JPH09166855A - Component of bleaching and reproducing agent and method for processing inverted color photograph element using componentthereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to use a regenerated breach agent compsn. in an extremely concd. form and to stabilize more for providing a bleach replenishing liquid regenerated at lower pH. SOLUTION: This ferric-EDTA bleach regenerating agent compsn. mixed with a bleach overflow is capable of yielding the bleach replenishing liquid for reversal color silver halide photographic processing. The bleach regenerating agent compsn. has pH critically controlled to 6.0 to 6.5 and contains ferric ions in the total bromide ion concn. of >=210g/L and in the amt. of >=50g/L. At lest 50% of the bleach overflow and the bleach regenerating agent compsn. are mixed at least at a volumetric ratio of 1:1. After the pH is adjusted to 5.4 to 5.6, the replenishing liquid subjected to the pH adjustment is supplied to a bleaching tank in order to use the liquid in processing.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates generally to color photography, and more particularly to methods and compositions useful in processing color reversal photographic elements. More particularly, this invention relates to bleach regenerator compositions and methods of processing color reversal photographic elements using same.

[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 that are useful for forming the particular color in the image.
Typically they use color-forming couplers which form yellow, magenta and cyan dyes in the sensitizing layer during processing.

After color development it is necessary to remove the silver image which is formed at the same time as the dye image. It oxidizes silver using a suitable oxidizing agent commonly referred to as a bleach, and then the silver halide thus formed,
It can be carried out by dissolving using what is known as a fixing agent.

In a commercially important process intended for use in a color reversal photographic element containing a color coupler in the emulsion layer or a layer adjacent thereto, the following sequence of processing steps: first development, Washing, reversal bath, color development,
Use bleaching, fixing, washing and stabilizing.

Previously, in a continuous processing method involving the processing of reverse color materials, various processing solutions were discarded after use. However, more recently, due to the environmental concerns of waste solutions and the high cost of collecting and disposing of solutions, used processing solutions have been at least partially collected and reused. Therefore, the used solutions have been reused by adding them to the processing bath as "replenishers" for various solutions. Considerable efforts have been made in industry to reclaim the components of the effluent and thus reuse them as replenishers and further reduce the effluent flow rate. For example, a bleach replenishing composition is added to a bleaching tank to maintain the required ingredients at appropriate levels. The bleach replenisher may partially consist of a bleaching composition overflow.

Due to the increasing environmental demands in various countries, the industry is seeking to find ways to further reduce photographic processing effluent from various processing baths. Efforts have therefore been made to regenerate the bleach liquor overflow and supply the replenished replenisher regenerated to the bleach tank as the replenisher. One known bleach regenerant solution for reversal color processing is sold by Tetenal GmbH of Germany (Tetena
Bleachbath E6 / E6AR BL-RCY), which has a pH of 7 and contains a relatively high bromide ion concentration (about 190-210 g / L).

[0007]

A greater amount of bleach liquor overflow can be used to produce a bleach replenisher, thereby providing a more concentrated bleach regenerator so as to further reduce waste liquor. There is an industry need for use. However, Tetena
The commercial product available from L.S. has a limited shelf life stability at its "neutral" pH. It was thought to lower its pH in order to increase its stability, but when it did so, its solubility decreased and precipitation occurred after a few days. Other problems with commercial Tetenal regenerant solutions include:
The bleaching capacity of the resulting bleaching tank solution is diminished when an acid is added to it to reduce its pH to the level required to convert it to regenerated replenisher.

Therefore, there is a need for a more stable bleach regenerator composition that can be used in a highly concentrated form to provide a regenerated bleach replenisher at lower pH.

[0009]

The above-mentioned problems are as follows: A) An imagewise exposed and color-developed reversal color silver halide photographic element is prepared in a bleaching tank with ferric ethylenediaminetetraacetic acid as a bleaching agent. Bleaching with a bleaching composition comprising a complex, B) supplying a bleaching replenisher to a bleaching tank to overflow the spent bleaching composition from the bleaching tank, C) at least 50% of the overflowing solution Mixing with the bleach regenerator composition of 1. at a volume ratio of at least 1: 1 to obtain a regenerated bleach replenisher, D) the pH of the regenerated bleach replenisher produced in step C.
~ 5.6, and E) the bleaching composition of step A in a bleaching tank was prepared in step D and pH adjusted to 215 mL / m of regenerated bleach replenisher.
Overcome using a processing method comprising replenishing using a bleach replenishment rate of ² or less.

The present invention also has a total bromide ion concentration of at least 210 g / L and a complex of ferric ion with ethylenediaminetetraacetic acid having a pH of 6.0 to 6.5 and a second A bleach regenerator composition is provided in which iron ions are present in an amount of at least 50 g / L.

Further, the pH adjusted regenerated bleach replenisher composition comprises a ferric complex of ethylenediaminetetraacetic acid,
A regenerated bleach replenisher composition having a pH of 5.4 to 5.6 comprises an overflow from a ferric ethylenediaminetetraacetic acid bleaching solution and at least 1: 1 with the pH adjusted bleach regenerator composition described above. Mix at a volume ratio of 1 to produce a regenerated bleach replenisher, then adjust the pH of the regenerated bleach replenisher to 5.4-
It is obtained by adjusting to 5.6.

The present invention effectively provides bleach regenerator compositions and bleach replenishers for processing reversal color silver halide photographic materials. This bleach regenerator composition is more stable and remains in solution at lower pH for extended periods of time. The composition is highly concentrated, for example, in ferric ion concentration, so that higher amounts of bleach overflow can be used to form the bleach replenisher.

These advantages are due to the rather low pH, ie 6.
Obtained by using a bleach regenerant from 0 to 6.5, thus improving stability. However, in order to maximize the concentration of the ingredients, the bromide salt and hydrobromic acid levels were re-blended and adjusted to give improved compositions.

[0014]

A wide variety of different reversal color photographic elements can be used in the practice of this invention. A detailed description of such materials can be found, for example, in Research Disclosure, publication (publicat
on) 36544, 501-541 (September 1994) (hereinafter,
This document is called "Research Disclosure").
Such elements are shown in more detail below.

The reversal color photographic elements used in the practice of this invention typically consist of a support having on one side thereof a plurality of light sensitive silver halide emulsion layers. This photosensitive layer contains
Any of the common silver halides may be included as the photosensitive material.

As explained above, the known color reversal processes of the prior art use a first development, reversal bath, color development, conditioning solution, bleaching bath, fixing bath and stabilizer bath. Also, the stabilizer bath can be replaced with a typical wash or rinse and a "pre-bleach" or "conditioner" is used to stabilize the color image after color development and before bleaching.

An essential component of the bleaching bath is a bleaching agent for converting metallic silver into silver ions. One or more,
Ammonium or alkali metal salts of ferric ethylenediaminetetraacetic acid complexes are useful as bleaching agents in the present invention.

A wide variety of different color reversal processes are well known in the art. For example, one color developing step can be used when a coupling agent is included in the photographic element or three separate color developing steps can be used where the coupling agent is included in the developer. can do. The reversal step can be carried out by using a reversal bath, by a re-exposure step or by incorporating a fog agent in the color developing bath. Bleaching and fixing can be combined in a single step (known as the bleach-fixing step) to provide shorter processing times.

Stabilizing solutions for use in the reversal photographic processing method are also known in the art. Such solutions typically contain formaldehyde or an equivalent material to stabilize the magenta dye image. Further details of such solutions can be found in, for example, US Pat.
No. 786,583.

Alternatively and preferably, it is stabilized by using a pre-bleaching or conditioning solution after color development and before bleaching. Various details of such solutions and their use are described, for example, in US Pat. No. 4,921,779, US Pat. No. 4,975,35.
6, U.S. Pat. No. 5,037,725 and U.S. Pat. No. 5,334,493. Another optional feature of useful conditioning solutions is secondary amines.

The bleaching composition used in the present invention comprises a complex of ferric ion and ethylenediaminetetraacetic acid in a suitable concentration. The amount of iron (III) is generally 50-58
g / L. If desired, salts of one or more complexes can be used. The bleaching composition is fed to the bleaching tank at a suitable rate such that the used bleaching solution overflows from the bleaching tank. Generally, the feed rate is less than or equal to 215 mL / m ² , preferably 1
40 to 215 mL / m ² .

At least 50%, preferably 5% of the bleaching composition overflow to obtain a regenerated bleach replenisher.
0-80%, more preferably 50-75% is mixed with the bleach regenerator composition. This mixing is done with at least a 1: 1 volume ratio and up to a 9: 1 volume ratio of the bleaching composition overflow to bleach regenerator composition. Preferably, the mixing volume ratio is 1: 1 to 3: 1.

After mixing, the pH of the regenerated bleach replenisher was adjusted to
Adjusting down to 5.4-5.6 by adding the appropriate amount of 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 add can be readily determined by routine experimentation, depending on the pH of the regenerated bleach replenisher and the particular acid used. For acetic acid, the amount added is generally 10-20 mL / L. One advantage of the present invention is that
It is necessary to add less acid to this regenerated bleach replenisher than would be added to a conventional regenerant solution.

Then, the pH-adjusted regenerated bleach replenisher was used as "bleach replenisher" at a concentration lower than 215 mL / m ² or
Or equal, preferably at 140-215 mL / m ² bleach replenisher rate added to the bleach tank.

The bleach regenerator composition used in the method of the present invention has a pH of 6.0 to 6.5 (preferably 6.0 to 6.2).
Having. It contains a 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, preferably in an amount of 50 to 58 g / L. Ferric ions for the complex,
Supplied 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.

Also, in the bleach regenerator composition, the source of one or more bromide ions is such that the total bromide ions are at least 210 g / L, preferably 215 to 240 g / L,
Most preferably it is included to be present in an amount of 220-240 g / L. Preferably, the total bromide ion is provided by a combination of hydrobromic acid and a bromide salt (eg sodium bromide, potassium bromide, ammonium bromide or lithium bromide). More preferably at least 80% of the total bromide ions, more preferably 80-97.
% Is given from the bromide salt and the rest is given from hydrobromic acid. Most preferred is ammonium bromide.

One or more corrosion inhibitors may optionally be included in the bleach regenerator composition in suitable concentrations. Preferably, such corrosion inhibitors include, but are not limited to, potassium salts of nitric acid, silicic acid, chromic acid and phosphoric acid. Hexamethylenetetramine and benzotriazole can also be used. Potassium nitrate is preferred.

The preferred embodiment of the present invention is 6.0-6.2.
A) provided by a combination of hydrobromic acid and a bromide salt, the amount from the bromide salt being 80-97 of the total bromide ion.
%, Total bromide ion concentration of 220-240 g / L, b) ferric ion present in an amount of 50-58 g / L and a complex of ethylenediaminetetraacetic acid, and c) from a corrosion inhibitor It is a bleach regenerator composition.

The photographic elements processed in the practice of this invention can be single layer or multilayer color elements. Magnetic backings as well as common supports can be used.
Greater detail on the structure and composition of the elements and suitable processing methods for the various types of elements are set forth in Research Disclosure, supra. All types of emulsions can be used in this element, including but not limited to thin tabular grain emulsions and positive or negative working emulsions.

The present invention is particularly useful for processing imagewise exposed and developed photographic elements containing an arylpyrazolone type magenta dye forming color coupler. Such color couplers are well known in the art, eg, US Pat. No. 5,037,725. The bleaching step described above is generally carried out for 4 to 8 minutes, although longer times can be used if desired. Preferably,
Bleaching time is 6 minutes. The temperature for bleaching is generally
It is higher than room temperature, for example, 30 to 40 ° C.

The process according to the invention can be carried out using a conventional deep tank holding the process solution. This can also be done using what is known in the art as a "low volume thin tank" processing system with a vertical rack or tank or horizontal automatic tray design. Such a processing method and apparatus include, for example,
It is described in US Pat. No. 5,436,118 and the publications cited therein.

[0032]

EXAMPLES The present invention will be further described with reference to the following examples, but it goes without saying that the scope of the present invention is not limited to these examples. All percentages are by volume unless otherwise indicated.

Example 1: Preferred Bleach Regenerator Composition The following ingredients are commercially available: 1.56 molar ammonium ferric ethylenediaminetetraacetate (788 g), hydrobromic acid (61.5 g), ammonium bromide ( 243.9
g) and potassium nitrate (67 g) in water (added to make a total of 1 liter),
A preferred bleach regenerator composition of the present invention was prepared. Final pH
Was 6.0 to 6.2.

Example 2: Preferred Regenerated Bleach Replenisher Composition
And the bleach regenerator composition of Comparative Example 1 with a 1.56 molar concentration of ferric ethylenediaminetetraacetate ammonium bleach (227 g
/ L), bromide ion from various salts (73.8 g /
L) and potassium nitrate (25 g / L) mixed with a conventional color reversal bleaching composition overflow used in the process. The volume ratio of bleaching composition (comparable to bleaching overflow) to bleach regenerator composition was 1: 1.
The resulting regenerated bleach replenisher had a pH of 5.95-6.1. Then the pH was adjusted downward to 5.4-5.6 by adding acetic acid (18 mL / L),
A pH adjusted regenerated bleach replenisher was obtained which could be added directly to the bleaching bath for processing reversal color silver halide photographic materials.

As stated above, the amount of acetic acid required to adjust the pH of the regenerated bleach replenisher was only 18 mL / L. However, the commercial Tetenal Bleachbath E6 / E6
When AR BL-RCY regenerant solution was used in a similar manner,
It was necessary to add acetic acid at 30 mL / L to obtain the desired pH. Obviously, the invention thus makes it possible to reduce the amount of acid used in the preparation of the bleach replenisher, which reduction leads to the advantages mentioned above.

Example 3 Processing of Reverse Color Photographic Elements Regenerated bleach replenisher compositions of this invention were evaluated in another manner of conventional reverse color photographic processing. The present invention was used to process a sample of a typical color reversal photographic film (obtained from Eastman Kodak Company) using the following processing protocol. The film contained a common 1-aryl-5-pyrazolone magenta color coupler in one of the emulsion layers.

Processing protocol: 6 minutes First development ^* 2 minutes Washing with water 2 minutes Inversion bath ^** 6 minutes Color development ^*** 2 minutes Pre-bleaching ^@ 6 minutes Bleaching ^**** 4 minutes Fixing ^# 4 minutes Washing 30 seconds Final Washing ^## 20 minutes Drying ^* General process E-6 Kodak ^TM 1st developer is used. ^{** Using the} generic Process E-6 Kodak ^TM Inversion Bath. ^*** General Process E-6 Uses Kodak ^™ Color Developer. ^@General Process E-6 with Kodak ^™ Prebleach and Replenisher. ^{**** Uses} General Process E-6 Kodak ^™ Bleach (Ferric-EDTA Bleach). ^# Using the general process E-6 Kodak ^TM fixing agent. ^## General Process E-6 Use Kodak ^™ Final Rinse.

At least 50% of bleach bath overflow
Was carried out and the method of the present invention was carried out by mixing it (in a 1: 1 volume ratio) with the bleach regenerator composition of Example 1. This mixing was done in another vessel for 3 minutes at 20-25 ° C. The pH of this mixture, from 5.9 to 6.1, was then adjusted downward by adding acetic acid as described in Example 2, then the adjusted mixture was added to the bleaching bath as a replenisher for processing. . This method was performed on at least 4 bleach tank turns or at least 330 m ² of processed reversal color photographic film. The treatment results were very acceptable. Thus, by using the regenerated bleaching composition described above, a very acceptable processing of the film was obtained.

Examples 4-6: Effect of pH in Bleach Regenerator Compositions Experiments were conducted to demonstrate the critical importance of bleach regenerator compositions having a pH of 6.0-6.5. Several regenerant compositions similar to those described in Example 1 above were subjected to a storage test to see if crystallization or precipitation had occurred. The various compositions had the same ingredients as in Example 1 and various pH values as shown in Table I below.

The results of the storage test are shown in Table I for various compositions. Column 1 describes the storage temperature (-18 to + 21 ° C) at which the composition was stored for 14 days. In the second column,
It indicates when the crystallization result was observed (at room temperature) after removing the composition from the storage environment, ie the "observation time after removal". Samples of each composition were then observed immediately (“0” hours), 24 hours and 11 days after they were removed from the storage environment. Crystals of ferric ethylenediaminetetraacetic acid ammonium complex are measured by visual inspection,
It was identified by Fourier transform infrared (FTIR) spectroscopy.

[0041]

[Table 1]

The results show that the best time and temperature stability for this composition is obtained when the pH is at least 6.0. Control C is stable at pH above 6.5, but at such high pH it was regenerated bleached to reduce the pH to an acceptable level before adding it to the bleaching bath as a replenisher. It has been found to be undesirable because unacceptably large amounts of acid must be added to the replenisher.

In addition, some bleaching compositions were subjected to high temperatures (49
It was stored for 12 days. Examples 4 and 6 were compared to three "control" bleaching compositions outside the scope of the invention, including Control C identified above. Control D is a commercial process E- containing ferric ethylenediaminetetraacetic acid and having a pH of 5.4.
6 (reversal) bleach replenisher. Control E is a commercially available highly concentrated (1.56 mol / L) ferric ammonium ethylenediaminetetraacetate having a pH of 7.0, Kodak (K
ODAK) BL-1.

The results of the amount of ferrous ion formed (g / L) after storage are shown in Table II below. It was observed that the pH decreased for all compositions during the hot storage test, but no precipitation occurred on subsequent freezing of the compositions.

[0045]

[Table 2]

To determine whether changes in pH after storage reduce the bleaching performance of the regenerant composition, Examples 4, 6 and Control C were incorporated into working strength bleach liquors, and then 3 commercially available color reversal films having different species, that is Kodak Ektachrome ^TM (KODAK EKTACHROME ^TM) 400HC film, Kodak Ektachrome ^TM elite ^TM (ELITE ^TM) 1
00 film and Kodak Ektachrome ^™ 64 Pro film were used to bleach. PH stored at room temperature
The solution made from the 6.5 concentrate is called "standard"
Used as a solution. All compositions were brought to the same total iron level and then blown with air to oxidize all ferrous ions to ferric ions. When this was over, the compositions were all pH adjusted to a standard bleaching pH of 5.8.

Table III below lists the "bleach clear time" for each regenerant composition tested. "Bleach clear time" refers to the time when all metallic silver was converted to silver halide for subsequent dissolution and removal in the next fixing step.
The results show that a regenerant composition pH of 6.0-6.5 is desirable for improved composition storage.

[0048]

[Table 3]

Example 7: Bromide Level in Bleach Regenerator Composition
It was also influence bleach regenerator experiments to show the effect of bromide ion concentration in the composition of the present invention. 2 ⁴ factorial experiment in Optimization "target", was carried out about the chemical composition of conventional processes E-6 Bleach. One of those components is bromide ion. The level of bromide ion was varied while bleaching "clear time" (all silver metal halogenated) while maintaining all other ingredients at optimal levels for processing two different commercial color reversal photographic films. The number of seconds to convert to silver) was determined. The optimized or "target" level for bromide ion in this bleach is 73.4 g / L.
Was thought to be. The results obtained are shown in Table IV below.

[0050]

[Table 4]

As can be seen from these data, the average reduction in "clear time" during bleaching for processing the two films by changing the bromide ion level was 44 seconds. This was surprising to the inventors. Previously, the bromide ion in a typical replenisher was relatively high (145-150 g / L), so the amount of bromide ion "used" during bleaching was the rate of bleaching (so bleaching "clearing time". It was thought that it would not have a strong effect on These experiments proved otherwise and showed a significant potential magnitude of a strong effect from increased bromide ion concentration.

[0052]

The present inventors have found that the reuse or regeneration of the bleaching solution (wherein the bromide ions are repeatedly "exhausted") and the tank concentration is below the level found in common replenishers. Additional bromide must be added to compensate for the reduction in bleaching rate (and thus the extension of bleaching "clear time") due to use and additional build up of carryover products. I found that it would not happen.

The bleach replenisher provides tank bleach with three advantages: 1) Dilution of chemicals carried into the chemical reaction and unwanted chemicals produced by the chemical reaction, 2) Chemicals such as bromide ions to make up for use in the chemical reaction needed for bleaching. And 3) Make up for chemicals that are diluted by being carried over or carried into the next solution (ie, fixer).

The conventional Tetenal Process E-6 bleach regenerator has a bromide ion level which takes into account only the first and third advantages mentioned above. We have found that this is inadequate and that the level of bromide ion in the bleach regenerator also treats elements containing bromide ion (4.3 to 5.4 g silver / m ²⁾ that are exhausted in the bleaching reaction. When about 14-18g /
It was found that replenisher L) had to be adjusted. As such, the inventors have determined that it is necessary to increase the level of bromide ion in the regenerant composition used to provide the regenerated bleach replenisher.
The present invention reflects this fact.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Michael John Hate New York, USA 14617, Rochester, Old North Hill 32

Claims (3)

[Claims] 1. A total bromide ion concentration of at least 210 g / L and a complex of ferric ion and ethylenediaminetetraacetic acid having a pH of 6.0 to 6.5, wherein the ferric ion is at least A bleach regenerator composition present in an amount of 50 g / L. 2. Overflow from ferric-ethylenediaminetetraacetic acid bleaching solution is mixed with the bleach regenerant composition of claim 1 in at least a 1: 1 volume ratio to produce a regenerated bleach replenisher. Then the pH of the regenerated bleach replenisher
PH-regulated regenerated bleach replenisher composition obtained by adjusting pH to 5.4 to 5.6. 3. A) bleaching an imagewise exposed, reversal colored silver halide photographic element which has developed a color development phenomenon in a bleaching tank with a bleaching composition containing a complex of ferric ethylenediaminetetraacetic acid, B) bleaching. Supplying replenisher to a bleaching tank to overflow used bleaching composition from the bleaching tank; C) at least 50% of the overflow liquor;
Mixing the bleach regenerant composition described in 1. in a volume ratio of at least 1: 1 to obtain a regenerated bleach replenisher, D) the pH of the regenerated bleach replenisher prepared in step C is 5.4.
~ 5.6, and E) the bleaching composition of step A in a bleaching tank was prepared in step D and pH adjusted to 215 mL / m of regenerated bleach replenisher.
^A method of processing comprising the step of replenishing using a bleach replenishment rate of less than ² .