[0001] This invention relates in general to color photography and in particular to methods
and compositions useful in the processing of color reversal photographic elements.
More particularly, this invention relates to a bleach regenerator composition, and
its use in the processing of the noted elements.
[0002] Multicolor, multilayer photographic elements are well known in the art. Such materials
generally have three different selectively sensitized silver halide emulsion layers
coated on one side of a single support. Each layer has components useful for forming
a particular color in an image. Typically, they utilize color forming couplers that
form yellow, magenta and cyan dyes in the sensitized layers during processing.
[0003] After color development, it is necessary to remove the silver image that is formed
coincident with the dye image. This can be done by oxidizing the silver using a suitable
oxidizing agent, commonly referred to as a bleaching agent, followed by dissolving
the silver halide so formed using what is known as a fixing agent.
[0004] A commercially important process intended for use with color reversal photographic
elements that contain color couplers in the emulsion layers, or layers contiguous
thereto, uses the following sequence of processing steps: first developing, washing,
reversal bath, color developing, bleaching, fixing, washing and stabilizing.
[0005] In the past, in continuous processing methods, including processing of reversal color
materials, the various processing solutions have been discarded after use. However,
more recently, used processing solutions have been collected and reused, at least
in part because of the environmental problems the waste solutions create, as well
as the high costs in collection and discard of the solutions. Thus, used solutions
have been reused by adding them to the processing baths as "replenishers" to the various
solutions. Considerable efforts are being carried out in the industry to find ways
to regenerate the components of the waste solutions so they can be reused as replenishers,
further reducing waste streams. For example, a bleach replenishing composition is
added to the bleach tank to keep the necessary components at the appropriate levels.
This bleach replenisher can be composed of, in part, bleach composition overflow.
[0006] As environmental needs increase in various countries, the industry is striving to
find ways to further reduce photoprocessing effluent from the various processing baths.
Thus, efforts have been made to regenerate the bleaching solution overflow and to
supply the regenerated replenisher solution to the bleach tank as the replenishment
solution. One known bleach regenerator solution for reversal color processes is sold
by Tetenal of Germany (sold as Tetenal Bleachbath E6/E6AR BL-RCY), which has a pH
of 7, and contains a relatively high bromide ion concentration (approximately 190-210
g/l).
[0007] There is also a desire in the industry to use a more concentrated bleach regenerator
so more bleaching solution overflow can be utilized to make the bleach replenisher,
thereby reducing effluent even further. The commercial product available from Tetenal,
however, has limited shelf life stability at its "neutral" pH. It was considered that
its pH might be lowered to increase stability, but when this was done, its solubility
was decreased and precipitation resulted after several days. Another problem with
the commercial Tetenal regenerator solution is that when acid is added to it to lower
its pH to the level needed for converting it to a regenerated replenisher, the bleaching
capacity of the resultant bleach tank solution is degraded.
[0008] There is a need therefore for a more stable bleach regenerator composition that can
be used in highly concentrated form to provide a regenerated bleach replenisher at
lower pH.
[0009] The problems noted above have been overcome using a method for processing a reversal
color silver halide photographic element comprising:
A) bleaching an imagewise exposed, color developed reversal color silver halide photographic
element in a bleaching tank with a bleaching composition comprising a complex of ferric
ethylenediaminetetraacetic acid as the bleaching agent,
B) supplying a bleach replenisher to the bleaching tank to result in an overflow of
used bleaching composition from the bleaching tank,
C) mixing at least 50% of the overflow, in at least a 1:1 volume ratio, with a bleach
regenerator composition to obtain a regenerated bleach replenisher,
the bleach regenerator composition having a pH of from 6.0 to 6.5, and comprising
a total bromide ion concentration of at least 210 g/l, and complex of ferric ion and
ethylenediaminetetraacetic acid, the ferric ion being present in an amount of at least
50 g/l,
D) adjusting the pH of the regenerated bleach replenisher prepared in step C to from
5.4 to 5.6, and
E) replenishing the bleaching composition of step A in the bleaching tank with the
pH adjusted regenerated bleach replenisher prepared in step D, using a bleach replenishment
rate of less than or equal to 215 ml/m2.
[0010] This invention also provides a bleach regenerator composition characterized as having
a pH of from 6.0 to 6.5, and comprising a total bromide concentration of at least
210 g/l, and a complex of ferric ion and ethylenediaminetetraacetic acid, the ferric
ion being present in an amount of at least 50 g/l.
[0011] The present invention effectively provides a bleach regenerator composition for processing
reversal color silver halide photographic materials. The bleach regenerator composition
is more stable and stays in solution even at lower pH for extended periods of time.
The composition is highly concentrated, for example, in the ferric ion concentration,
so that more bleach overflow can be used to form the bleach replenisher.
[0012] These advantages are achieved by using a bleach regenerator composition at considerably
lower pH, that is, 6.0-6.5, and thus stability is improved. However, in order to maximize
the concentration of the components, the level of bromide salt and hydrobromic acid
have been adjusted to provide a reformulated and improved composition.
[0013] A wide variety of reversal color photographic elements can be used in the practice
of the present invention. A detailed description of such materials is found, for example,
in
Research Disclosure, publication 36544, pages 501-541 (September, 1994). This reference will be referred
to hereinafter as "
Research Disclosure". More details such elements are provided herein below.
[0014] Reversal color photographic elements utilized in the practice of this invention are
typically comprised of a support having on one side thereof a plurality of photosensitive
silver halide emulsion layers. The photosensitive layers can contain any of the conventional
silver halides as the photosensitive material, for example, silver chloride, silver
bromide, silver bromoiodide, silver chlorobromide, silver chloroiodide, silver chlorobromoiodide,
and mixtures thereof. Useful support materials include cellulose acetate film, polyvinylacetal
film, polycarbonate film, polystyrene film, polyethylene terephthalate film, and the
like. The silver halide is dispersed within a suitable hydrophilic colloid such as
gelatin or derivatives thereof. The silver halide emulsion layers can contain a variety
of well-known addenda, including but not limited to, chemical sensitizers, development
modifiers and antifoggants.
[0015] As explained above, a well-known color reversal process of the prior art utilizes
a first developer, a reversal bath, a color developer, a conditioning solution, a
bleach bath, a fixing bath and a stabilizer bath. Alternatively, the stabilizer bath
can be replaced with a typical wash or rinse solution, and a "prebleach" or "conditioner"
bath is used for stabilizing the color image after color development and prior to
bleaching. The components that are useful in each of such baths are well known in
the photographic art. The improved process of this invention can utilize the same
baths.
[0016] The first developer generally contains a black-and-white developing agent or a mixture
thereof. Useful developing agents include, but are not limited to, dihydroxybenzene
developing agents (such as hydroquinone), 3-pyrazolidone developing agents (such as
1-phenyl-3-pyrazolidone), and aminophenol developing agents (such as paraaminophenol).
In addition to the developing agent, the first developer typically contains other
agents such as preservatives, sequestering agents, restrainers, antifoggants, buffers
and silver halide solvents.
[0017] The reversal bath generally contains a nucleating agent, such as a boron compound
or a chelated stannous salt (such as stannous chloride) that functions as a reducing
agent, as well as antioxidants, buffers, fungicides and sequestering agents.
[0018] In addition to an aromatic primary amino color developing agent, the color developing
bath typically contains sequestering agents, buffering agents, preservatives, antioxidants,
competing couplers and silver halide solvents.
[0019] Particularly useful aromatic primary amino color developing agents are the
p-phenylenediamines and especially the N,N-dialkyl-
p-phenylenediamines in which the alkyl groups or the aromatic nucleus can be substituted
or unsubstituted. Examples of useful
p-phenylenediamine color developing agents include, but are not limited to, N,N-diethyl-
p-phenylenediamine monohydrochloride, 4-N,N-diethyl-2-methylphenylenediamine monohydrochloride,
4-(N-ethyl-N-2-methanesulfonylaminoethyl)-2-methylphenylenediamine sesquisulfate monohydrate,
4-(N-ethyl-N-2-hydroxyethyl)-2-methyl-phenylenediamine sulfate, 4-N,N-diethyl-2,2'-methanesulfonylaminoethylphenylenediamine
hydrochloride, and others readily apparent to a skilled worker in the art.
[0020] The essential component of the bleaching bath is a bleaching agent that converts
metallic silver to silver ions. Other common components of the bleaching bath include
halides, sequestering agents and corrosion inhibitors. One or more ammonium or alkali
metal salts of a ferric complex of ethylenediaminetetraacetic acid are useful as bleaching
agents in this invention.
[0021] The fixing bath converts all silver halide into soluble silver complexes that diffuse
out of the emulsion layers. Fixing bath retained within the layers of the photographic
element is removed in a subsequent water washing step. Thiosulfates, including ammonium
thiosulfate and alkali metal thiosulfates (such as sodium thiosulfate and potassium
thiosulfate), are particularly useful as fixing agents. Other components of the fixing
bath include preservatives and sequestering agents.
[0022] A wide variety of different color reversal processes are well known in the art. For
example, a single color developing step can be used when the coupling agents are incorporated
in the photographic element or three separate color developing steps can be used in
which coupling agents are included in the developing solutions. The reversal step
can be carried out by use of a reversal bath, by a reexposure step, or by incorporating
a fogging agent in the color developing bath. In order to provide shorter processing
times, bleaching and fixing can be combined in a single step (known as a bleach-fixing
step).
[0023] Stabilization solutions are also known in the art for use in reversal photoprocessing
methods. Such solutions generally include formaldehyde or an equivalent material to
stabilize magenta dye image. Further details of such solutions are provided, for example,
in US-A-4,786,583.
[0024] Alternatively and preferably, stabilization is achieved by using a prebleach or conditioning
solution after color development and prior to bleaching. The various details of such
solutions and their use are provided, for example, in US-A-4,921,779, US-A-4,975,356,
US-A-5,037,725, and US-A-5,334,493. Other optional features of useful conditioning
solutions are secondary amines.
[0025] The bleaching composition used in this invention comprises a complex of ferric ion
and ethylenediaminetetraacetic acid in a suitable concentration. The amount of iron(III)
is generally from 50 to 58 g/l. One or more salts of the complex can be used if desired.
The bleaching composition is supplied to the bleach tank in a suitable rate to result
in an overflow of used bleaching solution from the bleaching tank. Generally, the
rate of supply is less than or equal to 215 ml/m
2, and preferably from 140 to 215 ml/m
2.
[0026] At least 50%, preferably from 50 to 80%, and more preferably from 50 to 75%, of the
bleaching composition overflow is mixed with the bleach regenerator composition to
obtain a regenerated bleach replenisher. The mixing is carried out in at least a 1:1
volume ratio of bleaching composition overflow to bleach regenerator composition,
and up to 9:1. Preferably, the volume ratio of mixing is from 1:1 to 3:1.
[0027] After mixing, the pH of the regenerated bleach replenisher is adjusted downward to
from 5.4 to 5.6 by adding a suitable amount of an organic or inorganic acid, such
as acetic acid, succinic acid, maleic acid, tartaric acid, malonic acid, or nitric
acid. Acetic acid is preferred. The amount of acid to be added could be readily determined
by routine experimentation, depending upon the pH of the regenerated bleach replenisher
and the particular acid used. For acetic acid, the amount added is generally from
10 to 20 ml/l. One advantage of this invention is that less acid needs to be added
to the regenerated bleach replenisher than to conventional regenerator solutions.
[0028] The pH adjusted regenerated bleach replenisher is then added to the bleaching tank
as the "bleach replenisher" at a bleach replenishment rate of less than or equal to
215 ml/m
2, and preferably at from 140 to 215 ml/m
2.
[0029] The bleach regenerator composition used in the method of this invention has a pH
of from 6.0 to 6.5 (preferably from 6.0 to 6.2). It includes the bleaching agent,
a ferric ion complex of ethylenediaminetetraacetic acid in an amount to provide ferric
ion in an amount of at least 50 g/l, and preferably at from 50 to 58 g/l. Ferric ion
can be supplied for the complex as a suitable ferric salt or oxide, such as ferric
nitrate, ferric sulfate, ferric oxide or ferric bromide. Ferric oxide or ferric nitrate
is preferred. The complex can be provided as an ammonium or alkali metal salt, as
well as the free acid.
[0030] Also included in the bleach regenerator composition are one or more sources of bromide
ion such that the total bromide ion is present in an amount of at least 210 g/l, preferably
at from 215 to 240 g/l, and most preferably at from 220 to 240 g/l. Preferably, total
bromide ion is provided by a combination of hydrobromic acid and a bromide salt (such
as sodium bromide, potassium bromide, ammonium bromide or lithium bromide). More preferably,
at least 80%, more preferably from 80 to 97%, of the total bromide ion is provided
from the bromide salt, and the remainder from the hydrobromic acid. Ammonium bromide
is most preferred.
[0031] One or more corrosion inhibitors can also be included in the bleach regenerator composition
if desired at suitable concentrations. Preferably, such corrosion inhibitors include,
but are not limited to, the potassium salts of nitrate, silicate, chromate and phosphate.
Hexamethylenetetraamine and benzotriazole can also be used. Potassium nitrate is preferred.
[0032] A preferred embodiment of this invention is a bleach regenerator composition having
a pH of from 6.0 to 6.2, and comprising:
a) a total bromide ion concentration of from 220 to 240 g/l provided by a combination
of hydrobromic acid and a bromide salt, the amount from the bromide salt being from
80 to 97% of the total bromide ion,
b) a complex of ferric ion and ethylenediaminetetraacetic acid, the ferric ion being
present in an amount of from 50 to 58 g/l, and
c) a corrosion inhibitor.
[0033] The photographic elements processed in the practice of this invention can be single
or multilayer color elements. Multilayer color elements typically contain dye image-forming
units sensitive to each of the three primary regions of the visible spectrum. Each
unit can be comprised of a single emulsion layer or multiple emulsion layers sensitive
to a given region of the spectrum. The layers of the element can be arranged in any
of the various orders known in the art. In an alternative format, the emulsions sensitive
to each of the three primary regions of the spectrum can be disposed as a single segmented
layer. The elements can also contain other conventional layers such as filter layers,
interlayers, subbing layers, overcoats and other layers readily apparent to one skilled
in the art. A magnetic backing can be used as well as conventional supports.
[0034] Considerable details of the element structure and components, and suitable methods
of processing various types of elements are described in
Research Disclosure, noted above. All types of emulsions can be used in the elements, including but not
limited to, thin tabular grain emulsions, and either positive-working or negative-working
emulsions.
[0035] The present invention is particularly useful to process imagewise exposed and developed
photographic elements containing arylpyrazolone type magenta dye forming color couplers.
Such color couplers are well known in the art. One such compound is described in US-A-5,037,725.
Useful cyan dye and yellow dye forming couplers that can be incorporated into such
elements are also well known.
[0036] The elements are typically exposed to suitable radiation to form a latent image and
then processed as described above to form a visible dye image.
[0037] The bleaching step described above is generally carried out for from 4 to 8 minutes,
but longer times can be used if desired. Preferably, the bleaching time is 6 minutes.
The temperature at which bleaching is carried out is generally above room temperature,
for example from 30 to 40 °C.
[0038] Processing according to the present invention can be carried out using conventional
deep tanks holding processing solutions. Alternatively, it can be carried out using
what is known in the art as "low volume thin tank" processing systems having either
vertical rack and tank or horizontal automatic tray designs. Such processing methods
and equipment are described, for example, in US-A-5,436,118 and publications cited
therein.
[0039] The following examples are provided for illustrative purposes only and are not intended
to be limiting in any way. Unless otherwise indicated, all percentages are by volume.
Example 1: Preferred Bleach Regenerator Composition
[0040] A preferred bleach regenerator composition of this invention was prepared by mixing
the following in water (added to make 1 liter total): commercially available 1.56
molar ammonium ferric-ethylenediaminetetraacetic acid (788 g), hydrobromic acid (61.5
g), ammonium bromide (243.9 g) and potassium nitrate (67 g). The final pH was 6.0-6.2.
Example 2: Preferred Regenerated Bleach Replenisher Composition & Comparison
[0041] The bleach regenerator composition of Example 1 was mixed with seasoned conventional
color reversal bleach composition overflow comprising 1.56 molar ammonium ferric-ethylenediaminetetraacetic
acid bleaching agent (277 g/l), bromide ion from various salts (73.8 g/l), and potassium
nitrate (25 g/l). The volume ratio of bleach composition (which is comparable to bleach
overflow) to bleach regenerator composition was 1:1. The resulting regenerated bleach
replenisher had a pH of 5.95-6.1. The pH was then adjusted downward to 5.4-5.6 by
adding acetic acid (18 ml/l) to provide a pH adjusted regenerated bleach replenisher
that can be directly added to a bleach bath to process reversal color silver halide
photographic materials.
[0042] As noted above, the amount of acetic acid needed to adjust the pH of the regenerated
bleach replenisher was only 18 ml/l. However, when the commercially available Tetenal
Bleachbath E6/E6AR BLRCY regenerator solution was used in a similar fashion, it was
necessary to add acetic acid at 30 ml/l in order to obtain the desired pH. Thus, clearly
the present invention allows one to reduce the amount of acid in preparing a bleach
replenisher, and this acid reduction provides advantages as noted above.
Example 3: Processing Reversal Color Photographic Elements
[0043] The regenerated bleach replenisher compositions of this invention were evaluated
in otherwise conventional reversal color photographic processing.
[0044] The invention was used to process samples of a conventional color reversal photographic
films (available from Eastman Kodak Company) using the following processing protocol.
This film contained a conventional 1-aryl-5-pyrazolone magenta color coupler in one
of the emulsion layers.
Processing Protocol: |
6 minutes |
First Development* |
2 minutes |
Water wash |
2 minutes |
Reversal bath** |
6 minutes |
Color development*** |
2 minutes |
Prebleach@ |
6 minutes |
Bleaching**** |
4 minutes |
Fixing# |
4 minutes |
Water wash |
30 seconds |
Final wash## |
20 minutes |
Drying |
* Using conventional Process E-6 KODAK™ First Developer. |
** Using conventional Process E-6 KODAK™ Reversal Bath. |
*** Using conventional Process E-6 KODAK™ Color Developer. |
@ Using conventional Process E-6 KODAK™ Prebleach and Replenisher. |
**** Using conventional Process E-6 KODAK™ Bleach (Ferric-EDTA bleaching agent). |
# Using conventional Process E-6 KODAK™ Fixer. |
## Using conventional Process E-6 KODAK™ Final Rinse. |
[0045] The method of this invention was carried out by taking at least 50% of the bleach
bath overflow and mixing it (at a 1:1 volume ratio) with the bleach regenerator composition
of Example 1. This mixing was carried out for 3 minutes at 20-25 °C in a separate
vessel. The mixture pH of 5.9-6.1 was then adjusted downward by adding acetic acid
as described in Example 2, and the adjusted mixture was then added to the bleach bath
as a replenisher for the process. This method was carried out for at least 4 bleach
tank turn-overs, or for at least 330 m
2 of processed reversal color photographic film. The results of processing were highly
acceptable. That is, use of the noted regenerated bleach composition provided highly
acceptable processing of the film.
Examples 4-6: Effects of pH in Bleach Regenerator Composition
[0046] Experiments were carried out to show the critical importance of the bleach regenerator
composition having a pH of from 6.0 to 6.5.
[0047] Several regenerator compositions like that described in Example 1 above were subjected
to keeping tests to see if crystallization or precipitation would occur. The various
compositions had components like Example 1 and various pH values as shown in Table
I below.
[0048] The results of the keeping tests are shown in Table I for the various compositions.
Column 1 lists the keeping temperatures (from -18 to +21 °C) at which the compositions
were stored for 14 days. Column 2 shows when the crystallization results were observed
(at room temperature) after the compositions were removed from the keeping environment,
that is "Observation Time After Removal". Thus, samples of each composition were observed
immediately ("0" time), 24 hours, and 11 days after they were removed from the keeping
environment. Crystals of ammonium ferric ethylenediaminetetraacetic acid complex were
measured by visual inspection and identified by Fourier Transform Infrared (FTIR)
spectroscopy.
[0049] The results indicate that best time and temperature stability for the composition
is achieved when the pH is at least 6.0. It is noted that Control C, while being stable
at a pH above 6.5, is undesirable because at such high pH, unacceptably high amounts
of acid must be added to the regenerated bleach replenisher to lower the pH to an
acceptable level before it can be added to the bleach bath as replenisher.
[0050] In addition, several bleaching compositions were subjected to high temperature (49
°C) keeping for 12 days. Examples 4 and 6 were compared to three "Control" bleaching
compositions outside this invention, including Control C identified above. Control
D was a commercial Process E-6 (reversal) Bleach Replenisher containing ferric ethylenediaminetetraacetic
acid bleaching agent and having pH 5.4. Control E was a commercial highly concentrated
(1.56 mol/l) ammonium ferric ethylenediaminetetraacetic acid, KODAK BL-1, having pH
7.0.
[0051] The results of ferrous ion build-up (g/l) after keeping are listed in Table II below.
It was observed that the pH dropped in all compositions during the high temperature
keeping test, but subsequent freezing of the compositions did not cause precipitation.
TABLE II
Composition |
pH |
Ferrous Ion Buildup (g/l) |
Control D |
5.4 |
7 |
Example 4 |
6.0 |
33 |
Example 6 |
6.5 |
37 |
Control C |
6.9 |
40 |
Control E |
7.0 |
60 |
[0052] To determine if the change in pH after keeping might diminish bleaching performance
of the regenerator compositions, Examples 4 and 6 and Control C were formulated into
working strength bleaching solutions, and were then used to bleach three different
commercially available reversal color films: KODAK EKTACHROME™ 400 HC Film, KODAK
EKTACHROME™ ELITE™ 100 Film and KODAK EKTACHROME™ 64 Professional Film. A solution
made from a pH 6.5 concentrate, which had been kept at room temperature, was used
as the "Standard" solution. All compositions were brought to the same total iron level
and then aerated to oxidize any ferrous ion to ferric ion. Once this was completed,
the compositions were all pH adjusted to the standard bleaching pH of 5.8
[0053] Table III below lists the "bleach clear times" for each regenerator composition tested.
"Bleach clear time" refers to the time at which all metallic silver has been converted
to silver halide for subsequent dissolution and removal in the following fixing step.
The results indicate that a regenerator composition pH of 6.0-6.5 is desired for improved
composition keeping.
TABLE III
Composition |
Bleach Clear Time (seconds) |
Standard |
252 |
Example 4 |
313 |
Example 6 |
342 |
Control C |
337 |
Example 7: Effect of Bromide Level in Bleach Regenerator Composition
[0054] Experiments were also carried out to show the effect of bromide ion concentration
in the bleach regenerator composition of this invention.
[0055] A 2
4 factorial experiment with optimized "aims" was carried out around the chemical ingredients
of a conventional Process E-6 bleaching solution. One of those components is bromide
ion. The level of bromide ion was varied while all other components were kept at optimized
levels for processing two different commercially available color reversal photographic
films, and the bleach "clear time" (seconds to convert all silver metal to silver
halide) was determined. The optimized or "aim" level for bromide ion in the bleaching
solution was considered to be 73.4 g/l. The following Table IV lists the data obtained.
TABLE IV
Bromide Ion (g/l) |
Predicted Clear |
Bleaching Time (seconds |
Average Δ Clear Time (seconds) |
|
Film #1 |
Film #2 |
|
65.8 |
301 |
309 |
44 |
73.4 (aim) |
273 |
282 |
81.0 |
259 |
263 |
[0056] As one can see from these data, the average reduction in "clear time" during bleaching
for processing the two films from varying the bromide ion level, was 44 seconds. This
was surprising to us. It had been previously thought that because the bromide ion
in conventional replenisher is relatively high (145-150 g/l), that the amount of bromide
ion "used" during bleaching would not have a significant impact on the rate of bleaching
(and thus, the bleaching "clear time"). These experiments proved otherwise and showed
the significant potential magnitude of the impact from increased bromide ion concentration.
[0057] We discovered that with reuse or regeneration of the bleaching solution (in which
case, the bromide ion is "used up" repeatedly and tank concentration would drop below
levels seen in conventional replenishment), additional bromide ion must be added to
compensate for the usage, as well as for the deterioration in bleaching rate (and
thus, bleach "clear time") due to additional build-up of carryover products.
[0058] Bleach replenisher provides three benefits to the tank bleaching solution:
1) dilution of chemicals carried in and undesirable chemicals produced in chemical
reactions,
2) addition of chemicals, such as bromide ion, to make up for those used in chemical
reactions necessary for bleaching, and
3) make up for chemicals that are diluted by carryover or carried out into the next
solution (that is the fixing solution).
[0059] The conventional Tetenal Process E-6 bleach regenerator has bromide ion levels which
account only for the first and third benefits noted above. We have found that this
is inadequate, and that the level of bromide ion in the bleach regenerator must also
be adjusted for bromide ion used up in the bleaching reaction (approximately 14-18
g/l of replenisher when processing elements containing 4.3-5.4 g silver/m
2). Thus, we determined that the level of bromide ion needed to be increased in the
regenerator composition that is used to provide a regenerated bleach replenisher,
and the present invention reflects that fact.
1. Bleich-Auffrischerzusammensetzung, dadurch gekennzeichnet, daß sie einen pH-Wert von
6,0 bis 6,5 und eine Gesamt-Bromidionen-Konzentration von mindestens 210 g/l hat und
einen Komplex von Ferriionen und Ethylendiamintetraessigsäure aufweist, wobei die
Ferriionen in einer Menge von mindestens 50 g/l vorliegen.
2. Zusammensetzung nach Anspruch 1 mit einem pH-Wert von 6,0 bis 6,2.
3. Zusammensetzung nach einem der Ansprüche 1 und 2 mit einer Gesamt-Bromidionen-Konzentration
von 215 bis 240 g/l.
4. Zusammensetzung nach einem der Ansprüche 1 bis 3, in der die gesamten Bromidionen
bereitgestellt werden durch eine Kombination aus einer Bromwasserstoffsäure und einem
Bromidsalz, wobei die Bromidionen, die durch das Bromidsalz bereitgestellt werden,
mindestens 80 % der Gesamt-Bromidionen ausmachen.
5. Zusammensetzung nach einem der Ansprüche 1 bis 4, in der die Ferriionen in einer Menge
von 50 bis 58 g/l vorliegen.
6. Zusammensetzung nach einem der Ansprüche 1 bis 5, die ferner einen Korrosionsinhibitor
enthält.
7. Verfahren zur Entwicklung eines farbphotographischen Silberhalogenid-Umkehrelementes,
bei dem man:
A) ein bildweise exponiertes, farbentwickeltes, farbphotographisches Silberhalogenid-Umkehrelement
in einen Bleichtank mit einer Bleich-Zusammensetzung bleicht, die einen Komplex aus
Ferriethylendiamintetraessigsäure als Bleichmittel enthält, bei dem man
B) dem Bleichtank einen Bleich-Auffrischer zuführt, um einen Überlauf an gebrauchter
Bleich-Zusammensetzung aus dem Bleichtank herbeizuführen, bei dem man
C) mindestens 50 % des Überlaufs in einem Volumenverhältnis von mindestens 1:1 mit
der Bleich-Auffrischerzusammensetzung nach einem der Ansprüche 1 bis 6 vermischt,
um einen regenerierten Bleich-Auffrischer zu erzeugen, bei dem man
D) den pH-Wert des regenerierten Bleich-Auffrischers, hergestellt in Stufe C, auf
5,4 bis 5,6 einstellt, und bei dem man
E) die Bleich-Zusammensetzung von Stufe A in dem Bleichtank mit dem regenerierten
Bleich-Auffrischer mit eingestelltem pH-Wert, hergestellt in Stufe D, auffrischt,
unter Anwendung einer Bleich-Auffrisch-Geschwindigkeit von weniger als oder gleich
215 ml/m2.
8. Verfahren nach Anspruch 7, bei dem die Bleich-Auffrisch-Geschwindigkeit bei 140 bis
215 ml/m2 liegt.
9. Verfahren nach einem der Ansprüche 7 oder 8, bei dem 50 bis 80 % des Bleichtank-Überlaufs
mit der Bleich-Auffrischerzusammensetzung in Stufe C vermischt werden.
10. Verfahren nach einem der Ansprüche 7 bis 9, bei dem das Volumenverhältnis des Bleichtank-Überlaufs
zur Bleich-Auffrischerzusammensetzung bei bis zu 9:1 liegt.
11. Verwendung der Bleich-Auffrischerzusammensetzung nach einem der Ansprüche 1 bis 6
für die Entwicklung von farbphotographischen Silberhalogenid-Umkehrmaterialien.
1. Composition régénératrice de blanchiment caractérisée par un pH compris entre 6,0
et 6,5 et comprenant une concentration totale en ion bromure d'au moins 210 g/l et
un complexe d'ion ferrique et d'acide éthylènediaminetétraacétique, l'ion ferrique
étant présent en une quantité d'au moins 50 g/l.
2. Composition selon la revendication 1 ayant un pH compris entre 6,0 et 6,2.
3. Composition selon l'une ou l'autre des revendications 1 et 2 ayant une concentration
totale en ion bromure comprise entre 215 et 240 g/l.
4. Composition selon l'une quelconque des revendications 1 à 3, dans laquelle la quantité
totale d'ion bromure est formée d'une combinaison d'un acide bromhydrique et d'un
sel de bromure, l'ion bromure du sel de bromure représentant au moins 80% de la quantité
totale d'ion bromure.
5. Composition selon l'une quelconque des revendications 1 à 4, dans laquelle l'ion ferrique
est présent en une quantité comprise entre 50 et 58 g/l.
6. Composition selon l'une quelconque des revendications 1 à 5 comprenant en outre un
inhibiteur de corrosion.
7. Procédé de traitement d'un élément photographique inversible en couleurs aux halogénures
d'argent comprenant :
A) le blanchiment d'un élément photographique inversible en couleurs aux halogénures
d'argent exposé conformément à l'image et développé dans un révélateur chromogène,
dans une cuve de blanchiment au moyen d'une composition de blanchiment comprenant
un complexe de l'éthylène diamine tétraacétate ferrique utilisé comme agent de blanchiment,
B) l'introduction d'une solution de renouvellement de blanchiment dans la cuve de
blanchiment pour créer un trop-plein de composition de blanchiment usagée provenant
de la cuve de blanchiment,
C) le mélange d'au moins 50% du trop-plein, selon un rapport en volume d'au moins
1:1, avec la composition régénératrice de blanchiment telle que revendiquée dans l'une
quelconque des revendications 1 à 6, pour obtenir une solution de renouvellement de
blanchiment régénérée,
D) l'ajustement du pH de la solution de renouvellement de blanchiment régénérée préparée
à l'étape C à un pH de 5,4 à 5,6, et
E) le renouvellement de la composition de blanchiment de l'étape A dans la cuve de
blanchiment au moyen de la solution de renouvellement de blanchiment régénérée dont
le pH a été ajusté préparée à l'étape D, en utilisant une vitesse de renouvellement
de la solution de blanchiment inférieure ou égale à 215 ml/m2.
8. Procédé selon la revendication 7, dans lequel la vitesse de renouvellement de la solution
de blanchiment est comprise entre 140 et 215 ml/m2.
9. Procédé selon l'une ou l'autre des revendications 7 ou 8, dans lequel on mélange de
50 à 80% du trop-plein de la cuve de blanchiment avec la composition régénératrice
de blanchiment de l'étape C.
10. Procédé selon l'une quelconque des revendications 7 à 9, dans lequel le rapport en
volume du trop-plein de la cuve de blanchiment à la composition régénératrice de blanchiment
peut aller jusqu'à 9:1.
11. Utilisation de la composition régénératrice de blanchiment revendiquée dans l'une
quelconque des revendications 1 à 6 pour le traitement des produits photographiques
inversibles en couleurs aux halogénures d'argent.