DE1924723A1 - Color bleaching preparation for the photographic silver color bleaching process - Google Patents

Description

CIBA AKTIENGESELLSCHAFT, BASEL (SWITZERLAND)

Case TEL 54 / e

Dr. F. To the $ l # in - Dr. E. Ajsmann

Dr R. Koenigsberger Dipl. Fhy $. R. Holzbau "

Polenlanwälf MOndtsn 2, BrauhauMtrafj · 4 / IH

Dye bleaching preparation for the photographic silver dye bleaching process.

The present invention relates to color bleaching preparations for the treatment of photographic material by the silver dye bleaching process. Preferably lie these color blending preparations in the form of baths.

909882/1542

The well-known dye bleach baths for this process Generally consist of an acid such as Hydrochloric acid *, a complexing agent such as thiourea and optionally a color bleaching catalyst such as 2,3-diaminophenazine.

Among the disadvantages of the baths used so far It is particularly important to emphasize that it is especially at higher levels Temperatures have a very corrosive effect «that they too when not in use due to oxidation or hydrolysis Constituents change greatly and that they are reaction products such as, for example, dissolve silver salts from the photographic materials to be treated, which gives them their activity change and are difficult to regenerate in continuous operation.

It is therefore an aim of the present invention » To create a dye bleach bath «which has the above disadvantages does not own.

Earlier it was suggested "Bitich baths Add iodides as complexing agents (compare britiaohe Patent 535Ϊ30, corresponds to U.S. Patent specification

2 217 544, and DAS 1 156 36öJ but are those with these

-. ■■ - = ■ '■. - '"■■■■ ■ ι results obtained in baths cannot be reproduced« since the baths are exhausted after only a short period of use or short-term storage.

It has now been found that “bleaching agents which contain an acid are“ a water-soluble iodide ”. Reductone

909882/1542

ORIGINAL INSPECTED

and optionally, contain a dye bleach analyzer, do not have the disadvantages mentioned.

The present invention is accordingly a dye bleaching preparation for the photographic silver dye bleaching process, which contains an acid, a water-soluble iodide and optionally a color bleaching catalyst, characterized in that this preparation is additionally still contains a reductone.

The advantages of the dye bleaching preparation according to the invention become particularly evident when the preparation is in continuous operation and at increased rates Temperature, is used.

Suitable acids are, for example, sodium hydrogen sulfate, Sulphamic acid, acetic acid, citric acid, organic sulphonic acids or especially strong acids such as hydrochloric or Sulfuric acid.

The water-soluble iodide can be, for example, potassium iodide, sodium iodide, ammonium iodide or hydriodic acid. ...- "The color bleaching catalyst can either be in the color bleaching preparation dissolved or contained in the photographic material to be bleached and can, for example, be a Be pyrazine, a quinoxaline, or a phenazine.

Among the reductones, the aci-reductones are preferred. The aci-reductones preferably correspond to the tautomeric ones Formulas

909882 / '..1.5.4 2. ■,: ■■■;

O
Il
σ— OH
ϊ
-CH -> OH
σ-— 1324723 R ^ -CH
\ ι "■; ■
X
κ R-CH
V.
0 OH
—Σ X

wherein X is one of the groups JlC = O, JCi = NH or ^ CH-COOH, R is an optionally substituted aryl radical or a radical of the formula R ₁ -CHp (CH-OH) ,, where η is an integer from 1 to 4 and R., if n = 2 to 4, a hydrogen atom or a hydroxyl group and, if n = 1, a hydroxyl group. .

Particularly suitable aci-reductones are also cyclic or acyclic compounds, which are a 3-carbonyl-enediol- (l, 2) - Grouping the formula

OH OH 0

ι ι n. ■ "■ -" · - ·

contain*

Suitable reductones are, for example, reductic acid, Triose reductone 3-hydroxy-5-pheny! Tetronic acid, 3-hydroxy-5-phenyltetronimide, 5-o-chlorophenyl -3-hydroxytetronimide, Isoascorbic acid and preferably ascorbic acid, or mixtures of these reductones.

The reductone to be used is expediently chosen so that that the normal potential of reductone / dehydroreductone in the selected conditions is more negative than the normal

909882 / 15A2

ir ■ "'■'

potential iodine / iodide. Let the effective potentials

's-

also vary by changing the proportions.

At pH = 1, the following normal potentials become measured against a normal hydrogen electrode:

J ₂ / 2J ~ +. 536 mV

Ascorbic acid / dehydroaseorbic acid + 330 , Reductic acid / dehydroreductic acid. +420 mV Triose reducton / dehydrated triose reducton * 220 mV.

In other words, it means the parbone bleaching preparation. contain a reductone at pH 1 should, which ^ -a normal potential reductone / dehydroreductone of less than 500 mV.

Since the potential J "/ 2. J" is Pjj-independent, the potential, reductone / dehydrocompound, however, becomes more positive, so that in strongly acidic baths there must be more reductone than in weak acidic baths, it is generally sufficient to use 1 to 10 mol percent of reductone, based on the amount of iodide present, especially with reductones whose potential, as with the above-mentioned reductones themselves, / with: iß- = 0 always is even more negative than de & Jods «;.

The color brittle preparation can be used as a bath ζ.Β » also as a present thickening - in the form of a cplloidal Mass or photographic layer.

i.

Appropriate technical measures> such as applying protective layers or encapsulating the active components, the color bleaching preparations can ^{: so} in a photographic

909882/1 5 / i2 -.

'Material are brought so that the color bleaching effect can only develop when the photographic material is processed. In special cases, mixtures of iodides and reductones can also be present while . Acid and pale bleach catalyst are housed in a different phase (see, for example, French patent specification 1 50 '^ 238).

In the case of the well-known iodide-containing baths that do not contain any reductone, more or less reproducible results can only be achieved if one works with complete exclusion of air. In the air, however, such a bath quickly becomes dark, has a corrosive effect and loses its bleaching power, so that the color images obtained become flatter and flatter and ultimately cannot be completely bleached at all. Baths containing reductone, on the other hand, can even be stirred with air and always give constant results over a long period of time.

In the use of the inventive dye bleach composition for bleaching Obergurig reducible image substances such as azo dyes, nitro dyes and diazonium salts in the presence of metallic images, these metallic ß images can opposite (negative) in a known manner, the template or the template the same direction (positive). It is advisable to remove any metal salts that may still be present, such as silver chloride or silver bromide, from the material after developing and before bleaching the color

909882/1542

(to be fixed), as otherwise the iodide content of the dye bleaching bath would quickly be exhausted and larger amounts of poorly soluble silver iodide would be formed. After the parbene bleaching , the remaining silver is removed in a known manner. _s

In addition to the components mentioned, the parb bleaching baths can contain conventional additives such as complexing agents, wetting agents and solvents .

In the examples below, percentages are percentages by weight.

909882/1542

example 1

One only with the dye of the formula

(3)

colored silver bromide emulsion is made in the usual manner Poured onto a film substrate, behind a step wedge exposed and processed as follows at 24 ° Cϊ 1, development, 6 minutes * ·;

. 2g p-methylaminophenol sulfate

50 g sodium sulfite anhydrous ,., 6 g hydroquinone

20 g sodium carbonate anhydrous 2 g potassium bromide

1 liter of water *

2nd stop bath, 1 minute

10 g of sodium acetate crystallized from 20 g of glacial acetic acid

1 liter of water.

3 »Fixation, 4 minutes 20% solution of nutrient thiosulphate

4th watering, 10 minutes - ^{Vr :} ' ^: - ^{; £::}

5. Color bleaching, 8 minutes

500 ml water 27 ml sulfuric acid (96 #) 0.2 g ascorbic acid

909882/1542

20 ml of a mixture

Benzyl alcohol. Diethylene glycol Water (2Ö #)

10 mg 6-benzoylamino-2,3-dimethyl-quinoxaline

10 g potassium iodide

1 liter of water

6. Soak, 4 minutes

7. Silver bleaching, 6 minutes

500 ml of water 27 ml / sulfuric acid 20 g of copper sulfate crystallized 60 g potassium bromide

1 liter of water

8. Soak for Λ minutes

9 fixation, 4 minutes 20 # solution of sodium thio-

sulfate.

10. Soak, 10 minutes "

11. Drying. . ·

In this way, you get something that runs in the same direction as the original (positive) color image, the gradation of which is shown in curve 1 will. It can be seen from this curve, that the dye can be completely bleached.

If you let the dye bleach bath (5) of the above composition stand for four days in an open vessel and then repeat the process as above, so an .identical bleaching, which also corresponds to curve 1, is obtained.

If you use a dye bleach bath (5) which does not contain ascorbic acid, you get different ones depending on the age

909 882/15 42

- OK -

of the bath dependent results. In the freshly made bath one obtains a bleaching that corresponds to the color gradation curve coincides. Because this curve is difficult to reproduce it is not separately applied to the curve board been. If the bath is left to stand for 4 days without ascorbic acid> and then using it for bleaching, you get that of the Curve 2 corresponding gradation. You can see from the curve that a complete pale bleaching can no longer be achieved can.

909882/1542

-. ■. ■ - ■■■■■ .- ■ ': -.'-: · "- -Example 2 _: - ... ...

The procedure is as in Example 1, but a Dye bleach bath, which instead of ascorbic acid 1 g / l Triose-Redukton contains «The Triose-Redukton is obtained, by Bian lead reductonate (after Euler-Eistert, Chemie and Biochemistry of Redufctone and Reduktonatey Verlag Snfce, Stuttgart 1957 »page 53) is reacted with sulfuric acid and separated from the lead sulfate formed.

Using the dye bleaching bath immediately gives the same results as using it after four days Stand in the air.

It can be seen from the gradation curves 3 and 4 that similar results as in Example 1 can be obtained.

909882/1542

- IS-

Examples 3, 4, 5, β

The procedure is as in Example 1, but used Color lead baths of the following composition.

{Example 3) (Example 4) (Example <·>) (Example 6)

60 S. Sulfamic acid 1 G Iso-ascorbic acid 1 G 3-hydroxy «5-phenyl tetronic acid

or 1 g

or 1 g

10
17th

mg
G

3-hydroxy-5-phenyl tetronimide

5-o-chlorophenyl-3-hydroxy-tetronimide

Phenazine potassium iodide water to 1 liter *.

If you use the dye bleaching baths immediately, you will get the same results as when used after stinging for four days in the air.

If the dye bleach bath without reductone is used after 4 days If color bleaching is used, it is a complete bleaching of the dye is no longer possible, as shown in curves 5 and 6 can be seen.

909882 / 1S42

Example J "

The procedure is as in Example 1, but the following dye bleach bath is used:

60 g p-toluenesulfonic acid

1 g ascorbic acid 10 mg phenazine 15 g ammonium iodide

1 liter of water

From the gradation curves 7 and 8 it can be seen that similar results as in Example 1 can be obtained.

Example 8

The procedure is as in Example 1, but used the following color bleach bath:.

- 60 g of sulfamic acid

1 g ascorbic acid 50 mg 2,5-dimethylpyrazine '' 17 "g potassium iodide ■

1 liter of water - ■ -..- ■

From the gradation curves 9 and 10 it can be seen that that similar results as in Example 1 are obtained.

909 882/15

Example 9

The procedure is as in Example 1, but treated for 12 minutes in a dye bleach bath with the following composition: -

5 g sodium acetate
10 ml glacial acetic acid

1 g of ascorbic acid

200 mg 2 _J 3-dimethyl-6-methoxyehinoxaline 160 g potassium iodide

1 liter of water

Using the dye-bleaching bath immediately gives the same result as using it after standing in the air for four days. The dye is completely bleached behind the lightest wedge step. If the Farbbleichbad without ascorbic acid recognized as the solution-dependent results obtained from different age * ^c. After standing in the air for four days, the dye can no longer be completely bleached. A similar result is obtained if, instead of the acetic acid-acetate combination, a .... \ citric acid-citrate combination is used · -ΐ

009882/1542

Example 10 '

A photographic material with three parb layers contains a gelatin layer with the color bleaching catalyst 2,3-diphenyl-6-aminoquinoxaline on a base, and over it a red-sensitive silver bromide emulsion with the blue-green dye of the formula

OH

HO ₃ S

ΰχ «

OH ₃ O

HO

SO ₃ H

OCH

HO ₃ S

on top of it a green-sensitive silver bromide emulsion with the purple dye of the formula:

. ι

-NH

HO ₃ S

HO ₃ S

H ₂ N

N = N-SO ₃ H

909882 / 15A2

This is followed by a layer of silver bromide with the yellow dye of the formula ί

H "C0 ³

1 T

The color layers are separated by gelatine layers. '

This copy material is behind a step wedge ' exposed and processed according to Example 1. For farto bleaching however, the following bath is used;

27 ml sulfuric acid ($ 96) ^ 0.5 g ascorbic acid
25 g potassium iodide

Water to 1 Xdter

In this way you get a positive image of the Step wedge, with all three behind the brightest wedge step Dyes are completely bleached. The same result is obtained one when this dye bleach bath after four days of standing is used.

However, if the lead dye bath is used "without heductone after yier days for lead dye, it is no longer possible to bleach the three dyes to white *

909882/1542

Legend for the color gradation curves 1 to 10

D = color density

Log E = logarithm of exposure

example 1

Curve 1: color lead chbaC. with ascorbic acid, fresh and Dye bleach bath with ascorbic acid, 4 days old

Curve 2: dye bleach bath without ascorbic acid, 4 days old

Examples
until 6

Curve 3 '· dye bleach bath with triose reductone, fresh and dye bleach bath with triose reductone, 4 days old

Curve 4 '· dye bleach bath without triose reductone, 4 days old

Curve 5 '· Dye bleach bath with reductone, fresh, and dye bleach bath with reductone, 4 days old

Curve 6: dye bleach bath without reductone, 4 days old

909882/154

Example 7 \

Curve 7 · dye bleach bath with ascorbic acid, fresh and dye bleach bath with ascorbic acid, 4 days old

Curve 8: dye bleach bath without ascorbic acid, 4 days old

Example 8

Curve 9 ί color bleach bath with ascorbic acid, fresh and Dye bleach bath with ascorbic acid, 4 days old

Curve 10: dye bleach bath without ascorbic acid, 4 days old,

909882/1

Claims (16)

Claims 1. Color bleaching for the phot © graphic silver color bleaching process, which contains an acid, a water-soluble iodide and optionally a color bleach catalyst, characterized in that this preparation also contains a reductone. 2. dye bleaching preparation according to claim 1, characterized in that this preparation is an aci- 'as a reductone Contains reductone. 3 · colored lead preparation according to claim 2, characterized in that this preparation is an aci-reductone of the tautomeric formulas 0 OH 1 ! C CH I I ν R- <JH -X • ^ contains, where X is one of the groups O = K), C = HH or GH-CGOH, 909882/1542 R is an optionally substituted aryl radical or a radical of the formula R ₁ -CHp- (CHOH) ,, where η is a positive integer from 1 to 4 and R ,, if η = 2 to 4, a hydrogen atom or a hydroxyl group and, if η = 1, denote a hydroxyl group. . 4. Color bleaching preparation according to claim 2, characterized in that this preparation contains an aci-reductone which is a cyclic or acyclic compound which has a 3-carbonyl-enediol (1,2) grouping represents. 5 · Parb bleaching preparation according to one of Claims 1 to 4, characterized in that this preparation is a reductone with a normal potential of reductone / dehydroreductone, which is more negative than the normal iodine / iodide potential contains. 6. color bleaching preparation according to any one of claims 1 to 5, characterized in that this preparation is called a reductone Reductic acid, triose reductone or preferably Contains ascorbic acid. 7. color bleaching preparation according to any one of claims 1 to 5, characterized in that this preparation is iso-ascorbic acid, 3-hydroxy-5-phenyltetronic acid, 3-hydroxy-5-phenyl-tetronimide or 5-o-chlorophenyl-3-hydroxy- 909882/1542 Contains tetronimide. 8. Farbblkichzubereituhg according to any one of claims 1 to 6, characterized in that "that this preparation is in the In the form of a dye bleach bath. 9. color bleaching preparation according to claim 1, characterized in that that this preparation as an acid is a strong acid contains. 10. color bleaching preparation according to claim 8, characterized in that that this preparation as a strong acid, an organic sulfonic acid sodium hydrosulfate. or in particular Contains hydrochloric or sulfuric acid. 11. color bleaching preparation according to claim 8, characterized in that ' that this preparation contains acetic acid or citric acid as acid. 12. color bleaching preparation according to claim 1, characterized in that, indicates that this preparation is available as a water-soluble iodide, hydriodic acid, ammonium iodide, sodium iodide or preferably contains potassium iodide. 909882/15 42 13 · Dye bleaching preparation according to claim 1 _s, characterized in that this preparation contains a pyrazine, quinoxaline or phenazine as the dye bleaching caustic agent. , 14. Process for the production of color photographic Images according to the silver color bleaching process, characterized in that the color bleaching is carried out in a color bleaching preparation which has a composition according to any one of claims 1 to 11 is carried out. 15. Use of the color bleaching preparations according to a of claims 1 to 11 for color bleaching in a process for producing color photographic images according to Silver dye bleaching process. 16. Those obtainable by the method in claim 12 color photographic images. 909882/1542