DE19712694A1 - Low odour polymeric antioxidant, inhibiting tar formation in colour developer bath without impairing kinetics or whites - Google Patents

Abstract

Polymeric antioxidants (I) with monomer unit(s) of formula (IA) or (IB) are new; where X = H or OH; R1-R3 = H or alkyl; and R4 = H, alkyl or acyl. The H:OH ratio of X is (3-0):1; and the average molecular weight of (I) is >= 400. Preferably the bath contains 0.5-10 g/l (I). The colour developer is a p-phenylene diamine compound.

Description

The invention relates to a low-odor developer bath and a processing method ren for silver halide color photographic material using this Ent winder bath.

It is known that when developing a silver halide photographic material Developmental silver halide crystals are reduced to silver. At the chromogenic development, the color formation takes place simultaneously by the oxidizing te color developer in a subsequent reaction with those in the emulsion layer Coupling components reacted to organic dyes.

The most common color developers include the derivatives of p-phenylenedi amines. Usually used as antioxidants for these substances Hydroxylamine, N, N-diethylhydroxylamine or N, N-bis (2-sulfoethyl) hydroxylamine used (US-A-5 354 646). The former is preferably used in the Ver processing of color recording materials with camera sensitivity, the last two ren are preferably used in the processing of copy materials.

A disadvantage when using the particularly frequently used in developer baths N, N-diethylhydroxylamine is a strong odor nuisance due to this substance contained baths.

This applies in particular to modern rapid processing processes, the ge are characterized by high temperature processing and low regeneration quo due to both high bath temperatures and increasing substance concentrations intensify the smell problem in said bathrooms. Fast processing processes in turn, are preferably used in so-called minilabs. These are often Without an exhaust air connection directly in the shop, so that it can escape from the bathrooms de Smell not only annoys the operator himself, but also the customers.

Various low odor antioxidants have been developed recently (US-A-5 466 565, US-A-5 508 155, US-A-5 554 493, WO 96/28761).  

In addition to the lowest possible odor nuisance and an effective prevention of oxidation of the color developer, other requirements are placed on modern antioxidants. These requirements include:

• - effective protection against the developer bath becoming more expensive,
• - no impairment of developmental kinetics,
• - no deterioration in image whiteness.

The previously known antioxidants do not yet meet all of the requirements mentioned changes.

The invention is therefore based on the object of a developer bath for processing to produce color photographic materials that are as odorless as possible. Except the other requirements mentioned should also be met.

It has now been found that the above objects are achieved with a developer lerbad be solved according to claim 1.

The invention relates to a developer bath for an exposed color photographic silver halide material with a color developer substance and a polymeric antioxidant, characterized in that the polymeric antioxidant tel at least one monomer unit I or II

contains what
X is hydrogen or -OH,
R ₁ , R ₂ , R _{3 are} hydrogen or alkyl and
R _{4 is} hydrogen, alkyl or acyl,
and wherein the ratio hydrogen to -OH is from X 3: 1 to 0: 1 and the polymeric antioxidant has an average molecular weight M of at least 400.

An alkyl radical represented by R ₁ to R ₄ or contained therein can be straight-chain or branched; it is preferably an alkyl radical having 1 to 4 carbon atoms.

If R ₄ is an acyl radical, it is preferably derived from an aliphatic carboxylic or sulfonic acid, from carbonic acid or carbamic acid.

In a preferred embodiment of the invention in the monomer units I and II
R ₁ and R _{3 are} hydrogen,
R _{2 is} hydrogen or methyl and
R _{4 is} hydrogen, methyl, ethyl, propyl or isopropyl.

In a particularly preferred embodiment of the invention in the monomer units I and II
R ₁ and R _{3 are} hydrogen,
R ₂ and R _{4 are} hydrogen or methyl,
and for X the ratio of hydrogen to -OH is 1: 1 to 0: 1.

Another part of the invention relates to that of at least one of the monomer units ten I and II built polymeric antioxidants.

Examples of suitable compounds according to the invention are given below ben.

Polyallylamines are commercially available. The oxidation to the corresponding polymeric hydroxylamines are made with hydrogen peroxide.

Synthesis of compound 1

570 g of a 10% strength by weight aqueous solution of polyallylamine (M = 100,000) are mixed with 48.5 g of a 35% strength by weight aqueous H ₂ O ₂ solution at 60 ° C. within 15 minutes. The mixture is stirred for a further 1 hour at 60 ° C. and 359 g of water are distilled off in vacuo. A 25% by weight aqueous, pale yellow solution of compound 1 is thus obtained.

Synthesis of compound 2

570 g of a 10% strength by weight aqueous solution of polyallylamine (M = 100,000) are mixed with 97 g of a 35% strength by weight aqueous H ₂ O ₂ solution at 60 ° C. within 30 minutes. The mixture is stirred for a further 2 hours at 60 ° C. and 375 g of water are distilled off in vacuo. A 25% by weight aqueous, light yellow solution of compound 2 is thus obtained.

Synthesis of compound 3

The synthesis of 3 is carried out analogously to the synthesis of 2 with the difference that Polyallylamin with M = 10,000 is used.  

Synthesis of compound 12

The synthesis of 12 is carried out analogously to the synthesis of 2 with the difference that 970 g of a 10% by weight aqueous solution of polydiallylamine (M = 49,000) is used.

Synthesis of compound 14

570 g of a 10% strength by weight aqueous solution of polyallylamine (M = 10,000) are admixed with 72.8 g of a 35% strength by weight aqueous H ₂ O ₂ solution at 60 ° C. within 25 minutes. The mixture is stirred for a further 1.5 hours at 60 ° C. and 367 g of water are distilled off in vacuo. A 25% by weight aqueous, pale yellow solution of compound 14 is thus obtained.

Usually the polymeric antioxidants are used in one concentration from 0.1 to 30 g / l used in the developer bath according to the invention.

In a preferred embodiment, the developer bath contains 0.25 to 20 g / l oxi antidote. In a particularly preferred embodiment of the invention contains the developer bath 0.5 to 10 g / l antioxidant.

Another part of the invention is a processing method for an exposed ink photographic silver halide material comprising at least the treatment steps Color development, bleaching and fixing, the steps of bleaching and fixing to Bleach-fixing step can be summarized, characterized in that for the treatment step color developing a developer bath containing one Color developer substance and on one of at least one of the monomer units I or II built polymeric antioxidant is used.

Examples of color photographic materials using the inventive method can be processed are color negative films, color reversal films, color positive films,  color photographic paper, color reversal photographic paper, color sensitive materia lien for the color diffusion transfer process or the silver color bleaching process.

The method according to the invention is particularly well suited for processing color photographic silver halide materials with a silver halide content ≧ 80 mol% AgCl.

The photographic materials consist of a support on which at least one photosensitive silver halide emulsion layer is applied. Suitable as a carrier especially thin films and foils. An overview of substrates and auxiliary layers applied to their front and back are in Research Disclosure 37 254, Part 1 (1995), p. 285.

The color photographic materials usually contain at least one each in red sensitive, green-sensitive and blue-sensitive silver halide emulsion layer and, if necessary, intermediate layers and protective layers.

Depending on the type of photographic material, these layers can be arranged differently. This is shown for the most important products:
Color photographic films such as color negative films and color reversal films have 2 or 3 red-sensitive, blue-green coupling silver halide emulsion layers, 2 or 3 green-sensitive, purely coupling silver halide emulsion layers and 2 or 3 blue-sensitive, yellow coupling silver halide emulsion layers on the support in the order given below. The layers of the same spectral sensitivity differ in their photographic sensitivity, the less sensitive sub-layers generally being arranged closer to the support than the more sensitive sub-layers.

Between the green sensitive and blue sensitive layers is common a yellow filter layer is applied, which prevents blue light from lying in the below layers.  

Color photographic paper, which is usually much less sensitive to light than a color photographic film shows in the order given below the carrier usually each a blue-sensitive, yellow-coupling silver halide emulsion layer, a green-sensitive, purple-coupling silver halide emulsion layer and a red-sensitive, cyan-coupling silver halide emulsion layer on; the yellow filter layer can be omitted.

Deviations in the number and arrangement of the light-sensitive layers can lead to Achieve certain results. For example, everyone highly sensitive layers to form a layer package and all low-sensitivity layers Layers together to form another layer package in a photographic film be summarized to increase the sensitivity (DE 25 30 645).

The possibilities of the different layer arrangements and their effects the photographic properties are described in J. Inf. Rec. Mats., 1994, Vol. 22, Pages 183-193.

Essential components of the photographic emulsion layers are binders, Silver halide grains and color couplers.

Information on suitable binders can be found in Research Disclosure 37 254, Part 2 (1995), p. 286.

Information about suitable silver halide emulsions, their preparation, maturation, stabilization lization and spectral sensitization including suitable spectral sensitivities sators can be found in Research Disclosure 37 254, Part 3 (1995), p. 286, and in Research Disclosure 37 038, Part XV (1995), p. 89.

Photographic materials with camera sensitivity usually contain silver bromide iodide emulsions, which may also contain small amounts of silver chloride can hold. Photographic copying materials contain either silver chloride  bromide emulsions with up to 80 mol% AgBr or silver chloride bromide emulsions with over 95 mol% AgCl.

Information on the color couplers can be found in Research Disclosure 37 254, Part 4 (1995), p. 288, and in Research Disclosure 37 038, Part II (1995), p. 80. Die maximum absorption of the from the couplers and the color developer oxidation pro Dyes formed in the product are preferably in the following areas: yellow clutch 430 to 460 nm, magenta couplers 540 to 560 nm, cyan couplers 630 to 700 nm.

In color photographic films, to improve sensitivity, grainy speed, sharpness and color separation are often used in the compounds involved in the reaction release compounds with the developer oxidation product that have a photographic effect are sam, e.g. B. DIR couplers that release a development inhibitor.

Information on such compounds, in particular couplers, can be found in Research Disclosure 37 254, Part 5 (1995), p. 290 and in Research Disclosure 37 038, Part XIV (1995), p. 86.

The mostly hydrophobic color coupler, but also other hydrophobic components of the Layers are usually dissolved in high-boiling organic solvents or dispersed. These solutions or dispersions are then in an aqueous Binder solution (usually gelatin solution) emulsified and lie after Drying the layers as fine droplets (0.05 to 0.8 µm diameter) in the Layers before.

Suitable high-boiling organic solvents, methods for incorporation into the Layers of photographic material and other methods, chemical compound Introducing solutions into photographic layers can be found in Research Disclosure 37 254, Part 6 (1995), p. 292.

The usually indicated between layers of different spectral sensitivity ordered non-photosensitive interlayers can contain agents that have a  unwanted diffusion of developer oxidation products from a photosensitive chen in another light-sensitive layer with different spectral Sen prevent sensitization.

Suitable connections (white coupler, scavenger or EOP catcher) can be found in Research Disclosure 37 254, Part 7 (1995), p. 292 and in Research Disclosure 37 038, Part III (1995), p. 84.

The photographic material can also contain UV light-absorbing compounds, whiteners, spacers, filter dyes, formalin scavengers, light stabilizers, anti-oxidants, D _min dyes, additives to improve the stability of dyes, couplers and whites as well as to reduce the color fog, plasticizers (latices) , Biocide and others included.

Suitable compounds can be found in Research Disclosure 37 254, Part 8 (1995), p. 292 and in Research Disclosure 37 038, Parts IV, V, VI, VII, X, XI and XIII (1995), P. 84 ff.

The layers of color photographic materials are typically hardened, i.e. that is binder used, preferably gelatin, is by suitable chemical Ver networked.

Suitable hardener substances can be found in Research Disclosure 37 254, Part 9 (1995), P. 294 and in Research Disclosure 37 038, Part XII (1995), p. 86.

After photographic exposure, color photographic materials become their character processed according to different processes. Color negative materials become through color development, bleaching, fixing and watering, color reversal material lien by black-and-white development, blurring, color development, bleaching, fixie water and processed.  

The bleaching and fixing steps can be combined to form the bleach-fixing step be sane. The final irrigation can be replaced by a stabilization in which unwanted chemicals no longer watered out, but in harmless compounds implementations. Between individual baths can be intermediate waterings be made.

The processing is for the usual materials regarding developer binding, duration of the individual steps, pH of the baths, temperature of the baths largely standardized. Deviations are possible.

Color developer substances are preferably p-phenylenediamine compounds, e.g. B. 1- (N-ethyl-N-methanesulfonamidoethyl) -3-methyl-p-phenylenediamine, 1- (N-ethyl-N-hy hydroxyethyl) -3-methyl-p-phenylenediamine and 1-N-ethyl-N-hydroxypropyl-3-me thyl-p-phenylene diamine and 1-N-ethyl-N-hydroxybutyl-3-methyl-phenyl diamine (EP-A-410 450). Further useful color developers are described, for example, in J. Amer. Chem. Soc. 73, 3106 (1951) and G. Haist, Modern Photographic Processing, 1979, John Wiley and Sons, New York, pages 545 ff. And in US-A-5 278 034, US-A-5 264 331, EP-A-727 708 and EP-A-731 380.

The concentration of the developer compound is 1 to 15 g / l, preferably about 3 to 8 g / l, the development time 10 s to 5 min, preferably 15 s to 1 min, the pH of the developer bath 9 to 11, the development temperature of the developer solution 30 to 45 ° C, preferably 35 to 40 ° C. For ecological reasons, the regeneration rate should be as low as possible, particularly preferably 40 to 1100 ml / m ^{2 of} material.

Details on the procedures and chemicals required for this are given in Research Disclosure 37 254, Part 10 (1995), p. 294 and in Research Disclosure 37 038, parts XVI to XXIII (1995), p. 95 ff. Together with exemplary Materials released.

example

A color developer solution is produced according to the following recipe:

Developer bath I

Tetraethylene glycol 20.0 g Antioxidant V-1 4.0 g Color developer CD-3 5.0 g Potassium sulfite 0.2 g Potassium carbonate 30.0 g Polymaleic anhydride 2.5 g Hydroxyethane diphosphonic acid 0.2 g White toner (4,4'-diamino-2,2'-stilbene disulfonic acid derivative 2.0 g Potassium bromide 20.0 mg

make up to 1000 ml with water and pH with KOH or H ₂

SO _4th

to 10.2 to adjust.

Developer baths 2 to 8

Baths 2 to 8 differ from bath 1 in that they are exchanged in the same quantity of the antioxidant V-I with the compounds shown in Table 1.

After the developer baths have been produced, the CD-3 content gradually increases 28 days storage at 20 ° C determined and the discoloration of the baths by increasing visual increase (see Table 1). The freshly set baths are also warmed to 35 ° C and assessed for their smell (see table 1).  

Furthermore, a color photographic recording material is produced by applying the following layers in the order given to a support made of paper coated on both sides with polyethylene. The quantities given relate to 1 m ² . The corresponding amounts of AgNO ₃ are given for the silver halide application.

Layer structure Layer 1 (substrate layer)

0.10 g gelatin

Layer 2 (blue sensitive layer)

Blue-sensitive silver halide emulsion (99.5 mol% chloride, 0.5 mol% bromide, average grain diameter 0.9 µm) from 0.50 g AgNO ₃

, With
1.25 g gelatin
0.42 g gel coupler Y-1
0.18 g yellow coupler Y-2
0.50 g of oil former OF-1
0.10 g stabilizer ST-1
0.70 mg blue sensitizer BS-1
0.30 mg stabilizer ST-2

Layer 3 (intermediate layer)

1.10 g gelatin
0.06 g EOP catcher EF-1
0.06 g EOP catcher EF-2
0.12 g tricresyl phosphate (CPM)

Layer 4 (green sensitive layer)

green-sensitive silver halide emulsion (99.5 mol% chloride, 0.5 mol% bromide, average grain diameter 0.47 µm) from 0.28 g AgNO ₃

, With
1.10 g gelatin
0.25 g purple coupler M-1
0.18 g stabilizer ST-3
0.12 g stabilizer ST-4
0.70 mg green sensitizer GS-1
0.50 mg stabilizer ST-5
0.25 g of oil former OF-2
0.25 g of OF-3 oil generator

Layer 5 (UV protective layer)

0.95 g gelatin
0.30 g UV absorber UV-1
0.06 g EOP catcher EF-1
0.06 g EOP catcher EF-2
0.15 g of oil former OF-4
0.15 g CPM

Layer 6 (red sensitive layer)

red-sensitive silver halide emulsion (99.5 mol% chloride, 0.5 mol% bromide, average grain diameter 0.5 µm) from 0.30 g AgNO ₃

, With
1.0 g gelatin
0.46 g of cyan coupler C-1
0.46 g CPM
0.03 mg red sensitizer RS-1
0.60 mg stabilizer ST-6
0.30 g UV absorber UV-2

Layer 7 (UV protective layer)

0.30 g gelatin
0.10 g UV absorber UV-3
0.10 g of oil former OF-2

Layer 8 (protective layer)

0.90 g gelatin
0.05 g white toner WT-1
0.07 g stain (polyvinylpyrrolidone)
1.20 mg silicone oil
2.50 mg spacer (polymethyl methacrylate, medium particle size 0.8 µm)
0.30 g of H-1 curing agent

Samples of this CN paper are exposed through a gray wedge, whereby color filters are brought into the beam path in such a way that a neutral gray color reproduction is achieved when processed in a typical manner at density D = 0.6. One sample each in a freshly prepared developer bath, and another in the developer bath then stored for 28 days, are developed and processed under the specified conditions. Then the differences in the yellow haze (ΔD _min ), in the yellow maximum density (ΔD _max ) and the yellow gradation (ΔG) are determined and the image whiteness of the samples developed with stored developer bath is assessed visually (see Table 1).

The exposed material is processed according to the following scheme:

The color developer used was:

Bleach-fixer

Ammonium thiosulfate 75.0 g Sodium bisulfite 13.5 g Fe-NH ₄ -EDTA 45.0 g

make up to 1000 ml with water and adjust to pH with ammonia or acetic acid Set 6.0.  

As Table 1 shows, the antioxidants according to the invention are important parameters such as image whitening and yellow sensitometry of the best comparison compound V-1 equivalent, but without causing a significant odor nuisance like V-1 stuff.

Connections used in the example:

Claims (8)

1. developer bath for an exposed color photographic silver halide material with a color developer substance and a polymeric antioxidant, characterized in that the polymeric antioxidant we least one monomer unit I or II
contains what
X is hydrogen or -OH,
R ₁ , R ₂ , R _{3 are} hydrogen or alkyl and
R _{4 is} hydrogen alkyl or acyl,
and wherein the ratio hydrogen to -OH is from X 3: 1 to 0: 1 and the polymeric antioxidant has an average molecular weight M of at least 400. 2. Developer bath according to claim 1, characterized in that in the mono mer units I and II
R ₁ and R _{3 are} hydrogen,
R ₂ and R ₄ denote hydrogen or methyl,
and for X the ratio of hydrogen to -OH is 1: 1 to 0: 1. 3. developer bath according to one of claims 1 or 2, characterized in that it is the polymeric antioxidant in a concentration of 0.5 to Contains 10 g / l. 4. developer bath according to claim 1, characterized in that it as Farbent contains a p-phenylenediamine compound. 5. Processing method for an exposed color photographic silver halide material, comprising at least the treatment steps color development, lead Chen and fix, the steps of bleaching and fixing to the step Bleach-fixing can be summarized, characterized in that for the treatment step color developing a developer bath containing a color developer substance and one of at least one of the mono Use polymeric antioxidants built up in units I or II det. 6. The method according to claim 5, characterized in that it is a Ver Working method for an exposed color photographic silver halide mate rial with a silver halide content of ≧ 80 mol% AgCl. 7. Polymeric antioxidants, characterized in that they have at least one monomer unit I or II
included in what
X is hydrogen or -OH,
R ₁ , R ₂ , R _{3 are} hydrogen or alkyl and
R _{4 is} hydrogen, alkyl or acyl,
and wherein the ratio hydrogen to -OH is from X 3: 1 to 0: 1 and the polymeric antioxidant has an average molecular weight M of at least 400. 8. Polymeric antioxidant according to claim 7, characterized in that in the monomer units I and II
R ₁ and R _{3 are} hydrogen,
R ₂ and R ₄ denote hydrogen or methyl,
and for X the ratio of hydrogen to -OH is 1: 1 to 0: 1.