DE60000675T2 - Photographic color developer concentrate - Google Patents

Description

The developer solution for the development of color photographic materials, especially for the development of color photographic paper, is prepared from concentrates that contain the necessary components or is supplemented in continuous operation.

It is usual to provide three different concentrates, since certain components of the developer bath are not compatible with each other during long-term storage. For example, one concentrate contains the antioxidant, an auxiliary solvent and a whitener, a second concentrate contains the color developer substance, e.g. 4-(N-ethyl-N-2-methylsulfonylammoethyl)-2-methyl-phenylenediamine sesquisulfate (CD-3) and a third concentrate contains the buffer substance, alkali and a limescale protection agent.

There has been no lack of attempts to develop stable one-part color developer concentrates, as this can avoid handling errors when preparing or replenishing a developer solution.

There are currently two one-part concentrates on the market, a) Monoline® RA-4 CD-R from Tetenal, a two-phase concentrate with a solid, undissolved phase at the bottom and b) TriPhase® RA-4 CD-R from Trebia, a three-phase concentrate with undissolved components in the middle phase (see also US 5 891 609).

In both cases, the presence of undissolved components is disadvantageous for the handling of the concentrate. Problems can arise, particularly when preparing the regeneration solution, because the undissolved components are difficult to dissolve. It is also disadvantageous to produce one-part concentrates that do not contain any undissolved components but darken during storage.

The object of the invention was to provide a one-part, aqueous concentrate for a color developer which contains no undissolved components and does not darken during storage.

This object is achieved in that the aqueous concentrate contains at least one color developing agent, at least one auxiliary solvent, alkali, a buffer substance and an antioxidant, wherein the antioxidant is a mixture of 0.1 to 100, preferably 1 to 25 mmol/l hydroxylamine and 0.01 to 4, preferably 0.1 to 2 mol/l of one or more substituted hydroxylamines.

In a preferred embodiment, the concentrate contains at most 0.1 mol sulfate ions/l. For example, the color developing substance is not added to the concentrate as sulfate, as is usual with CD-3, but as phosphate, p-toluenesulfonate, chloride or as free base.

CD-3 (sesquisulfate) can also be used and the sulfate ions separated by precipitation with metal ions and filtration.

A concentrate in the sense of the invention is an aqueous preparation of which 1 part by volume is diluted with 1 to 39 parts by volume of water in order to prepare a ready-to-use solution; the concentrate contains at least 50 mmol, preferably 70 to 700 mmol of color developer substance/l.

The invention therefore relates to a one-part, optionally multi-phase color developer concentrate which contains at least one color developer substance, an auxiliary solvent, a buffer system and alkali, characterized in that the concentrate contains an antioxidant, the antioxidant being a mixture of 0.1 to 100, preferably 1 to 25 mmol/l hydroxylamine and 0.01 to 4, preferably 0.1 to 2 mol/l of one or more substituted hydroxylamines.

Furthermore, the concentrate preferably contains at least one limescale protection agent.

Water-soluble organic solvents are used in particular as auxiliary solvents.

Suitable water-soluble organic solvents are those from the series of glycols, polyglycols, alkanolamines, aliphatic and heterocyclic carbonamides, aliphatic and cyclic monoalcohols, where 50 to 95% by weight, preferably 60 to 90% by weight of the sum of water and water-soluble solvent is water.

Suitable water-soluble organic solvents are, for example, carboxamide and urea derivatives such as dimethylformamide, methylacetamide, dimethylacetamide, N,N'-dimethylurea, tetramethylurea, methanesulfonamide, dimethylethyleneurea, N-acetylglycine, N-valeramide, isovaleramide, N-butyramide, N,N'-dimethylbutyramide, N-(2-hydroxyphenyl)acetamide, N-(2-methoxyphenyl)acetamide, 2-pyrrolidinone, ε-caprolactam, acetanilide, benzamide, toluenesulfonamide, phthalimide;

aliphatic and cyclic alcohols, e.g. isopropanol, tert-butyl alcohol, cyclohexanol, cyclohexane methanol, 1,4-cyclohexanedimethanol;

aliphatic and cyclic polyalcohols, e.g. glycols, polyglycols, polywaxes, trimethyl-1,6-hexanediol, glycerin, 1,1,1-trimethylolpropane, pentaerythritol, sorbitol:

aliphatic and cyclic ketones, e.g. acetone, ethyl methyl ketone, diethyl ketone, tert-butyl methyl ketone, diisobutyl ketone, acetylacetone, acetonylacetone, cyclopentanone, acetophenol;

aliphatic and cyclic carboxylic acid esters, e.g. triethoxymethane, methyl acetate, allyl acetate, methyl glycol acetate, ethylene glycol diacetate.

Glycerol 1-acetate, glycerine diacetate, methylcyclohexyl acetate, salicylic acid methyl ester, salicylic acid phenyl ester;

aliphatic and cyclic phosphonic acid esters, e.g. methylphosphonic acid dimethyl ester, allylphosphonic acid diethyl ester;

aliphatic and cyclic oxy alcohols, e.g. 4-hydroxy-4-methyl-2-pentanone, salicylaldehyde;

aliphatic and cyclic aldehydes, e.g. acetaldehyde, propanal, trimethylacetaldehyde, crotonaldehyde, glutaraldehyde, 1,2,5,6-tetrahydrobenzaldehyde, benzaldehyde, benzenepropane, terephthalaldehyde;

aliphatic and cyclic oximes, e.g. butanone oxime, cyclohexanone oxime;

aliphatic and cyclic amines (primary, secondary or tertiary), e.g. ethylamine, diethylamine, triethylamine, dipropylamine, pyrrolidine, morpholine, 2-aminopyrimidine;

aliphatic and cyclic polyamines (primary, secondary or tertiary), e.g. ethylenediamine, 1-amino-2-diethylaminoethane, methyl-bis-(2-methylammo-ethyl)amine. permethyldiethylenetriamine, 1,4-cyclohexanediamine, 1,4-benzenediamine;

aliphatic and cyclic hydroxyamines, e.g. B. ethanolamine, 2-methylethylamine, 2-methylaminoethanol, 2-(dimethylamino)ethanol, 2-(2-dimethylamino-ethoxy)-ethanoi, diethanolamine, N-methyldiethanolamine, triethanolamine, 2-(2-aminoethylamino)-ethanol, triisopropanolamine , 2-amino-2-hydroxymethyl-1,3-propanediol 1-piperidineethanol, 2-aminophenol, barbituric acid, 2-(4-aminophenoxy)-ethanol 5-amino-1-naphthol.

The processing conditions, suitable colour developers, suitable buffer substances, suitable limescale inhibitors, suitable whiteners, auxiliary developers, Wetting agents, development accelerators and antifogging agents are described in Research Disclosure 37 038 (February 1995), pages 102 to 107.

Multiphase means that the concentrate contains two or more liquid phases, but no precipitation. The liquid phases are, for example, an aqueous and an organic phase.

Suitable substituted hydroxylamines correspond to the formulas (I), (II) and (III).

in the

R₁ is optionally substituted alkyl,

R₂ is optionally substituted alkyl or optionally substituted aryl and

n 0 or 1

preferably those in which at least one of the radicals R and R contains at least one -OH, -COOH or -SO₃H group;

in the

R₃ represents an optionally substituted alkyl or optionally substituted acyl group;

in the

R₄ is an alkylene group optionally interrupted by O atoms and

m is a number of at least 2.

The alkyl groups R₁, R₂, R₃, the alkylene group R₄ and the aryl group R₂ can have further substituents in addition to the indicated substitution.

Examples of suitable antioxidants are

(0-3) CH3 CH(CH3 )NHOH

When the concentrate is diluted with water to produce the ready-to-use color developer or replenisher, any existing phase boundaries disappear; the ready-to-use developer is single-phase.

For storage, 200 ml of concentrate are filled into a 250 ml beaker (tall form) and the beaker is sealed with an airtight film (e.g. PARAFILM "M"® from American National Can, Chicago). It is stored for two months at room temperature or four weeks at 40ºC.

Examples Example 1 (comparison)

The following components of a color developer replenisher are combined in a concentrate (the ready-to-use replenisher is made from the concentrate by diluting it with water):

One-part, emphatic developer concentrate

Diethylhydroxylamine, 85 wt.% aqueous solution (DEHX solution) 35 ml

CD 3, Base 31 g

Diethylene glycol 30 ml

Whitener W1 2g

Ethylenediaminetetraacetic acid (EDTA) 10 g

Potassium carbonate 60 g

Adjust pH to 13.5 with KOH and top up to 1 liter with water.

The concentrate darkens considerably during storage.

Example 2 (comparison) One-part, emphatic developer concentrate

Antioxidant O-2 35 g

CD3, Base 31g

Diethylene glycol 30 ml

Whitener W1 2g

EDTA 10g

Potassium carbonate 60 g

Adjust pH to 13.5 with KOH and top up to 1 liter with water.

The concentrate darkens considerably during storage.

Example 3 (comparison) One-part, single-phase developer concentrate

DEHX solution 35 ml

Sodium sulphite 0.5 g

CD3, Base 31 g

Diethylene glycol 30 ml

Whitener 2 g

Polymaleic anhydride, 50 wt.% aqueous solution 15 m

Potassium carbonate 60 g

Adjust to pH 13.5 with KOH and top up to 1 liter with water.

The concentrate darkens considerably during storage.

Example 4 (comparison) One-part, single-phase developer concentrate

DEHX solution 35 ml

Sodium sulphite 2 g

CD3, Base 31 g

Diethylene glycol 30 ml

Whitener 2 g

EDTA 10g

Potassium carbonate 60 g

Adjust to pH 13.5 with KOH and top up to 1 liter with water.

The concentrate darkens considerably during storage.

Example 5 (according to the invention) One-part, emphatic developer concentrate

DEHX solution 35 ml

CD-3, Base 31g

Hydroxylammonium sulfate 0.5 g

Diethylene glycol 30 ml

Whitener 2 g

EDTA 10g

Potassium carbonate 60 g

Adjust pH to 13.5 with KOH and top up to 1 liter with water.

The concentrate is light yellow and does not darken during storage.

Example 6 (according to the invention) One-part, single-phase developer concentrate

Antioxidant O-2 35 g

Hydroxylammonium sulfate 0.5 g

CD3, Base 31g

Diethylene glycol 30 ml

Whitener 2 g

EDTA 10g

Potassium carbonate 60 g

Adjust pH to 13.5 with KOH and top up to 1 liter with water.

The concentrate is light yellow and does not darken during storage.

Example 7 (Comparison) One-part, multi-phase developer concentrate

DEHX solution 60 ml

CD-3, Base 45 g

Caprolactam 100g

Triethanolamine 80 ml

Whitener 10 g

Diethylenetriaminepentaacetic acid 40 g

Potassium carbonate 165 g

KOH 42 g

Adjust to pH 11.2 with KOH and top up to 1 l with water.

The upper phase of the concentrate darkens considerably during storage.

Example 8 (comparison) One-part, multi-phase developer concentrate

DEHX solution 60 ml

Sodium sulphite 2 g

CD-3, Base 45 g

Caprolactam 100g

Triethanolamine 80 ml

Whitener 10 g

EDTA 30g

Potassium carbonate 165 g

KOH 42 g

Adjust to pH 11.2 with KOH and top up to 1 l with water.

The upper phase of the concentrate darkens considerably during storage.

Example 9 (according to the invention) One-part, multi-phase developer concentrate

DEHX solution 60 ml

Hydroxylammonium sulfate 0.6 g

CD-3, Base 45 g

Caprolactam 100g

Triethanolamine 80 ml

Whitener 10 g

EDTA 30g

Potassium carbonate 165 g

KOH 42 g

Adjust to pH 11.2 with KOH and top up to 1 l with water.

The upper phase of the concentrate is light yellow and does not darken during storage.

Example 10

A color photographic recording material is produced by applying the following layers in the order given to a layer support made of paper coated on both sides with polyethylene. The quantities given refer to 1 m². The corresponding quantities of AgNO₃ are given for the silver halide application.

Layer structure 1 1st layer (substrate layer)

0.1 g gelatine

2nd layer (blue-sensitive layer)

blue-sensitive silver halide emulsion (99.5 mol% AgCl, 0.5 mol%

AgBr, average grain diameter 0.9 um) from

0.50 g gelatine

0.42 g yellow coupler GB-1

0.18 g yellow coupler GB-2

0.50 g tricresyl phosphate (TKP)

0.10 Stabilizer ST-1

3rd layer (intermediate layer)

1.1 g gelatine

0.06g Scavenger SC-1

0.06g Scavenger SC-2

0.12 g CPM

4th layer (green-sensitive layer)

green-sensitive silver halide emulsion (99.5 mol% AgCl, 0.5 mol%

AgBr, average grain diameter 0.47 um) from

0.40 g AgN0₃

0.77 g gelatine

0.21 g purple coupler PP-1

0.15 g purple coupler PP-2

0.05 g purple coupler PP-3

0.06 g Color Stabilizer ST-2

0.12g Scavenger SC2

0.23 g dibutyl phthalate

5th layer (UV protection layer)

1.15 g gelatine

0.03g Scavenger SC-1

0.03g Scavenger SC-2

0.5 g UV absorber UV-1

0.10 g UV absorber ÜV-2

0.35 g CPM

6th layer (red-sensitive layer)

red-sensitive silver halide emulsion (99.5 mol% AgCl, 0.5 mol% AgBr,

average grain diameter 0.5 um) from

0.30 g AgNOs with

1.0 g gelatine

0.40 g Blue-Green Coupler B G-1

0.05 g Blue-Green Coupler BG-2

0.46 g CPM

7th layer (UV protection layer)

0.35 g gelatine

0.15g UV-1

0.03g UV-2

0.09 g CPM

8th layer (protective layer)

0.9 g gelatine

0.3 g hardener HM

0.05 g Whitener W-1

0.07 g vinylpyrrolidone

1.2 mg silicone oil

2.5 mg polymethyl methacrylate beads with average particle diameter 0.8 µm

The colour photographic recording material is exposed and processed under the following conditions:

Ready-to-use developers made from the concentrates according to Examples 1 to 9 are used as color developers.

Bleach-fix bath

Ammonium thiosulfate solution, 58 wt.% 100 ml

Sodium disulphite 5 g

Ammonium iron EDTA, 48 wt.% 100 ml

Fill with water to 1000 ml, adjust pH to 6.0 with ammonia or acetic acid.

Stabilizing bath

Water 900 ml

Sodium sulphite 2 g

Hydroxyethanediphosphonic acid disodium salt 4 g

Sodium benzoate 0.5 g

Fill up to 1000 ml with water and adjust pH to 5 with acetic acid.

dry

The images produced show no significant differences in their sensitometric properties.

Claims (6)

1. One-part, optionally multi-phase color developer concentrate which contains at least one color developer substance, at least one auxiliary solvent, an antioxidant, a buffer system and alkali, characterized in that the antioxidant is a mixture of 0.1 to 100 mmol/l hydroxylamine and 0.01 to 4 mol/l of one or more substituted hydroxylamines. 2. Color developer concentrate according to claim 1, characterized in that it contains as auxiliary solvent one or more water-soluble organic solvents, wherein 50 to 95% by weight of the sum of water and solvent is water. 3. Color developer concentrate according to claim 1, characterized in that the color developer substance is 4-(N-ethyl-N-2-methylsulfonylaminoethyl)-2-methylphenylenediamine. 4. One-part colour developer concentrate according to claim 1, characterized in that the substituted hydroxylamine corresponds to one of the formulas (I), (II) or (III): in the R₁ is optionally substituted alkyl, R₂ is optionally substituted alkyl or optionally substituted aryl and n means 0 or 1; in the R₃ represents an optionally substituted alkyl or optionally substituted acyl group; in the R₄ is an alkylene group optionally interrupted by O atoms and m is a number of at least 2. 5. One-part color developer concentrate according to claim 1, characterized in that it contains at most 0.1 mol of sulfate ions/l. 6. One-part color developer concentrate according to claim 1, characterized in that it contains at most 0.05 mol of sulfate ions/l.