EP0365955A2 - Developing bath and process for developing a colour-photographic material - Google Patents

Abstract

The invention relates to a colour-photographic developing bath for developing imagewise exposed silver halide materials which contain, on a reflecting film base, at least three light-sensitive silver halide emulsion layers of different spectral sensitivity, which are each spectrally associated with a cyan coupler, magenta coupler and a yellow coupler. The development takes place in the developing baths I and II, the developer content in the developing bath I being greater, when the developing baths are in use, than in the developing bath II and the halide content in the developing bath I being smaller than in the developing bath II. As a result, the development of the yellow layer located at the bottom is promoted, so that a substantially better colour balance is obtained.

Description

For a large part of light-sensitive silver halide recording materials, there are standardized processing processes in which photographic recording materials of any provenance can be processed according to type, for example for the production of colored overlay images from color negative paper using a transparent color negative, the color negative paper containing at least one blue-sensitive, at least one magenta coupler containing a yellow coupler containing green sensitive and at least one cyan coupler containing red sensitive silver halide emulsion layer.

In the worldwide processing process for color negative paper, EP-2 process or Agfacolor process called AP 92, the imagewise exposed color negative paper is subjected to color development, bleaching, fixing, washing and drying where bleaching and fixation can be replaced by bleaching fixation and washing can be replaced by stabilization.

The color development takes 210 seconds. In order to shorten this time, considerable efforts have been made without a new process having found its way into the technology which, using the proven color negative paper, essentially silver bromide emulsions with only low chloride contents (<20 mol% Cl), for Success.

Technically, only a method has recently been used, the development time of which is 45 seconds, which requires a color negative paper which predominantly contains silver chloride emulsions (> 95 mol% Cl) and has a changed developer composition (RA-4 process). Here, the known fact is used that chloride emulsions can be developed faster than bromide emulsions.

When the photographic material is immersed in one of the processing methods described above, the development of the top layer of the color material begins.

The halide released during the reduction of the silver halide, together with the developer solution, penetrates into the underlying emulsion layer and complicates its development. One is particularly disadvantaged three materials containing different spectrally sensitized silver halide emulsion layers, the third, lowest lying emulsion layer. Furthermore, the development of the lowest layer is inhibited by the decrease in the concentration of the developer due to consumption in the upper layers and the increasing length of the diffusion path. When developing color images in which the lowermost emulsion layer produces the yellow partial color image, insufficient development of this layer causes blue shadows to occur. These disadvantages increasingly occur in short processing processes, since the short development time additionally promotes the effect described above. But these phenomena have also been observed when using the usual EP-5 or AP-92 process.

The development bath of this process is regenerated in the course of the continuously carried out processing process in order to replace the developer substance consumed in the development process. The lowest possible regeneration rate is aimed at in order to limit the overflow quantity to a minimum, i.e. The smallest possible amount of liquid is used for regeneration. This requires a high developer concentration in the regenerator, which, however, is not possible due to the low solubility of the CD 3 developer used in this process, so that complete development of the bottom layer is problematic.

In addition, the developer activity is inevitably impaired due to a low regeneration rate due to the resulting high halide content.

In the usual regeneration process, the developer concentration in the use solution is lower than in the regenerator solution, while the halide concentration in the use solution is higher than in the regenerator solution. As a result, the layer with the unfavorable constellation of low color developer content and high halide content is loaded and developed during swelling.

In the case of conventional color paper, this is made more difficult by the fact that the silver bromide or silver bromide chloride emulsions mainly used there release bromide ions during development, which, in contrast to chloride, have a strong development-inhibiting effect.

It was now the object of the invention to provide a processing process in which the disadvantages caused by the inadequate development of the lowest emulsion layer are eliminated and at the same time a low regeneration rate can be used for overflow-free processing.

It has now been found that this problem can be solved by a two-stage development which only requires a regenerator solution.

The invention relates to a color photographic developer bath for the development of imagewise exposed silver halide materials which have at least three light-sensitive silver halide emulsion layers different on a reflective layer support Spectral sensitivity, to which a cyan coupler, a magenta coupler and a yellow coupler are each spectrally assigned, characterized in that the development takes place in the development baths I and II, the developer content in the development bath I being greater than in the development bath I and II when the development baths are in use Halide content in developing bath I is smaller than in developing bath II.

The concentrations of developer substance in developing bath I are preferably in the range from 0.01 to 0.03 mol / l, particularly preferably between 0.014 and 0.023 mol / l; in developing bath II in the range of 0.002 and 0.02 mol / l, particularly preferably between 0.005 and 0.01 mol / l.

The concentration of halide in developing bath I is preferably 0.0015 to 0.015 mol / l, particularly preferably between 0.004 and 0.008 mol / l; in developing bath II in the range of 0.017 mol and 0.04 mol / l, particularly preferably between 0.02 and 0.03 mol / l.

Another object of the invention is a method for developing an exposed color photographic material using developing baths I and II described above, characterized in that the residence time of the color photographic material in developing bath I is less than 50% of the total development time.

The residence time of the color photographic material in developer bath I is preferably 10-20% of the total development time.

This two-stage development achieves an optimal loading of the layer with a high developer concentration with a low halide content. The developer solution containing an optimal activity potential - high developer content with low halide content - is absorbed by the layer in the development stage I during the swelling, specifically in a limited residence time of <50%, preferably 10-20% of the total development time.

The development, still beginning in development stage I, consumes a small amount of developer substance corresponding to the short residence time, so that the favorable ratio of high developer concentration and low halide content in the working solution of the first developer bath is largely retained. The color photographic material conditioned in this way is then finished in the second developer bath.

As a result, the developer concentration in the second bath is substantially lower in the use state and the halide concentration is correspondingly higher than in the first development bath.

As a result, the development within the various emulsion layers takes place in a concentration gradient and the lowest layer keeps the favorable development conditions brought from the development bath I for the longest. Towards the end of the development, the concentration ratios here have also adjusted to the values of the second bath.

Another advantage of the invention is that only one regenerator solution is required, which is fed to bath I. The regenerator feed is expediently based on the principle of level compensation. This ensures that no overflow occurs because the carry-over volume is equal to the feed volume of the regenerator solution.

The transport of the regenerator solution from bath I to bath II takes place through the photo material. For safety reasons, the overflow of bath I is connected to that of bath II.

In addition, when using this method in continuous operation, it can be advantageous to add wetting agents and complexing agents to developer solutions I and II, which accelerate the penetration of the solutions into the emulsion layers or bind calcium ions from the gelatin and the water.

Suitable complexing agents for complexing calcium ions are, for example, aminopolycarboxylic acids, which are well known per se. Typical examples of such aminopolycarboxylic acids are nitrilotriacetic acid, ethylenediaminetetraacetic acid (EDTA), 1,3-diamino-2-hydroxypropyltetraacetic acid, diethylenetriaminepentaacetic acid, N, N'-bis- (2-hydroxybenzyl) -ethylenediamine-N, N'-diesiacetic acid, hydroxyethyldiacetic acid, hydroxyethyldiacetic acid, hydroxyethyldiacetic acid, hydroxyethyldiacetic acid, hydroxyethyldiacetic acid, hydroxyethyldiacetic acid, hydroxyethyldiacetic acid, hydroxyethyldiacetic acid, hydroxyethyldiacetamic acid, hydroxyethylenediaminodiacetate, and aminomalonic acid.

Other calcium complexing agents are polyphosphates, phosphonic acids, aminopolyphosphonic acids and hydrolyzed polymaleic anhydride, e.g. Sodium hexametaphosphate, 1-hydroxyethane-1,1-diphosphonic acid, aminotrismethylenephosphonic acid, ethylenediaminetetramethylenephosphonic acid. 1-hydroxyethane-1,1-diphosphonic acid also acts as an iron complexing agent.

It is also advantageous to add iron complexing agents to the two developer solutions.

Special iron complexing agents are e.g. 4,5-dihydroxy-1,3-benzenedisulfonic acid, 5,6-dihydroxy-1,2,4-benzenetrisulfonic acid and 3,4,5-trihydroxybenzoic acid.

About 0.2 to about 1.8 moles of a calcium complexing agent per mole of developer substance are preferably used for complexing the calcium.

The iron complexing agent is used in amounts of about 0.02 to about 0.2 moles per mole of developer substance.

Particularly suitable primary aromatic amino developer substances are p-phenylenediamines and in particular N, N-dialkyl-p-phenylenediamines, in which the alkyl groups and the aromatic nucleus are substituted or unsubstituted. Examples of such compounds are N, N-diethyl-p-phenylenediamine hydrochloride, 4-N, N-diethyl-2-methylphenylenediamine hydrochloride, 4- (N-ethyl-N-2-methanesulfonylaminoethyl -2-methylphenylenediamine sesquisulfate monohydrate, 4 - (N-Ethyl-N-2-hydroxyethyl) -2-methylphenylenediamine sulfate and 4-N, N-diethyl-2,2'-methanesulfonylaminoethylphenylenediamine hydrochloride.

It may also be expedient to add white toners, white couplers and antioxidants to the solutions. Suitable antioxidants are e.g. Hydroxylamine and diethylhydroxylamine and sulfites, which are preferably used in an amount of up to 5 g / l.

Optical brighteners, lubricants, e.g. Polyalkylene glycols, surfactants, stabilizers, e.g. heterocyclic mercapto compounds or nitrobenzimidazole and means for adjusting the desired pH. The developer solution can contain benzyl alcohol or be free of benzyl alcohol.

The developers according to the invention are, in particular, aqueous alkaline solutions which have a pH above 7, in particular from 9 to 13. In order to set this pH, known buffer substances such as alkali carbonates and alkali phosphates are used.

When in use, the pH in developing bath I is higher than in developing bath II.

When using the two-stage development according to the invention in the EP-2 or AP-92 process (total development time 210 sec.), Color photographic material is developed whose silver halide emulsions generally contain at least 70 mol% bromide.

The silver halide emulsion layers of a color photographic material which the invented according to the two-stage development according to a rapid development according to the RA-4 process with a development period of 45 seconds, at least 80, preferably at least 95 mol% of chloride should be present.

The ready-to-use solutions can be prepared from the individual components or from so-called concentrates, the individual components being dissolved in the concentrates in a much higher concentration. The concentrates are adjusted so that a so-called regenerator can be produced from them, i.e. a solution which has somewhat higher concentrations of the individual components than the ready-to-use solution, on the one hand results in a ready-to-use solution by further dilution and addition of a starter, preferably KCl or KBr, and on the other hand is constantly added to a developer solution in use to prevent the development to replace used chemicals or chemicals carried over from the developer solution by overflow or by the developed material. Halide ions are usually not added, except for the freshly prepared developer, since halide ions are released from the photographic material by the development.

However, if halide is added to the developer regeneration solution from the start or if there is a possibility of contamination with halide by other developer constituents, the halide concentration in the development baths I and II changes accordingly. The halide concentrations given above refer to the use of halide-free developer regeneration solutions.

After development, the photographic material is stopped, bleached, fixed, washed and dried as usual, bleaching and fixing can be combined for bleach-fixing, and the washing can be replaced by a stabilizing bath. If the bleach or bleach-fix bath is sufficiently acidic, the stop bath can also be dispensed with.

example 1

• 1. Eine Substratschicht aus 200 mg Gelatine mit KNO₃- und Chromalaunzusatz.
• 2. Eine Haftschicht aus 320 mg Gelatine.
• 3. Eine blauempfindliche Silberbromidchloridemulsions­schicht (20 mol-% Chlorid) aus 450 mg AgNO₃ mit 1600 mg Gelatine, 1,0 mmol Gelbkuppler, 27,7 mg 2,5-Dioctylhydrochinon und 650 mg Trikresylphosphat.
  Die Emulsion wurde durch Doppeleinlauf mit einer Korngröße von 0,8 µm hergestellt, in der üblichen Weise geflockt, gewaschen und mit Gelatine redis­pergiert. Das Gewichtsverhältnis Gelatine-Silber (als AgNO₃) betrug 0,5. Die Emulsion wurde an­schließend mit 60 µmol Thiosulfat pro mol Ag zur optimalen Empfindlichkeit gereift, für den blauen Spektralbereich mit einer Verbindung der Formel
  
  sensibilisiert und stabilisiert.
• 4. Eine Zwischenschicht aus 1200 mg Gelatine, 80 mg 2,5-Dioctylhydrochinon und 100 mg Trikresylphos­phat.
• 5. Eine grünempfindliche Silberbromidchloridemulsions­schicht (20 mol-% Chlorid) aus 530 mg AgNO₃ mit 750 mg Gelatine sensibilisiert mit der Verbindung der Formel
  
  0,625 mmol Purpurkuppler, 118 mg α-(3-t-Butyl-4-­hydroxyphenoxy)-myristinsäureethylester, 43 mg 2,5-­Dioctylhydrochinon, 343 mg Dibutylphthalat und
  43 mg Trikresylphosphat.
• 6. Eine Zwischenschicht aus 1550 mg Gelatine, 285 mg eines UV-Absorbers der Formel
  
  80 mg Dioctylhydrochinon und 650 mg Trikresylphos­phat.
• 7. Eine rotempfindliche Silberbromidchloridemulsions­schicht (20 mol-% Chlorid) aus 400 mg AgNO₃ mit 1470 mg Gelatine mit den in der nachfolgenden Ta­belle angegebenen Verbindungen sensibilisiert, 0,780 mmol Blaugrünkuppler, 285 mg Dibutylphthalat und 122 mg Trikresylphosphat.
• 8. Eine Schutzschicht aus 1200 mg Gelatine, 134 mg eines UV-Absorbers gemäß 6, Schicht und 240 mg Tri­kresylphosphat.
• 9. Eine Härtungsschicht aus 400 mg Gelatine und 400 mg Härtungsmittel der Formel
  

A layer support made of paper coated on both sides with polyethylene was provided with the following layers. The quantities refer to 1 m².

• 1. A substrate layer of 200 mg of gelatin with KNO₃- and Chromalaunzusatz.
• 2. An adhesive layer made of 320 mg of gelatin.
• 3. A blue-sensitive silver bromide chloride emulsion layer (20 mol% chloride) from 450 mg AgNO₃ with 1600 mg gelatin, 1.0 mmol yellow coupler, 27.7 mg 2,5-dioctylhydroquinone and 650 mg tricresyl phosphate.
  The emulsion was prepared by double inlet with a grain size of 0.8 μm, flocculated in the usual way, washed and redispersed with gelatin. The weight ratio gelatin-silver (as AgNO₃) was 0.5. The emulsion was then ripened with 60 μmol thiosulfate per mol Ag for optimal sensitivity, for the blue spectral range with a compound of the formula
  
  sensitized and stabilized.
• 4. An intermediate layer of 1200 mg gelatin, 80 mg 2,5-dioctylhydroquinone and 100 mg tricresyl phosphate.
• 5. A green-sensitive silver bromide chloride emulsion layer (20 mol% chloride) from 530 mg AgNO₃ with 750 mg gelatin sensitized with the compound of the formula
  
  0.625 mmol of purple coupler, 118 mg of α- (3-t-butyl-4-hydroxyphenoxy) myristic acid ethyl ester, 43 mg of 2,5-dioctylhydroquinone, 343 mg of dibutyl phthalate and
  43 mg tricresyl phosphate.
• 6. An intermediate layer of 1550 mg gelatin, 285 mg of a UV absorber of the formula
  
  80 mg dioctyl hydroquinone and 650 mg tricresyl phosphate.
• 7. A red-sensitive silver bromide chloride emulsion layer (20 mol% chloride) sensitized from 400 mg AgNO₃ with 1470 mg gelatin with the compounds listed in the table below, 0.780 mmol cyan coupler, 285 mg dibutyl phthalate and 122 mg tricresyl phosphate.
• 8. A protective layer of 1200 mg of gelatin, 134 mg of a UV absorber according to 6, layer and 240 mg of tricresyl phosphate.
• 9. A hardening layer of 400 mg gelatin and 400 mg hardening agent of the formula
  

The following connections were used as color couplers:

In the comparative example, a step wedge is exposed onto the color photographic material described above and processed under the usual processing conditions as follows: developer 210 s 38 ° C Bleach-fixer 90 s 38 ° C Watering 210 s 33 ° C dry

Bleichfixierbad-Tanklösung, Gebrauchszustand Wasser 950 ml Natriumdisulfit 8 g Ammoniumthiosulfat 80 g Ammonium-Eisen-Ethylendiamintetraessigsäure 55 g Silber 3 g pH-Wert 6,8 (Korrektur mit Essigsäure) An overflow-free regeneration rate of 60 ml / m² was used for the developer, which gives the state of use.

Bleach-fix tank solution, use condition water 950 ml Sodium disulfite 8 g Ammonium thiosulfate 80 g Ammonium-iron-ethylenediaminetetraacetic acid 55 g silver 3 g pH 6.8 (correction with acetic acid)

The sensitometric data of the processed step wedge with regard to shoulder gradation and maximum densities are listed in Table 1.

Example according to the invention

An exposed step wedge is developed according to the invention in developers I and II.

The state of use was generated with the same regeneration rate / m² and the same developer / regenerator composition as in the comparative example. Processing conditions: Developer I 30 s 27 ° C Developer II 180 s 38 ° C Bleach-fixer 90 s 38 ° C Watering 210 s 33 ° C dry

The bleach-fix bath solution in use has the same composition as in the comparative example.

The sensitometric data of the processed step wedge with regard to shoulder gradation and maximum densities are listed in Table 1. Table 1 Shoulder gradation, relative value Maximum density yellow purple Blue green yellow purple Blue green Comparative example 1.90 3.00 2.90 2.20 2.50 2.42 example according to the invention 3.00 3.20 3.10 2.40 2.55 2.45

The comparison shows that the values of the shoulder gradation and the maximum density of the underlying yellow layer obtained in the comparative example are too low in relation to the purple and cyan values in terms of color balance.

The processing according to the invention favors the development of the yellow layer below, so that the higher values of the shoulder gradation and the maximum density result in a much better color balance.

Example 2

A color photographic recording material was produced by coating on a support on both tig with polyethylene coated paper the following layers were applied in the given order. The quantities indicated relate to 1 m². For the silver halide application, the corresponding amounts of AgNO₃ are given.

Layer structure:

• 1st layer (substrate layer):
  0.2 g gelatin
• 2nd layer (blue-sensitive layer):
  blue-sensitive silver halide emulsion (99.5 mol% chloride, 0.5 mol% bromide, average grain diameter 0.8 µm) from 0.63 g AgNO₃ with
  1.38 g gelatin
  0.95 g yellow coupler Y
  0.2 g white coupler W
  0.29 g tricresyl phosphate (CPM)
• 3rd layer (protective layer)
  1.1 g gelatin
  0.06 g 2,5-dioctylhydroquinone
  0.06 g dibutyl phthalate (DBP)
• 4th layer (green-sensitive layer)
  green-sensitized silver halide emulsion (99.5 mol% chloride, 0.5 mol% bromide, average grain diameter 0.6 µm) from 0.45 g AgNO₃ with 1.08 g gelatin
  0.41 g purple coupler M
  0.16 g of ethyl α- (3-t-butyl-4-hydroxyphenoxy) myristic acid
  0.08 g 2,5-dioctyl hydroquinone
  0.34 g DBP
  0.04 g CPM
• 5th layer (UV protective layer)
  1.15 g gelatin
  0.6 g UV absorber of the formula
  
  0.045 g 2,5-dioctyl hydroquinone
  0.04 g CPM
• 6th layer (red-sensitive layer)
  Red-sensitized silver halide emulsion (99.5 mol% chloride, 0.5 mol% bromide, average grain diameter 0.5 µm) from 0.3 g AgNO₃ with
  0.75 g gelatin
  0.36 g cyan coupler C
  0.36 g CPM
• 7th layer (UV protective layer)
  0.35 g gelatin
  0.15 g UV absorber according to the 5th layer
  0.2 g CPM
• 8th layer (protective layer)
  0.9 g gelatin
  0.3 g of curing agent H of the following formula
  

The couplers used have the following formula:

In the following comparative example, a step wedge is exposed onto the color photographic material described above and processed under the usual processing conditions as follows: developer 45 s 35 ° C Bleach-fixer 45 s 35 ° C Watering 90 s 33 ° C dry

An overflow-free regeneration rate of 60 ml / m² was used for the developer, which gives the state of use. Composition of the baths: developer Tank solution regenerator Condition of use water 960 ml 960 ml Diethylene glycol 30 ml 30 ml Iso-nonyl-phenoxipolyglycidol 0.5 g 0.5 g 4,5-dihydroxy-1,3-benzenedisulfonic acid 0.5 g 0.5 g Ethylenediaminetetraacetic acid 2 g 2 g Potassium sulfite 0.1 g 0.3 g N, N-diethylhydroxyamine, 85% by weight 2 ml 8 ml Sodium chloride 3 g 0.3 g CD3 3 g 10 g Potassium carbonate 20 g 20 g PH value 10.1 11.3

The bleach-fix bath tank solution has the same composition as in Example 1, but with a pH of 5.5 (correction with acetic acid).

The sensitometric data of the processed step wedge with regard to shoulder gradation and maximum densities are listed in Table 2.

Example according to the invention:

An exposed step wedge is developed according to the invention in developers I and II. The state of use was generated with the same regeneration rate / m² and the same developer / regenerator composition as in the comparative example. Processing conditions: Developer I 6 s 27 ° C Developer II 39 s 35 ° C Bleach-fixer 45 s 35 ° C Watering 90 s 33 ° C dry

The bleach-fix bath tank solution has the same composition as in the comparative example.

The sensitometric data of the processed step wedge with regard to shoulder gradation and maximum densities are listed in Table 2. Table 2 Shoulder gradation, relative value Maximum density yellow purple Blue green yellow purple Blue green Comparative example 2.25 2.70 2.80 1.85 2.50 2.60 example according to the invention 2.90 2.80 2.90 2.35 2.55 2.60

The comparison shows that the values of the shoulder gradation and the maximum density of the underlying yellow layer obtained in the comparative example are too low in relation to the purple and cyan values in terms of color balance. The processing in the example according to the invention favors the development of the yellow layer below, so that the higher values of the shoulder gradation and the maximum density result in a much better color balance.

Claims (9)

1. Color photographic developer tape for the development of imagewise exposed silver halide materials which contain at least three light-sensitive silver halide emulsion layers of different spectral sensitivity on a reflective layer support, to which a cyan coupler, a magenta coupler and a yellow coupler are each spectrally assigned, characterized in that the development in the developing baths I and II takes place, the developer content in developer bath I being greater than in developer bath II and the halide content in developer bath I being smaller than in developer bath II when the developer baths are in use. 2. Photographic developer bath according to claim 1, characterized in that the concentrations of developer substance in developing bath I are in the range from 0.01 to 0.03 mol / l and in developing bath II in the range from 0.002 to 0.02 mol / l. 3. Photographic developer bath according to claim 1, characterized in that the concentrations of developer substance in developing bath I are in the range from 0.014 to 0.023 mol / l and in developing bath II in the range from 0.005 to 0.01 mol / l. 4. Photographic developer bath according to claim 1, characterized in that the concentrations of halide in developing bath I are in the range from 0.0015 to 0.015 mol / l and in developing bath II in the range from 0.017 to 0.04 mol / l. 5. Photographic developer bath according to claim 1, characterized in that the concentrations of halide in the developing bath I in the range from 0.004 to 0.008 mol / l and in the developing bath II in the range from 0.02 to 0.03 mol / l. 6. A method for developing an exposed color photographic material using two developing baths I and II according to claim 1, characterized in that the residence time of the color photographic material in bath I is less than 50% of the total development time. 7. The method according to claim 6, characterized in that the residence time of the color photographic material in bath I is in the range of 10-20% of the total development time. 8. A method for developing an exposed color photographic material using two developing baths I and II according to claim 1, characterized in that the pH in the developing baths I and II in the state of use is between 9 and 13. 9. A method for developing an exposed color photographic material using two developing baths I and II according to claim 1, characterized in that in the use state, the pH of the developing bath I is higher than the pH of the developing bath II.