A one-part color developer concentrate which comprises at least two phases and which is free from precipitates at 20° C., which contains at least one color developer substance, at least one antioxidant, at least one anti-lime agent, a buffer system and alkali, one phase of which is aqueous and the other phase of which is organic, wherein the aqueous phase has a pH of at least 9, is obtained when the concentrate has a concentration of cations from 0.5 to 15 mol/l, wherein at least 10 mol % of the cations are sodium ions and the organic phase is formed from one or more water-soluble solvents, and wherein 50 to 95% by weight of the sum of water and water-soluble solvents is water.
Description
The developer solution which is used for the development of colour photographic materials, particularly for the development of colour photographic paper, is made up from or is regenerated in continuous operation by concentrates which contain the necessary constituents.
It is customary to provide three different concentrates, since certain constituents of the developer bath are incompatible with each other on storage for an extended period. Thus, for example, one concentrate may contain the antioxidant, an auxiliary solvent and an optical brightener, a second concentrate may contain the colour developer substance, e.g. CD 3 4-(N-ethyl-N-2-methylsulphonylaminoethyl)-2-methyl-phenylenediamine sequisulphate and a third concentrate may contain the buffer substance, alkali and an anti-lime agent.
There has been no lack of attempts aimed at developing stable, one-part colour developer concentrates, since errors in handling, making up or regenerating a developer solution could thereby be avoided.
Currently, there are two one-part concentrates on the market: a) Monoline® RA-4 CD-R manufactured by Tetenal, a two-phase concentrate with an undissolved, solid phase lying on the bottom, and b) Tri Phase® RA-4 CD-R manufactured by Trebla, a three-phase concentrate with undissolved constituents in the middle phase (see U.S. Pat. No. 5,891,609 also).
In both these cases, the presence of undissolved constituents constitutes a disadvantage with regard to the handling of the concentrates. Problems can arise in particular when making up the regenerator solution, because the undissolved constituents can only be dissolved with difficulty.
The object of the present invention was to provide a one-part concentrate for a colour developer which contains no undissolved constituents and from which a regenerator solution can be prepared rapidly.
This object is achieved in that apart from the customary chemicals which are necessary for the development of a colour photographic material the concentrate contains a minimum amount of one or more water-soluble auxiliary solvents and a minimum amount of sodium ions, both in absolute terms and in relation to the other cations.
A concentrate in the sense of the invention is an aqueous preparation, one part by volume of which 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 colour developer substance per liter.
The present invention therefore relates to a one-part colour developer concentrate which contains at least one colour developer substance, at least one antioxidant, at least one anti-lime agent, a buffer system and alkali, has a ph of at least 9 and a concentration of cations from 0.5 to 15 mol/l, wherein at least 10 mol %, preferably at least 30 mol %, most preferably at least 50 mol % of the cations arc sodium ions and contains at least 50 mmol colour developer substance per liter.
The concentrate comprises one phase or more than one phase, preferably two phases. At least one phase is an organic phase and one is an aqueous phase, the organic phase containing one or more w,water-soluble organic solvents wherein 50 to 95 %, preferably 60 to 90 %, by weight of the sum of organic solvents and water are water.
Examples of suitable water-soluble solvents include derivatives of carboxylic acid amides and derivatives of urea, such as dimethylformamide, methylacetamide, di-methylacetamide, N,N′-climethylurea, tetramethylurea, methanesulphonic acid amide, 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, toluenesulphonic acid amide, phthalimide;
aliphatic and cyclic alcohols, e.g. isopropanol, tert.-butyl alcohol, cyclohexanol, cyclohexanemethanol, 1,4-cyclohexanedimethanol;
aliphatic and cyclic polyalcohols, e.g. glycols, polyglycols, polymer waxes, trimethyl-1,6-hexanediol, glycerol, 1,1,1-trimethylolpropane, pentaerythritol, sorbitol;
aliphatic and cyclic ketones, e.g. acetone, methyl ethyl ketone, diethyl ketone, tert.-butyl methyl ketone, diisobutyl ketone, acetylacetone, acetonylacetone, cyclopentanone, acetophenone;
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, benzenepropanal, terephthalaldehyde;
aliphatic and cyclic oximes, e.g. butanone oxime, cyclohexanone oxime;
aliphatic and cyclic amines (primary, secondary or tertiary) e.g. ethylamine, di-ethylamine, triethylamine, dipropylamine, pyrrolidine, morpholine, 2-aminopyrimidine;
aliphatic and cyclic polyamines (primary, secondary or tertiary), e.g. ethylenediamine, 1-amino-2-dimethylaminoethane, methyl-bis-(2-methylamino-ethyl)amine, permethyl-diethylenetriamine, 1,4-cyclohexanediamine, 1,4-benzenediamine;
Good phase separation is achieved with the aforementioned solvents, either individually or in admixture.
Processing conditions, suitable colour developer substances, suitable buffer substances, suitable anti-lime agents, suitable optical brighteners, auxiliary developers, wetting agents, crosslinking agents, development accelerators and anti-fogging agents are described in Research Disclosure 37 038 (February 1995) on pages 102 to 107.
4-(N-ethyl-N-2-methylsulphonylaminoethyl)-2-methyl-phenylenediamine sesquisulphate (CD-3) and 4-(N-Ethyl-N-2-hydroxyethyl)-2-methyl-phenylenediamine sulfate (CD-4) are preferred as the colour developing substances.
Suitable antioxidants are compounds of formulae (I), (II) and (III)
wherein
R 1
denotes unsubstituted or substituted alkyl,
R 2
denotes unsubstituted or substituted alkyl or aryl, and
n denotes 0 or 1,
preferably those in which at least one of the R 1
and R 2
radicals contains at least one —OH, —COOH or —-SO 3
H group;
wherein
R 3
denotes an alkyl or acyl group;
wherein
R 4
denotes an alkylene group which is optionally interrupted by O atoms, and
m denotes a number of at least 2.
The alkyl groups R 1
, R 2
, R 3
, the alkylene group R 4
and the aryl group R 2
can comprise further substituents in addition to the aforementioned substituents.
Examples of suitable antioxidants include:
When the concentrate is diluted with water in order to prepare the ready-to-use colour developer or regenerator, the phase boundaries disappear; the ready-to-use developer is monophase.
EXAMPLES
EXAMPLE 1
Comparison
The usual constituents of a colour developer regenerator were mixed together in a concentrate (the ready-to-use regenerator was prepared from the concentrate by dilution with water):
One-part developer concentrate:
diethylhydroxylamine, 85% by weight aqueous solution
60
ml
(DEHX sln.)
CD3
70
g
caprolactam
100
g
triethanolamine
80
ml
optical brightener
10
g
ethylenediaminetetraacetic acid (EDTA)
30
g
potassium carbonate
300
g
potassium hydroxide
30
g
made up to 1 liter with water.
The cation concentration (Na +
, K +
) amounted to 4.9 mol/l, of which 0 mol % was Na 30
ions.
The concentrate formed 3 phases, the middle phase contained undissolved constituents.
EXAMPLE 2
Comparison
One-part developer concentrate:
DEHX sln.
60
ml
CD3
70
g
p-toluenesulphonic acid
100
g
diethylene glycol
80
ml
optical brightener
10
g
EDTA
30
g
potassium carbonate
300
g
potassium hydroxide
30
g
made up to 1 liter with water.
The cation concentration (N +
, K +
) amounted to 4.9 mol/l, of which 0 mol % was Na +
ions.
Despite the auxiliary solvents, the concentrate formed 3 phases, and the middle phase contained undissolved constituents.
EXAMPLE 3
Comparison
One-part developer concentrate:
DEHX sln.
60
ml
CD3
70
g
caprolactam
100
g
triethanolamine
80
ml
optical brightener
10
g
EDTA
30
g
potassium carbonate
200
g
potassium hydroxide
30
g
made up to 1 liter with water.
The cation concentration (Na +
, K +
) amounted to 3.4 mol/l, of which 0 mol % was Na +
ions.
Even with less potassium carbonate, the concentrate formed 3 phases, and the middle phase contained undissolved constituents.
EXAMPLE 4
Comparison
One-part developer concentrate:
DEHX sln.
60
ml
CD3
70
g
caprolactam
100
g
diethylene glycol
80
ml
optical brightener
10
g
EDTA
30
g
potassium carbonate
300
g
potassium hydroxide
23
g
sodium hydroxide
7
g
made up to 1 liter with water.
The cation concentration (Na +
, K +
) amounted to 5.1 mol/l, of which 5 mol % was Na +
ions.
Even with a cation content corresponding to 15 mol % sodium, the concentrate formed 3 phases, and the middle phase contained undissolved constituents.
EXAMPLE 5
According to the Invention
One-part developer concentrate:
DEHX sln.
60
ml
CD3
70
g
caprolactam
100
g
diethylene glycol
80
ml
optical brightener
10
g
EDTA
30
g
potassium carbonate
140
g
sodium carbonate
18
g
sodium hydroxide
30
g
made up to 1 liter with water.
The cation concentration (Na +
, K +
) amounted to 3.1 mol/l, of which 35 mol % was Na +
ions. The pH of the aqueous phase was 11.
With a cation content corresponding to 35 mol % sodium, the concentrate formed 2 phases; both phases were completely dissolved and well separated from each other.
EXAMPLE 6
According to the Invention
One-part developer concentrate:
DEHX sln.
60
ml
CD3
70
g
polymer wax 1550 (polyethylene glycol with a
100
g
molecular weight of 1550)
diethylene glycol
80
ml
optical brightener
10
g
EDTA
30
g
potassium carbonate
100
g
sodium carbonate
50
g
sodium hydroxide
30
g
made up to 1 liter with water.
The cation concentration (Na +
, K +
) amounted to 3.1 mol/l, of which 54 mol % was Na +
ions. The pH of the aqueous phase was 11.
With a cation content corresponding to 54 mol % sodium, the concentrate formed 2 phases; both phases were completely dissolved and well separated from each other.
EXAMPLE 7
According to the Invention
One-part developer concentrate:
disulphoethylhydroxylamine (HADS)
50
g
CD3
70
g
glycerol
100
g
triethanolamine
80
ml
optical brightener
10
g
EDTA
30
g
sodium carbonate
130
g
sodium hydroxide
30
g
made up to 1 liter with water.
The cation concentration (Na +
, K +
) amounted to 3.2 mol/l, of which 100 mol % was Na +
ions. The pH of the aqueous phase was 11.
With a cation content corresponding to 100 mol % sodium, the concentrate formed 2 phases; both phases were completely dissolved and well separated from each other.
EXAMPLE 8
According to the Invention
One-part developer concentrate:
The following concentrate constituents were added to water in succession:
sodium hydroxide
30
g
optical brightener
10
g
sodium carbonate
100
g
DEHX solution
80
ml
triethanolamine
80
g
CD3
70
g
dimethylacetamide
120
g
EDTA
30
g
potash
30
g
made up to 1 liter with water.
The cation concentration (Na +
, K +
) amounted to 3.1 mol/l, of which 86 mol % was Na +
ions.
With a cation content corresponding to 86 mol % sodium, the concentrate formed 2 phases; both phases were completely dissolved and well separated from each other.
EXAMPLE 9
According to the Invention
The following concentrate constituents were added to water in succession:
sodium hydroxide
30
g
optical brightener
10
g
sodium carbonate
100
g
DEHX solution
80
ml
HADS
65
g
polyethlene glycol, mol wt. 400
80
ml
CD3
70
g
dimethylacetamide
120
g
EDTA
30
g
potash
30
g
made up to 1 liter with water.
The cation concentration (Na +
, K +
) amounted to 3.1 mol/l, of which 86 mol % was Na +
ions.
With a cation content corresponding to 86 mol % sodium, the concentrate formed 2 phases; both phases were completely dissolved and well separated from each other.
EXAMPLE 10
According to the Invention
The following concentrate constituents were added to water in succession:
sodium hydroxide
30
g
optical brightener
10
g
sodium carbonate
100
g
DEHX solution
80
ml
HADS
65
g
CD3
70
g
caprolactam
120
g
EDTA
30
g
potash
30
g
made up to 1 liter with water.
The cation concentration (Na +
, K +
) amounted to 3.1 mol/l, of which 86 mol % was Na +
ions.
With a cation content corresponding to 86 mol % sodium, the concentrate formed 2 phases; both phases were completely dissolved and well separated from each other
The one-part concentrates according to the invention were stable and resulted in a sensitometry corresponding to this type of product when employed for the processing of a colour paper under standard conditions.
EXAMPLE 11
The usual constituents of a colour developer regenerator were mixed together in a concentrate (the ready-to-use regenerator was prepared from the concentrate by dilution with water):
One-part, one-phase developer concentrate:
DEHX solution
35
ml
CD 3
50
g
diethylene glycol
30
ml
optical brightener
2
g
EDTA
10
g
potassium carbonate
60
g
pH adjusted with KOH to 13.5
made up to 1 liter with water.
Precipitation of ingredients occurs at 20° C.
EXAMPLE 12
Comparison
One-part, one-phase developer concentrate:
HADS
35
g
CD 3
50
g
diethylene glycol
30
ml
optical brightener
2
g
EDTA
10
g
potassium carbonate
60
g
pH adjusted with KOH to 13.5
made up to 1 liter with water.
Precipitation of ingredients occurs at 20° C.
EXAMPLE 13
According to the Invention
One-part, one-phase developer concentrate:
DEHX solution
35
ml
CD 3
50
g
diethylene glycol
30
ml
optical brightener
2
g
EDTA
10
g
sodium carbonate
60
g
pH adjusted to 13.5 with NaOH
made up to 1 liter with water.
No precipitation occurs at 20° C.
EXAMPLE 14
According to the Invention
One-part, one-phase developer concentrate:
HADS
35
g
CD3
50
g
diethylene glycol
30
ml
optical brightener
2
g
EDTA
10
g
sodium carbonate
60
g
pH adjusted to 13.5 with NaOH
made up to 1 liter with water.
No precipitation occurs at 20° C.
EXAMPLE 15
Comparison
One-part, one-phase developer concentrate:
potassium disulphite
40
g
CD4
60
g
hydroxylammonium sulphate
30
g
potassium carbonate
40
g
EDTA
20
g
potassium bromide
5
g
pH adjusted to 10.6 with KOH
made up to 1 liter with water.
Precipitation of ingredients occurs at 20° C.
EXAMPLE 16
Comparison
One-part, one-phase developer concentrate:
HADS
75
g
CD4
60
g
potassium carbonate
40
g
EDTA
20
g
potassium bromide
5
g
pH adjusted to 10.6 with KOH
made up to 1 liter with water.
Precipitation of ingredients occurs at 20° C.
EXAMPLE 17
According to the Invention
sodium disulphite
36
g
CD4
60
g
hydroxylammonium sulphate
30
g
sodium carbonate
31
g
EDTA
20
g
sodium bromide
4.3
g
pH adjusted to 10.6 with NaOH
made up to 1 liter with water.
No precipitation occurs at 20° C.
EXAMPLE 18
According to the Invention
One-part, one-phase developer concentrate:
HADS
75
g
CD4
60
g
sodium carbonate
31
g
EDTA
20
g
sodium bromide
4.3
g
pH adjusted to 10.6 with NaOH
made up to 1 liter with water.
No precipitation occurs at 20° C.
EXAMPLE 19
Comparison
One-part, two-phase developer concentrate:
HADS
75
g
CD4
60
g
caprolactame
160
g
potassium carbonate
40
g
EDTA
20
g
potassium bromide
5
g
pH adjusted to 10.6 with KOH
made up to 1 liter with water.
Precipitation of ingredients occurs at 20° C.
EXAMPLE 20
According to the Invention
One-part, two-phase developer concentrate:
HADS
75
g
CD4
60
g
caprolactame
160
g
sodium carbonate
31
g
EDTA
20
g
sodium bromide
4.3
g
pH adjusted to 10.6 with NaOH
made up to 1 liter with water.
No precipitation occurs at 20° C.
EXAMPLE 21
According to the Invention
One-part, two-phase developer concentrate:
HADS
75
g
CD4
60
g
polyethylene glycol, molecular weight 400
250
ml
sodium carbonate
31
g
EDTA
20
g
sodium bromide
4.3
g
pH adjusted to 10.6 with NaOH
made up to 1 liter with water.
No precipitation occurs at 20° C.
EXAMPLE 22
A colour photographic recording material was produced by depositing the following layers in the given sequence on a film base comprising paper coated on both sides with polyethylene. The quantitative data are given with respect to 1 m 2
2.5 mg small polymethyl methacrylate spheres with an average particle diameter of 0.8 μm
The colour photographic recording material was exposed though a step wedge. In the course of this procedure, additional filters were inserted into the beam path of the exposure device, so that the wedge appeared neutral at an optical density of D=0.6.
The material was processed under the following conditions:
Step
Time
Temperature
developing
27 seconds
39° C.
bleach-fixing
27 seconds
35° C.
stabilising
54 seconds
33° C.
First of all, the ready-to-use developers comprising the concentrates according to Example 5 and 13 were used as the colour developers, and then the ready-to-use developer prepared from three separate concentrates according to the prior art was used as the colour developer. Both ready-to-use developers were of the same composition.
Bleach Fixing Bath
ammonium thiosulphate solution, 58% by weight, aqueous
80
ml
sodium disulphite
5
g
ammonium iron EDTA, 48% by weight, aqueous
70
ml
made up to 1000 ml with water, pH adjusted to 6.5 with ammonia or acetic acid.
Stabilising Bath
water
900
ml
sodium sulphite
2
g
hydroxyethanediphosphonic acid, disodium salt
4
g
sodium benzoate
0.5
g
made up to 1000 ml with water, pH adjusted to 5 with sodium hydroxide solution or acetic acid.
Drying
The images produced were identical with regard to their sensitometric quality.
EXAMPLE 23
A colour photographic recording material for colour negative colour development was produced by depositing the following layers in the given sequence on a transparent film base of cellulose triacetate. The quantitative data are given with respect to 1 m 2
in each case. The corresponding amounts of AgNO 3
are quoted for silver halide deposition. The silver halides were stabilised with 1 mmol 4-hydroxy-6-methyl-1,3,3a,7-tetraazaindene per mol AgNO 3
. All the emulsions were chemically ripened, in the optimum manner, with sulphur, selenium and gold.
1st layer
(antihalo layer)
0.3
g
black colloidal silver
1.2
g
gelatine
0.3
g
UV absorber UV-2
0.2
g
DOP (developer oxidation product) scavenger SC-3
0.02
g
tricresyl phosphate (TCP)
2nd Layer
(low red-sensitivity layer)
0.7
g
AgNO 3
of an AgBrI emulsion which was spectrally
sensitised to red, comprising 4 mol % iodide, average
grain diameter 0.42 μm, AV 5, VVK 25%
1
g
gelatine
0.35
g
colourless coupler C-1
0.05
g
coloured coupler RC-1
0.03
g
coloured coupler YC-1
0.36
g
TCP
3rd Layer
(medium red-sensitivity layer)
0.8
g
AgNO 3
of an AgBrI emulsion which was spectrally
sensitised to red, comprising 5 mol % iodide, average
grain diameter 0.53 μm, AV 6, VVK 23%
0.6
g
gelatine
0.15
g
colourless coupler C-2
0.03
g
coloured coupler RC-1
0.02
g
DIR coupler D-1
0.18
g
TCP
4th Layer
(high red-sensitivity layer)
1
g
AgNO 3
of an AgBrI emulsion which was spectrally
sensitised to red, comprising 6 mol % iodide, average
grain diameter 0.85 μm, AV 9, VVK20%
1
g
gelatine
0.1
g
colourless coupler C-2
0.005
g
DIR coupler D-2
0.11
g
TCP
5th Layer
(intermediate layer)
0.8
g
gelatine
0.07
g
DOP scavenger SC-2
0.06
g
aluminium salt of aurintricarboxylic acid
6th Layer
(low green-sensitivity layer)
0.7
g
AgNO 3
of an AgBrI emulsion which was
spectrally sensitised to green, comprising 4 mol %
iodide, average grain diameter 0.35 μm, AV 5,
VVK 20%
0.8
g
gelatine
0.22
g
colourless coupler M-1
0.065
g
coloured coupler YM-1
0.02
g
DIR coupler D-3
0.2
g
TCP
7th Layer
(medium green-sensitivity layer)
0.9
g
AgNO 3
of an AgBrI emulsion which was spectrally
sensitised to green, comprising 4 mol % iodide, average
grain diameter 0.50 μm, AV 7, VVK 24%
1
g
gelatine
0.16
g
colourless coupler M-1
0.04
g
coloured coupler YM-1
0.015
g
DIR coupler D-4
0.14
g
TCP
8th Layer
(high green-sensitivity layer)
0.6
g
AgNO 3
of an AgBrI emulsion which was
spectrally sensitised to green, comprising 6 mol %
iodide, average grain diameter 0.70 μm, AV 10,
VVK 20%
1.1
g
gelatine
0.05
g
colourless coupler M-2
0.01
g
coloured coupler YM-2
0.02
g
DIR coupler D-5
0.08
g
TCP
9th Layer
(yellow filter layer)
0.09
g
yellow dye GF-I
1
g
gelatine
0.08
g
DOP scavenger SC-2
0.26
g
TCP
10th Layer
(low blue-sensitivity layer)
0.3
g
AgNO 3
of an AgBrI emulsion which was
spectrally sensitised to blue, comprising 6 mol % iodide,
average grain diameter 0.44 μm, AV 4, VVK 20%
0.5
g
AgNO 3
of an AgBrI emulsion which was spectrally
sensitised to blue, comprising 6 mol % iodide, average
grain diameter 0.5 μm, AV 5, VVK 18%
1.9
g
gelatine
1.1
g
colourless coupler Y-1
0.037
g
DIR coupler D-6
0.6
g
TCP
11th Layer
(high blue-sensitivity layer)
0.6
g
AgNO 3
of an AgBrI emulsion which was spectrally
sensitised to blue, comprising 7 mol % iodide, average
grain diameter 0.95 μm
1.2
g
gelatine
0.1
g
colourless coupler Y-1
0.006
g
DIR coupler D-7
0.11
g
TCP
12th Layer
(micrate layer)
0.1
g
AgNO 3
of a micrate-AgBrI emulsion, comprising 0.5
mol % iodide, average grain diameter 0.06 μm
1
g
gelatine
0.004
mg
K 2
[PdCl 4
]
0.4
g
UV absorber UV-3
0.3
g
TCP
13th Layer
(Protective and hardener layer)
0.25
g
gelatine
0.75
g
hardener HM
The overall layer structure exhibited a swelling factor 3.5 after hardening.
Substances used in Example 23 which are not described in Example 22:
After exposure through a neutral wedge filter, development was effected according to The British Journal of Photography, 1974, pages 597 and 598. In the course of this procedure, a developer solution was first of all used which was prepared from the one-part concentrate according to Example 17 and secondly a developer solution was used which was prepared from three separate concentrates according to the prior art.
The colour negatives obtained were identical as regards their sensitometric quality.
Claims
1. A one-part color developer concentrate which comprises at least two phases and which is free from precipitates at 20° C., which contains at least one color developer substance, at least one antioxidant, at least one anti-lime agent, a buffer system and alkali has a pH of at least 9 and a concentration of cations from 0.5 to 15 mol/l, wherein at least 10 mol % of the cations are sodium ions and contains at least 50 mmol color developer substance per liter.
2. A one-part color developer concentrate according to claim 1, wherein the sodium ion content is at least 30 mol %.
3. A one-part color developer concentrate according to claim 1, wherein the sodium ion content is at least 50 mol %.
4. A one-part color developer concentrate according to claim 1, wherein the organic solvent is caprolactam.
5. A one-part color developer concentrate according to claim 1, wherein the color developer substance is 4-(N-ethyl-N-2-methylsulphonylaminoethyl)-2-methyl-phenylenediamine sequisulphate or 4-(N-ethyl-N-2-hydroxyethyl)-2-methyl-phenylenediamine sulfate.
6. A one-part color developer concentrate according to claim 1, wherein at least one of the phases is an organic phase and one is an aqueous phase, the organic phase containing one or more water-soluble organic solvents, wherein 50 to 95% by weight of the sum of organic solvents and water are water.
7. The one-part color developer concentrate as claimed in claim 6, wherein 60 to 90% by weight of the sum of organic solvents and water are water.
8. The one-part color developer concentrate as claimed in claim 6, wherein said water-soluble solvents are urea, alcohols, ketones, carboxylic acid esters, phosphonic acid esters, aldehydes, oximes or amines.