DE1091429B - Process for the formation of color photographic images by the silver dye bleaching process - Google Patents

Description

The invention relates to a method for producing color photographic images the silver dye bleaching process.

The so-called silver color bleaching process has long been known for producing photographic images consisting of several colored partial images. In this case, the individual color partial images are first created as silver images in layers, which are either already homogeneously colored with dye or are homogeneously colored after the silver images have been produced. The dyes are then locally bleached in a color bleaching process depending on the associated silver partial image, the dye being destroyed at the image areas where silver is located. In the production of multicolored pictures, in particular the commonly used three-color or four-color pictures, the bleaching process takes place in several different colored layers or media. For the purpose of color matching, it is desirable to be able to adapt the gradation of the partial images assigned to the individual colors to one another. The need for such an adjustment arises from the variety of variables given by the dyes used, the original silver emulsions and intermediate process steps. In principle, there is a possibility of influencing this comparison by selecting the appropriate gradation of the silver images present before the color bleaching process. The addition of substances which accelerate or retard the bleaching rate of the dyes is also known. In spite of all these proposals, however, a satisfactory adjustment of the multicolor material causes considerable difficulties, and such adjustment is again endangered or even made impossible by inevitable fluctuations in the production and treatment of the material.

According to the invention there is provided a method for the generation of at least two colored partial images photographic images applied by the silver dye bleaching process, which is characterized is that for bleaching the various partial images at least two successive color bleaching baths are used, their composition in particular with regard to the content and type of catalysts and / or the silver complexing agent is varied in such a way that it affects the dyes of the various partial images have different bleaching effects.

Advantageously, the second dye bleach bath essentially only bleaches the dyes of the remaining ones partial images not bleached from the first bath. There are also other combinations of the successive effects Dye bleach baths conceivable. So, for example, the first dye bleach bath on the dyes of all Partial images have an image-wise bleaching effect during the process of generation

of colored photographic images

after the silver dye bleaching process

Applicant:
CIBA Aktiengesellschaft, Basel (Switzerland)

Representative: Dr.-Ing. F. Wuesthoff,

Dipl.-Chem. Dr. rer. nat. E. Frhr. v. Bad luck

and Dipl.-Ing. G. Puls, patent attorneys,

Munich 9, Schweigerstr. 2

Claimed priority:
Switzerland from June 3, 1958 and April 16, 1959

Dr. Paul Dreyfuss, Basel (Switzerland),
has been named as the inventor

The second dye-bleach bath essentially only bleaches the dyes of a partial image, or the second dye-bleach bath can be used have an image-wise bleaching effect on the dyes of all partial images, while the first dye-bleaching bath im essentially only the dyes of a partial image are bleached. Through the use of such consecutive Dye bleaching baths, each due to their different content of catalysts or silver complexing agents have a bleaching effect on the dyes of the various partial images of the material difference, This results in a considerably greater possibility of variation for the implementation of the now separately from one another taking place bleaching operations. There is now the possibility of the fading processes in the individual To guide layers independently of one another so that a desired result is achieved, for example i.e. the comparison of the color gradation of a three-color image on a neutral gray scale. This can Matching either initially determined empirically by testing for a specific material and then at the later practical application can be carried out unchanged in the specified form. But it is it is also possible to adapt this comparison again and again individually to the image currently being treated by for example the second dye-bleach bath, taking into account those obtained in the first dye-bleach bath

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Partial images, is influenced in such a way that the desired off- generally used dyes are achieved in the bleaching equilibrium. bad not bleached in an identical way. So, for example,

To carry out the process according to the invention, a dye made from a poorly bleaching material is used one is advantageously sufficiently bleached in the image standing on top of one another, so becomes following baths substances, which on the fading 5 at the same time with the more easily bleaching dyes one or some of the pictures in the various layers are too steep due to excessive bleaching The dyes used have a different effect. When using a single bleach bath exercise. This can be done, for example, by changing the degree of bleaching only for all layers regulate successive use of one acidic and one together. The procedure with only one alkaline bleach, e.g. B. alkaline stannite solution. io bleach bath fails as soon as material contains more than However, one preferably achieves such a different, one layer, e.g. B. with the three common today accelerating or retarding effect, different colored layers, is used as a by having at least one for bleaching a selective tuning of the bleaching process in the or several dyes serving bath a fabric individual layers z. B. by simple change adds, which one the bleaching of this or these 15 the duration of the bleach bath is not possible. By Dyes assigned to partial color images accelerate the possibility of compensating for the present invention and / or at the same time there is at least one bleaching process in the various layers another color sub-image assigned dye of fundamental importance for the color balance and has a delaying or preventing effect. As for the quality of the picture.

Substances that act as selective bleach catalysts in this way, 20 The invention does not only apply to the whole

are to be named for example riboflavin (lactoflavin), process, but also on partial steps of this process

Lumazine (2,6'-dioxotetrahydro- [pyrimidino-4 ', 5': 2,3-pyrene. For example, the multicolor material

razin]), alloxazine, amidol and 2,3-aminooxyphenazine. in each of the successive dye bleach baths like this

These fabrics and their production are, among other things, long bleached until at least one of the color

described in British patents 651 124 25 substances is bleached to the end, so until at any point in the image

or 657 374. Other substances suitable as catalysts silver and dye are still present at the same time,

are known from the patent literature, for example the treatment in the individual bleaching baths

British Patent 490 451. Also influenced but also canceled at an earlier point in time

the content of complexing agents in the bleach bath, if none or only some of the

For example, on potassium bromide or thiourea the 30 appropriate bleaching bath bleachable dyes come to an end

Bleaching process of different dyes are bleached in different ways, or it can be used for some dyes.

Dimensions. Also mild oxidizing agents, tartrazine, nitro- timely canceled and for the other dyes too

benzenesulfonic acid, etc., such as. B. in the British patent end, with the order of the baths

Fonts 539 190, 539 391 and 539 509 as additions to any can be.

Bleach bath described act in the specified 35 The invention also extends to the use

Senses. of substances in dye-bleaching baths which bleach the

Another advantage of the process according to the invention is to partially delay or partially accelerate different dyes by dividing them into two successive baths. If necessary, however, one can be that between the two color bleaching such selective bleaching of the different color baths one or more other baths 40 layers can also be inserted by setting certain conditions, which in turn are used in the baths, such. B. temperature value p _H, etc., act on one or some of the partial images. This can be done. The successive bleach baths are made possible by the fact that after the first one can be alkaline or acidic, or one can be alkaline color bleaching bath some partial images, namely those in the first and one can be acidic. The photographic material bath bleached partial images, as color images or as 45 can be recording or copying material, reflective image or color images and silver images, the remaining, namely the transparent image, cinema film or material for momentarily unbleached partial images, however, can only be photographic as silver images; it can be separate layers or exist. So you can now contain one or more mixed grain emulsions.

Switch on method steps which either only apply. The invention will now be based on a few examples

the silver images, especially those not yet explained about the dye 50,

bleaching used silver images. Example 1
for example, between the first and second

A three-layer film consists of a red-sensitive one

and thus the gradation of the layer only in the following layer, which is coated with a dye according to Schulz, Farb-

second color bleaching bath resulting color images selectively 55 substance tables, 7th edition, II, pp. 220 to 222 - E. 1.142

influence. Depending on the type of attenuator used (C. I. Direct Green 27), one is colored on it

and its action on the different parts of the green-sensitive layer, with a dye

("Foot", linear part, "shoulder") of the characteristic according to Schulz, color tables, 7th edition, II, p. 48 -

The curve of the remaining silver images can be found in E. I. 79 (C. I. Acid Red 131), colored and finally

in different ways on the gradation of the then im 60 an unsensitized layer, the one with a yellow

The color images obtained in the subsequent bleach bath are colored by tetrazotization

act and thus the necessary for a good technical reproduction of benzidine-2,2'-disulfonic acid and coupling with

The agreement of the color gradation of the colored 1-phenyl-3-methylpyrazolone- (5) is obtained. All three

Largely achieve the image. Dyes are in the emulsion with an organic

The essential point of the invention lies in the fact that 65 base is precipitated so that it is non-diffusible; the base was after the

several successive dye bleach baths to United States Patent 2,317,184, Example 2, obtained. That

turn, whereby in each color bleaching bath only material was next to each other behind a step wedge

a part of the colored pictures is treated. exposed to blue, green and red light,

The advantages of the present invention over the wraps and fixes. This resulted in three silver so far known procedures are obvious. The 70 pictures, one each in the yellow, purple and blue

green layer. The bleach baths given below were used for bleaching, then the Excess silver is oxidized in a ferricyanide bath and eliminated in a fixing bath. Before the bleaching was cured in a formaldehyde bath and thorough watering was carried out between all baths.

Bleach baths

A. 100 g KBr,

100 ecm HCl, cone, pure,
Water to 11.

B. 10OgKBr,

100 ecm HCl, cone, pure,
0.05 g riboflavin,
Water to 11.

C. 100 g KBr,

100 ecm HCl, cone, pure,

Alloxazine saturated (less than 0.05 g), water to 11.

D. 50 g thiourea,
100 ecm HCl, cone, pure,
Water to 11.

E. 10OgKBr,

100 ecm HCl, cone,
20 g hydroquinone,
Water to 11.

F. 100 g KBr,

100 ecm HCl, cone.,
20 g amidol,
Water to 11.

The bleaching results are shown in the table below. Thereby means

- = no bleaching
+ = Traces of bleaching
+ + = weak bleaching
+ + + = medium bleaching
+ + + + = severe bleaching

of the respective layer

bath

A; B I C I D j E I F

Duration 90 minutes | 60 minutes 10 minutes 20 minutes 30 minutes 30 minutes

Yellow ....
Purple ..
Blue green

It has an accelerating effect on riboflavin or amidol compared to the additive-free bath A for blue-green, for Yellow slightly retarded. This is even more true for alloxazine, which additionally reduces the bleaching of Delayed purple. In contrast, thiourea or hydroquinone has an accelerating effect on yellow and purple.

Example 2

The starting material used in Example 1 was treated in baths A, B and C given in Example 1 for a period of 60 minutes at 20 ^{° C.} The purple image in baths A and B showed approximately the same degree of bleaching, and in bath C the bleaching was considerably reduced. The alloxazine present in bath C thus acts as a negative catalyst for the purple layer and as a positive catalyst for the blue-green layer.

Example 3

The starting material used in Example 1 was first in bath D for 15 minutes, then subsequently Treated 3 minutes in bath C, whereby a satisfactory agreement of the color gradations in the three layers was obtained.

Example 4

The starting material used in Example 1 was bleached for 20 minutes in bath E, followed by 5 minutes treated in Farmer's reducer and finally bleached in bath F for 15 minutes. It turned out to be a very good one Adjustment of the three color gradations obtained.

Example 5

The starting material described in Example 1 was exposed, developed and in the manner indicated there fixed. The material treated in this way was then first

40

60 5 minutes in the following bleach bath H and then 50 minutes in the bleach bath J treated.

H. 100 g potassium bromide,
100 ecm hydrochloric acid, cone,

2 mg 2,3-aminooxyphenazine,
Water to 11.

J. 100 g potassium bromide,
50 g thiourea,
100 ecm hydrochloric acid, cone,
Water to 11.

The silver still present in the material was then removed in the manner indicated in Example 1. By doing The colored material obtained in this way has all three color partial images which are superimposed in the required manner adjusted gradations.

The same satisfactory result was obtained when the developed material was first immersed for 30 minutes Bath J and then treated in Bath H for 10 minutes.

As a counter-test, the same material developed in the same way was used exclusively in one Composition bleach bath

G. 100 g potassium bromide,
50 g thiourea,
100 ecm hydrochloric acid, cone,

2 mg 2,3-aminooxyphenazine,
Water to 11

treated. It turned out that it was not possible even when using bleaching times of different lengths to obtain matching color gradations. Rather, the gradation of the cyan image was always steeper than that of the purple and yellow picture. An exclusive bleaching in bath H or Bad J, no satisfactory result can be obtained. When bleaching in bath H, the gradations were The purple and yellow image is too flat, the gradation of the

Cyan image too steep. When bleaching bath J was used, the gradation of the cyan image was opposite to that the purple and yellow image too flat.

Example 6

The starting material used according to Example 1 was initially bleached in bath J for 30 minutes. In This bath creates the yellow and purple picture and at the same time becomes a relatively large part of the picture silver removed so that with some practice the image can be seen visually (or possibly also by densitometric measurement) can be judged on its color balance. So the subsequent bleaching in the bath H can be repeated Check to be continued until the desired degree of bleaching of the cyan image is obtained. The picture is then completed by removing the remaining silver.

Claims (8)

PATENT CLAIMS: 1. A method for producing photographic images consisting of at least two colored partial images by the silver color bleaching process, characterized in that at least two successive color bleaching baths are used for bleaching the various partial images, the composition of which in particular with regard to the content and type of the catalysts and / or the silver complexing agents is varied in such a way that they have different bleaching effects on the dyes of the various partial images. 2. The method according to claim 1, characterized in that between the two bleaching baths at least one process step is switched on, which only applies to the not yet bleached silver images acts. 3. The method according to claim 1, characterized in that one of the baths riboflavin (lactoflavin) is added. 4. The method according to claim 1, characterized in that that Lumazin is added to one of the baths. 5. The method according to claim 1, characterized in that added alloxazine to one of the baths will. 6. The method according to claim 1, characterized in that amidol is added to one of the baths will. 7. The method according to claim 1, characterized in that hydroquinone is added to one of the baths will. 8. The method according to claim 1, characterized in that one of the baths 2,3-aminooxyphenazine is added. © 009 628/356 10.60