat. No. 5,578,428 (Fyson), U.S. Pat. No. 5,614,355 (Haye et al.), U.S. Pat. No. 5,641,615 (Haye et al.), U.S. Pat. No. 5,641,616 (Haye et al), U.S. Pat. No. 5,656,416 (O'Toole et al.), U.S. Pat. No. 5,683,858 (Fyson), U.S. Pat. No. 5,691,118 (Haye), U.S. Pat. No. 5,691,112 (O'Toole), U.S. Pat. No. 5,763,147 (Haye et al.), and U.S. Pat. No. 5,773,202 (Haye et al.).
Throughout the photographic industry, there is a desire to provide photographic processing solutions that are safe and easy to use, photographically effective, and environmentally acceptable. One desirable property is that the solutions are not objectionable due to unpleasant odors. In addition, there is a need to stabilize some of the peracid bleaching agents that can decompose upon long-term storage or use and providing rapid bleaching.
Despite the many useful photographic bleaching solutions and processing methods known in the art, there is a continuing need for a highly effective photographic bleaching composition containing a peracid bleaching agent that has improved stability.
SUMMARY OF THE INVENTION
The present invention provides an advance in the photographic art with a composition for photographic bleaching comprising at least 0.005 mol/l of a peracid bleaching agent or a compound that generates or provides a peracid bleaching agent, and at least 0.00005 mol/l of a cyclicaminomethanediphosphonic acid or a salt thereof.
In preferred embodiments of this invention, a composition for photographic bleaching has a pH of from about 1 to about 11, and comprises:
from about 0.01 to about 3 mol/l of hydrogen peroxide or a compound that provides hydrogen peroxide as a photographic bleaching agent, from about 0.0001 to about 0.25 mol/l of morpholinomethanediphosphonic acid or a salt thereof, and optionally, one or more additional polyaminopolyphosphonic acids or salts thereof.
This invention also provides a photographic processing kit comprising:
A) a first composition comprising a peracid bleaching agent or a compound that generates or provides a peracid bleaching agent, and
B) a second composition comprising a cyclicaminomethanediphosphonic acid or a salt thereof.
These compositions in the kit can be in liquid or solid form.
In addition, a method of providing a color image comprises contacting a color photographic material with a composition for photographic bleaching comprising at least 0.005 mol/l of a peracid bleaching agent or a compound that generates or provides a peracid bleaching agent, and at least 0.00005 mol/l of a cyclicaminomethanediphosphonic acid or a salt thereof.
In preferred embodiments, a method of photographic processing comprises:
A) contacting a color photographic material with a color developing composition, and
B) contacting the color photographic material with a composition for photographic bleaching comprising at least 0.005 mol/l of a peracid bleaching agent or a compound that generates or provides a peracid bleaching agent, and at least 0.00005 mol/l of a cyclicaminomethanediphosphonic acid or a salt thereof.
This invention includes aqueous peracid bleaching compositions (solutions or compounds) containing peracids in combination with a cyclicaminomethanediphosphonic acid, such as morpholinomethanediphosphonic acid, alone or in combination with other sequestering agents at either acidic or alkaline pH conditions. These compositions have reduced odor and can be used for the bleaching of a wide variety of silver halide based photographic materials.
DETAILED DESCRIPTION OF THE INVENTION
Photographic bleaching is carried out according to the present invention in one or more steps using one or more peracid photographic bleaching agents as the first essential component of the bleaching composition. Such compounds include, but are not limited to, the hydrogen, alkali and alkaline earth salts of persulfate, peroxide, perchlorate, perborate, periodate, perphosphate, percarbonate, chlorate, bromate, iodate, and metaperiodate. These bleaching agents can be formulated as described, for example, in
Research Disclosure
September 1994, Item 36544 published by Kenneth Mason Publications, Ltd., Dudley House, 12 North Street, Emsworth, Hampshire PO10 7DQ, England (also available from Emsworth Design, 147 West 24th Street, New York, N.Y. 10011), and the patents listed in the “Background” above, all of which are incorporated herein by reference.
Especially useful peracids are peroxides, persulfates, and periodates. Sodium persulfate and hydrogen peroxide are most preferred bleaching agents.
Compounds that generate or provide a suitable peracid can be present in the compositions and kits of this invention. For examples, precursors of hydrogen peroxide are well known in the art and include, for example, perborates, perphosphates, percabonates, percarboxylates, and hydrogen peroxide urea. In addition, hydrogen peroxide can be generated within a solution by electrolysis.
The second essential component of the compositions and kits of this invention that appear to act as “stabilizing” compounds are cyclicaminomethanediphosphonic acid (and salts thereof), or mixtures thereof, as described in U.S. Pat. No. 4,873,180 (Marchesano et al.). “Cyclicamino” groups comprise 3- to 6-membered rings, including but not limited to substituted or unsubstituted aziridino, pyrrolidino, imidazolidino, piperidino, piperazino, isoindolino, and morpholino groups. The substituted or unsubstituted morpholino groups are preferred. Suitable substituents for the cyclicamino groups include, but are not limited to, alkyl groups having 1 to 4 carbon atoms, halo groups, nitro groups, cyano groups, aryl groups, alkoxy groups having 1 to 4 carbon atoms, aryloxy groups, sulfamoyl groups, acyloxy groups, acylamino groups, ureido groups, sulfonamido groups, hydroxy groups, and others that would be readily apparent to one skilled in the art f
Haye Shirleyanne E.
Huston Janet M.
Eastman Kodak Company
Le Hoa Van
Tucker J. Lanny
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