EP0370348A1 - Photographic-reversal method - Google Patents

Abstract

A reverse photographic process for producing positive photographic images by imagewise exposure of the light-sensitive material containing at least one silver halide emulsion layer, black and white initial development of the material, chemical fogging, color development, bleaching, fixing, washing or stabilizing and drying, in which the material from the first development is converted to color development without any intermediate steps such as intermediate washing or diffuse second exposure, the first development bath contains only one or more N, N-dialkyl-p-phenylenediamine derivatives as developer and a tin (II) complex compound and is adjusted to a pH <8 , and the color development bath also contains only one or more N, N-dialkyl-p-phenylenediamine derivatives as developer and is adjusted to a pH> 10, requires significantly less time than the conventional method, but provides equivalent Erg results.

Description

The invention relates to a method for processing photographic reversal materials, which is of considerably shorter duration than conventional methods.

In the photographic reversal process, a positive colored image is formed using a color slide by exposing a negative working color reversal paper through a special reversal development. The color reversal paper has at least one blue-sensitive silver-sensitive layer containing a yellow coupler, at least one green-sensitive layer containing green-sensitive and at least one red-sensitive silver halide layer containing a cyan coupler.

The usual reverse processing using the chromogenic color process is divided into at least six steps:
- First development = black and white negative development. The silver halide, which was exposed imagewise during the exposure, is developed by a first developer into a black and white negative. Metol-hydroquinone or phenidone-hydroquinone developers are generally used.
- Intermediate washing = removal of the first developer to avoid post-development in the color development bath.
- Diffuse second exposure or chemical fogging Everything silver halide not developed in the first developer is made developable.
- Color development = development of the silver halide activated by the second exposure or chemical fogging into silver and dye formation.

Proportional to the silver halide reduced in the color developer, the dyes are formed in a corresponding amount from the color coupler and the developer oxidation product formed.
- Bleaching and fixing or bleach-fixing = removing all of the silver formed in the initial and color development, so that a positive dye image remains.
- Final washing or stabilizing bath = washing out chemicals and stabilizing image dyes and image surface.

This reversal process could be made considerably easier, faster and more efficient if one could do without the watering between the first and color development and the diffuse second development or chemical veiling in a separate step. If the process was carried out conventionally without the need for watering, however, dragging the first developer into the color developer in conjunction with the diffuse second exposure would result in black and white post-development, which would severely impair the quality of the finished color image.

Postponement of the first developer would, however, be of minor importance if it were comparable to the structure of the color developer and would not cause any side reactions in the color development bath.

If a color developer were used in the first and color development baths, dragging the developer away without intermediate washing would be no disadvantage, but this developer in the first development bath would have to be suitable for black-and-white development (reduction of the exposed silver halide nuclei to image silver) and a coupling of the developing developer oxidation product with the color couplers in the photographic material should not take place.

DE-A-2 249 857 describes a process for reverse development in which both a black-and-white developer and a color developer who is disabled in his color coupling activities are used in the first development bath is set. In a second bath, the coupling-inhibiting effects caused, for example, by sulfite, ascorbic acid, etc., are eliminated and the color coupling can take place. However, the disadvantage of this process is the simultaneous presence of two types of developer and the resulting coordination and process problems. Overall, only a moderate image quality is achieved.

The object of the invention was now to develop a reversal development method in which washing between the first and color development baths and diffuse second exposure can be dispensed with without the disadvantages mentioned above occurring.

The present invention relates to a photographic reversal process for producing positive photographic images by imagewise exposure of the light-sensitive material containing at least one silver halide emulsion layer, initial black and white development of the material, chemical fogging, color development, bleaching, fixing, washing or stabilizing and drying, in which the material is transferred from the first development to the color development without any intermediate steps such as intermediate washing or diffuse second exposure, the first development bath contains only one or more N, N-dialkyl-p-phenylenediamine derivatives as developers and at least one tin (II) complex compound and to a pH Value is set to <8, and the color development bath likewise exclusively contains one or more N, N-dialkyl-p-phenylenediamine derivatives as developer and is set to a pH value> 10.

worin
R₁, R₂ H, gegebenenfalls substituiertes C₁-C₄-Alkyl, C₆-C₁₀-Aryl und C₁-C₃-Alkoxy,
R₃ H, gegebenenfalls substituiertes C₁-C₄-Alkyl, C₆-C₁₀-Aryl und C₁-C₃-Alkoxy, Halogen,
n 1 oder 2 bedeuten.Suitable developer substances of the p-phenylenediamine type correspond to the general formula

wherein
R₁, R₂ H, optionally substituted C₁-C₄ alkyl, C₆-C₁₀ aryl and C₁-C₃ alkoxy,
R₃ H, optionally substituted C₁-C₄-alkyl, C₆-C₁₀-aryl and C₁-C₃-alkoxy, halogen,
n is 1 or 2.

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.

The concentrations of the developer substances in the first development bath are in the range from 2 to 20 g / l, preferably 4 to 10 g / l.

In a preferred embodiment, no developer substances are added to the second development bath, so that only the portions introduced from the first development bath are contained.

The first development bath preferably contains at least one substance which prevents the color coupler from reacting with the developer oxidation product.

Suitable compounds are e.g. Citracic acid, sulfite, hydroxylamine and derivatives, ascorbic acid and derivatives and colorless couplers that lead to colorless coupling products (white couplers). They are preferably used in an amount of 0.005 to 0.1 mol / l.

The concentration of the tin (II) complex compounds in the first development bath is 0.001 to 0.05 mol / l.

As complexing agents for the Sn (II) complex compounds, carboxylic acids and phosphonic acids are particularly suitable, such as. B .:

worin
R₄, R₅, R₆, R₇ gleich oder verschieden sind und Wasser­stoff, Alkyl mit 1 bis 4 C-Atomen, Hydroxyl oder (CH₂)_mX bedeuten, wobei X eine Phosphono- oder eine Carboxygruppe sein kann und m 0 oder eine ganze Zahl von 1 bis 4 ist, mit der Maßgabe, daß wenig­stens einer der Substituenten R₄ bis R₇ aus einer Phosphonogruppe besteht oder eine solche enthält.Aminocarboxylic acids, such as. B. ethylenediaminetetraacetic acid and those mentioned in German Offenlegungsschrift 1 814 834; Hydroxy carboxylic acids such as gluconic acid and citric acid; Polycarboxylic acids such as oxalic acid; Phosphonic acids of the type of nitrilomethylenephosphonic acids and alkylidenephosphonic acids, as described, for example, in the German patent application 2,009,693 are listed, azacycloalkane-2,2-diphosphonic acids as known from German Offenlegungsschrift 2,610,678 or phosphonocarboxylic acids with at least one carboxy and at least one phosphono group in the molecule, in particular acids of the following general formula:

wherein
R₄, R₅, R₆, R₇ are the same or different and are hydrogen, alkyl having 1 to 4 carbon atoms, hydroxyl or (CH₂) _m X, where X can be a phosphono or a carboxy group and m 0 or an integer of 1 to 4, with the proviso that at least one of the substituents R₄ to R₇ consists of or contains a phosphono group.

A particularly suitable phosphonocarboxylic acid is 1,2,4-tricarboxybutane-2-phosphonic acid. The complexing agents mentioned can be used in the baths to be used according to the invention individually or in combination and, if appropriate, in excess, based on the tin-II ions present.

In a further preferred embodiment, the first developer contains a phosphate or acetate buffer and is adjusted to a pH <7. In this case, compounds which are intended to prevent a reaction of the developer oxidation product with the color coupler can be dispensed with.

In addition, when using this method in continuous operation, it may be advantageous to add wetting agents and complexing agents to the two developer solutions, 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 (HEDP), 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, for example, 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.

It may also be expedient to add white toners and / or white couplers to the solutions.

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 may also contain less than 5 g / l benzyl alcohol; it is preferably free of benzyl alcohol.

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 and on the other hand always gives one developer solution in use is added to replace the chemicals consumed during development or chemicals carried over from the developer solution by overflow or by the developed material.

After development, the photographic material is 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.

Color reversal photographic paper is particularly suitable as color reversal material, which is in particular a paper laminated with a barite layer or preferably an α-olefin polymer layer (e.g. polyethylene) onto which the light-sensitive layers are applied.

The material usually contains at least one red-sensitive, green-sensitive and blue-sensitive silver halide emulsion layer as well as, if necessary, intermediate layers and protective layers.

Binding agents, silver halide grains and color couplers are essential components of the photographic emulsion layers.

Gelatin is preferably used as the binder. However, this can be replaced in whole or in part by other synthetic, semi-synthetic or naturally occurring polymers. Synthetic gelatin substitutes are, for example, polyvinyl alcohol, poly-N-vinylpyrrolidone, polyacrylamides, polyacrylic acid and their derivatives, in particular their copolymers. Naturally occurring gelatin substitutes are, for example, other proteins such as albumin or casein, Cellulose, sugar, starch or alginates. Semi-synthetic gelatin substitutes are usually modified natural products. Cellulose derivatives such as hydroxyalkyl cellulose, carboxymethyl cellulose and phthalyl cellulose as well as gelatin derivatives which have been obtained by reaction with alkylating or acylating agents or by grafting on polymerizable monomers are examples of this.

The binders should have a sufficient amount of functional groups so that enough resistant layers can be produced by reaction with suitable hardening agents. Such functional groups are in particular amino groups, but also carboxyl groups, hydroxyl groups and active methylene groups.

The gelatin which is preferably used can be obtained by acidic or alkaline digestion. Oxidized gelatin can also be used. The preparation of such gelatins is described, for example, in The Science and Technology of Gelatine, edited by AG Ward and A. Courts, Academic Press 1977, page 295 ff. The gelatin used in each case should contain the lowest possible level of photographically active impurities (inert gelatin). High viscosity, low swelling gelatins are particularly advantageous.

The silver halide present as a light-sensitive component in the photographic material can contain chloride, bromide or iodide or mixtures thereof as the halide. For example, the halide content of at least one layer can consist of 0 to 15 mol% of iodide, 0 to 100 mol% of chloride and 0 to 100 mol% of bromide. Silver bromide chloride emulsions with on the one hand at least 80 mol% bromide and 0 to 20 mol% chloride and on the other hand with at least 95 mol% chloride and 0 to 5 mol% bromide are preferred. It can be predominantly compact crystals, e.g. are regular cubic or octahedral or can have transitional forms. However, platelet-shaped crystals can preferably also be present, the average ratio of diameter to thickness of which is preferably at least 5: 1, the diameter of a grain being defined as the diameter of a circle with a circle content corresponding to the projected area of the grain. However, the layers can also have tabular silver halide crystals in which the ratio of diameter to thickness is substantially greater than 5: 1, e.g. 12: 1 to 30: 1.

The silver halide grains can also have a multi-layered grain structure, in the simplest case with an inner and an outer grain area (core / shell), the halide composition and / or other modifications, such as doping of the individual grain areas, being different. The average grain size of the emulsions is preferably between 0.2 .mu.m and 2.0 .mu.m, the grain size distribution can both be homo- and heterodisperse. Homodisperse grain size distribution means that 95% of the grains do not deviate from the mean grain size by more than ± 30%. In addition to the silver halide, the emulsions can also contain organic silver salts, for example silver benzotriazolate or silver behenate.

Two or more kinds of silver halide emulsions, which are prepared separately, can be used as a mixture.

The photographic emulsions can be spectrally sensitized using methine dyes or other dyes. Particularly suitable dyes are cyanine dyes, merocyanine dyes and complex merocyanine dyes.

Research Disclosure 17643/1978 in Department IV contains an overview of the polymethine dyes suitable as spectral sensitizers, their suitable combinations and combinations with a super-sensitizing effect.

The following dyes, sorted by spectral range, are particularly suitable:

1. as red sensitizers

9-ethylcarbocyanines with benzthiazole, benzselenazole or naphthothiazole as basic end groups which are in the 5- and / or 6-position by halogen, methyl, Methoxy, carbalkoxy, aryl may be substituted and 9-ethyl-naphthoxathia or -selenecarbocyanine and 9-ethyl-naphthothiaoxa- or -benzimidazocarbocyanine, provided that the dyes carry at least one sulfoalkyl group on the heterocyclic nitrogen.

2. as green sensitizers

9-ethyl carbocyanines with benzoxazole, naphthoxazole or a benzoxazole and a benzthiazole as basic end groups, and also benzimidazocarbocyanines, which may also be further substituted and must likewise contain at least one sulfoalkyl group on the heterocyclic nitrogen.

3. as blue sensitizers

symmetrical or asymmetrical benzimidazo-, oxa-, thia- or selenacyanines with at least one sulfoalkyl group on the heterocyclic nitrogen and optionally further substituents on the aromatic nucleus, and apomerocyanines with a rhodanine group.

Sensitizers can be dispensed with if the intrinsic sensitivity of the silver halide is sufficient for a certain spectral range, for example the blue sensitivity of silver bromides.

The differently sensitized emulsion layers are assigned non-diffusing monomeric or polymeric color couplers, which can be located in the same layer or in a layer adjacent to it. Usually cyan couplers are assigned to the red-sensitive layers, purple couplers to the green-sensitive layers and yellow couplers to the blue-sensitive layers.

Color couplers for producing the blue-green partial color image are usually couplers of the phenol or α-naphthol type.

Color couplers for producing the purple partial color image are generally couplers of the 5-pyrazolone, indazolone or pyrazoloazole type.

Color couplers for producing the yellow partial color image are generally couplers with an open-chain ketomethylene group, in particular couplers of the α-acylacetamide type; Suitable examples are α-benzoylacetanilide couplers and α-pivaloylacetanilide couplers.

example

A color photographic recording material which is suitable for the processing method according to the invention was produced by applying the following layers in the order given to a layer support on paper coated on both sides with polyethylene. The quantities given 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
0.08 g 2,5-dioctyl hydroquinone
0.5 g DBP
0.04 g CPM

5th layer (UV protective layer)

0,045g 2,5-Dioctylhydrochinon
0,04 g TKP1.15 g gelatin
0.6 g UV absorber of the formula

0.045g 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 of the following formula

The components used have the following formula:

A step wedge is exposed on the photographic material described above and processed as follows:
First developer 45 sec, 30 ° C
Color developer 45 sec, 30 ° C
Bleach-fix 45 sec, 30 ° C
Soak (3 x 15 sec) 45 sec, 30 ° C
dry

The individual processing baths had the following composition: First developer water 800 ml 4- (N-ethyl-N-2-hydroxyethyl) -2-methylphenylenediamine sulfate monohydrate (CD 4) 7 g Sn (II) phosphonobutane tricarboxylic acid 3.2 g Sodium sulfite 0.6 g Citracin acid 5 g Potassium carbonate 20 g pH adjustment to 7.5, then fill up to 1 liter with water. Second developer water 900 ml EDTA 2 g HEDP, 60% by weight 0.5 ml Sodium chloride 1 g N, N-diethylhydroxylamine, 85% by weight 5 ml 4- (N-ethyl-N-2-methanesulfonylaminoethyl) -2-methylphenylenediamine sesquisulfate monohydrate (CD 3), 50% by weight 8 ml Potassium carbonate 25 g pH adjustment to pH 11 with KOH or H₂SO₄; Make up to 1 liter with water. Bleach-fix bath: water 800 ml EDTA 4 g Ammonium thiosulfate 100 g Sodium sulfite 15 g Ammonium iron EDTA complex 60 g 3-mercapto-1,2,4-triazole 2 g pH adjustment to pH 7.3 with ammonia or acetic acid; Make up to 1 liter with water.

Comparative example

• 1. der Erstentwickler ohne Zinnkomplex eingesetzt,
• 2. nach dem Erstentwickler 60 sek. gewässert,
• 3. eine Zweitbelichtung durchgeführt und anschließend wie in Beispiel 1 weiter verarbeitet.

The procedure is as in Example 1, however

• 1. the first developer used without a tin complex,
• 2. after the first developer 60 sec. watered,
• 3. a second exposure is carried out and then further processed as in Example 1.

Both methods lead to practically the same sensitometric results with regard to gradation, neutrality of the adjustment, maximum densities, whites and purity of the colors.

According to the invention, the following first and second developers can also be used successfully: First developer: water 800 ml CD 3 10 g Sodium sulfite 10 g KH₂PO₄ 20 g Sn (II) ions (as a complex compound) 0.3-3 g pH adjustment to 5.5 to 7.5; Make up to 1 liter with water Second developer water 900 ml KH₂PO₄ 30 g CD 3 0-5 g Sodium sulfite 0-5 g Sn (II) ions (as a complex compound) 0-1 g pH adjustment to 10-13 with KOH; Make up to 1 liter with water.

In addition to phosphonobutane tricarboxylic acid, ethylenediaminetetraacetic acid, oxalic acid or gluconic acid are suitable as complexing agents.

The second developer can also contain conventional development accelerators such as ethylenediamine or thioether.

Claims (9)

1. Reversal photographic process for producing positive photographic images by imagewise exposure of the light-sensitive material containing at least one silver halide emulsion layer, black and white initial development of the material, chemical fogging, color development, bleaching, fixing, washing or stabilizing and drying, in which the material differs from the The first development is transferred to the color development without any intermediate step, the first development bath contains only one or more N, N-dialkyl-p-phenylenediamine derivatives as developers and at least one tin (II) complex compound and is adjusted to a pH <8, and that Color development bath also contains only one or more N, N-dialkyl-p-phenylenediamine derivatives as developers and is adjusted to a pH> 10. 2. The method according to claim 1, characterized in that the N, N-dialkyl-p-phenylenediamine derivative in the first development bath corresponds to the formula (II)

wherein
R₁, R₂ H, optionally substituted C₁-C₄ alkyl, C₆-C₁₀ aryl and C₁-C₃ alkoxy,
R₃ H, optionally substituted C₁-C₄-alkyl, C₆-C₁₀-aryl and C₁-C₃-alkoxy, halogen,
n is 1 or 2. 3. The method according to claim 1, characterized in that the N, N-dialkyl-p-phenylenediamine derivatives the two formulas

correspond. 4. The method according to claim 1, characterized in that the concentration of the developer substances in the first development bath is in the range of 2 to 20 g / l. 5. The method according to claim 1, characterized in that the concentration of the tin (II) complex compounds in the first development bath is 0.001 to 0.05 mol / l. 6. The method according to claim 1, characterized in that carboxylic acids and phosphonic acids are used as complexing agents for the tin (II) complex compounds. 7. The method according to claim 6, characterized in that the complexing agent of the formula

wherein
R₄, R₅, R₆, R₇ are the same or different and are hydrogen, alkyl having 1 to 4 carbon atoms, hydroxyl or (CH₂) _m X, where X can be a phosphono or a carboxy group and m 0 or an integer of 1 to 4, with the proviso that at least one of the substituents R₄ to R₇ consists of or contains a phosphono group. 8. The method according to claim 1, characterized in that the first development bath contains at least one substance which prevents the reaction of the color coupler with the developer oxidation product. 9. The method according to claim 8, characterized in that the coupling reaction preventing at least one substance is used in an amount of 0.005 to 0.1 mol / l.