DE2036918A1 - Process for producing a photographic color image by the silver color bleaching process - Google Patents

Description

CIBA AKTIENGESELLSCHAFT, BASEL (SWITZERLAND)

Case TEL 68 / E Dr. P. Zuinrteln «w. - Dr. i. Α «« · »»

Dr.R.Ko «nIgeb * rg # r - Dipl. Phys. R. HobbauW

Dr. P. Zumatein Jun. Patent attorney

I Monchen 2, Irauhoiiutroe · 4 / iM

Process for the production of a photographic color image by the silver dye bleaching process, %

A common material for the silver dye bleaching process contains on a transparent or reflective Carrier a red-sensitive stained with cyan dye

009886/1631

ORIGINAL INSPECTED

Emulsion layer, over it a green sensitive with purple dye colored emulsion layer, and on top a blue-sensitive emulsion layer colored with yellow dye. Between these emulsion layers can there are also filter layers and other intermediate layers. Such a material is exposed, developed and finally processed into a color image * by looking at the available image dyes depending on of the developed metallic silver bleaches and the excess Silver halide and metallic silver removed from the material »

The known materials and those performed with them Processes have various disadvantages, which up to now could not be completely overcome *

If only as much silver halide is used in the photographic material as is required for the bleaching of the dye, the result is a material which is completely insufficiently light-sensitive. A large excess of silver halide is generally used, a large excess of silver is produced, and only part of the silver developed is used to bleach the dye. This results in a higher, but still inadequate, light sensitivity. This is because the silver halide emulsion is often chemically desensitized by azo dyes; from * everything, however, the 'sensitivity ver ~

009886/1631

lust caused by the fact that the dyes absorb light in the spectral sensitivity range of the emulsion, so that the light is attenuated in the layer and in the Depth of the layer no longer has any effect

This last-mentioned effect of the so-called Optical desensitization is particularly detrimental when the emulsion is in the sensitivity range and The absorption range of the dye lie in the same spectral range, but are not completely congruent »If for example one sensitized with a sensitizer Layer is colored with an image dye, the absorption maximum of which is at slightly shorter or longer waves lies as the sensitization maximum of the sensitizer, so the spectral sensitivity distribution is not easy evenly back, but two sensitization maxima form with one in between Sensitivity gap that leads to color distortions. |

These amendments are made according to the British patent specification 421 727 by not coloring the photosensitive layer, but separating the layer into an upper (i.e. facing the light source) colorless emulsion layer and a lower, non-light-sensitive, Layer stained with image dye »If you develop such a layer, you get one in the top layer Silver picture, under the influence of which, according to British patent * font 51 * 955 bleach the dye of the lower layer

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can »This" bleaching "is possible because the Parbleach catalyst (e.g. 2,3-diaminophenazine) on silver is activated so that the activated Porm migrates to the dye and there bleaches the dye · To carry out this Process one needs a lot of silver, long bleaching times and energetic bleaching conditions, which lead to undesirable color gradations. ..

Furthermore, the gradation of the images produced by the silver dye bleaching process is usually too steep, especially if you are in the specified manner with one only Silver overshoot, partly used for color lead, works. This disadvantage was also recognized early on and is combated, for example, according to German patent specification 733 728 by being in the presence of an oxidizing agent bleaches. This gives you a certain Flattening of the color image., But this is preferably done by extending the puss section of the color gradation curve, thus at the expense of sensitivity; in addition, one receives instead of a desirable straight (linearized) gradient, one by lengthening the foot area is strongly S-shaped deformed color gradation curve.

Another method for flattening the gradation is proposed in the American Patjentschrift 2,321,195 or 3 505th Then the layer is divided into two sections: a colored layer with a sensitive emulsion f

ORIGINAL INSPECTED

and another colored layer with a less sensitive emulsion. According to this method, too, the gradation is corrected at the expense of sensitivity.

Other disadvantages result from often nut * difficult- · controllable neighboring layer effects there were, difficult, color falsifications due to dye diffusion to prevent »In the American patent specification S 391 198 a material is proposed, which between the emulsion layers colored with non-diffusion-resistant dyes contains a separating layer containing emulsions., According to this patent specification, this is used in the interim schizliti image-wise, developed silver to bleach from de »bei Adjacent layers of color of diffused dye »Without

■. "■. · ■ .. ■ ■ j

The intermediate layer has the one established in the adjacent color layer; Dye color shifts result. In an intermediate layer without emulsion, the diffused dye remains as a color veil even when exposed to white. -... ■

Ba according to this patent specification worked in the absence of colored lead catalysts; is a noteworthy effect on the Eleiehuiig of the undiffused ^ Dye excluded.

■ There are also methods known (American Patent specification 2 I83 39Ψ and British patent specification 483 464), which proceed from colored emulsion layers and colorless emulsion layers, which are used to record different color

0 0 9886/1 S31 original .'inspected

ν:. '■ "■ · ■■■■ .;.. 6 -

impressions serve. In these proceedings; become the colorless ones Layers after black and white development Dyed image dyes «which are then used to generate images.

It has now been found that one can surprisingly avoid the disadvantages mentioned above, if one uses an emulsion layer containing a non-diffusible image dye and one of image dye Free emulsion layer combined, silver images developed in both layers, and the image dye in counter-? war a bleach catalyst bleaches * so that next to the An additional bleaching effect due to the layer's own silver Bleaching occurs due to the silver of the neighboring layer.

Through the interaction of near and

Fernblelchung receives

one has an effect that has a favorable effect on gradation «sensitivity and spectral distribution of sensitivity * Λ- - = ■ I ^: \: - ^:: -

The present invention is therefore

J / ■ ■■ "■■., * · 'For a process for producing a photographic

Color image according to the silver color bleaching process, characterized in that a photographic material which has at least one diffusion-resistant,; Containing bleachable image dye. ^{Silberhalogenidemul-:} immersion layer and immediately above it, on the side facing the light source, an image dye-free silver halide emulsion layer containing at least a high sensitivity equal to

008886/1631. ■. ■■■■ ·. 'original, inspected

" ⁷ " - "203S918

The possibility of how the coloring layer is, contains * as large as a picture exposed and in the presence of a color lead catalyst processed into a color image, the color image being exclusive is generated by image dyes present in the photographic material prior to exposure.

The fact that the colorless emulsion layer lies on the side facing the light source ensures that the sensitivity of the colorless layer is not subject to the “optical desensitization * ¹ caused by the image dye f the colorless layer is not only the same height * but higher than that of the colored layer. This is achieved in a simple manner by dividing a single base emulsion into two parts, adding one part of image dye, and pouring both parts on top of one another but: '■' - '■. ■. "' ■ '■.' ■■ ■■. '■ .. -. I.

for the two layers also of different emulsions * · ■ (different gradation and different sensitivity) j go out. The higher sensitivity of the colorless emulsion ' layer is set in such a way that the color gradation curve is linearized by correcting the shoulder area, i.e. one Is just approximated. This has to be determined empirically. The color gradation is corrected without loss of sensitivity or even with an effective gain in sensitivity. ·

Specifically, any desired deviations from the linearity of the gradation curves can also be achieved by choosing other sensitivity ratios in the two layers.

will. ■ '■ - "■■. ■" "" "■" .- *. ■■■■■ - -

009886/1631 ". '" "' ■" originally inspected

Even if, as is preferred, the base emulsion is the same for both layers, so one needs less emulsion in the colorless layer than in the colored layer in order to work in the colorless one Layer an at least .as high sensitivity reach. To achieve the desired linearization effect, it is sufficient in most cases to use the colorless emulsion layer, the poured amount of silver halide per unit area is the same or preferably represents only a fraction of that in the color layer, e.g. 10 to 100 #. The optical sensitization of the two layers belonging together is preferably in the same spectral region. But it is not necessary for both shifts to use the same optical sensitizer. For example, the maximum of the two sensitizations be shifted by a few nm e.g. up to + 25 nm, or the. The width of the sensitization areas can differ from one another. So, if necessary, the colorless layer can with a sensitizer which has a very narrow band in the region of the absorption maximum of the image dye to compensate for the mentioned sensitivity gap caused by optical desensitization. Additional sensitivities in other spectral ranges can be desirable to produce certain masking effects be. However, it is preferred in both adjacent layers the same sensitizer is used.

00988671631

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When the term colorless or dye-free emulsion layer is spoken of in this description, it is to be understood that this emulsion layer is free from image dye. This designation is not intended to exclude the possibility that it may contain a filter dye, the presence of which during exposure selectively reduces the spectral transmittance and / or increases the image sharpness. Such a filter dye is completely destroyed during processing in baths or washed out .. _etc.

The inventive method is suitable for Coloring and multicolor material. Really important but it is in making multicolor images because the requirement of the gradations and sensitivities of the To adapt the individual layers of paint to one another, the number of possibilities for variation is reduced. .

A multi-color material contains at least two silver halide emulsion layers containing image dye, wherein the image dyes are different from each other and can i one or more inventive double layers. These double layers can optionally be separated from other emulsion layers by intermediate layers, and these intermediate layers can also contain conventional additives such as filter dyes, UV absorbers or oxidizing agents.

Of particular interest is high color density photographic transparency material.

009886/1631

A preferred three color material according to the present invention The invention has the following structure:

sensitive to blue, colorless

blue sensitive, yellow

Yellow filter

sensitive to green, colorless

sensitive to green, purple

Intermediate layer (gelatin)

sensitive to red, colorless

sensitive to red, blue-green

Support, opaque or preferably transparent

Suitable color bleach catalysts are preferably used Pyrazines, quinoxalines or phenazines are used. With the image dyes it is usually azo dyes

Percentages in the following examples are percentages by weight.

009883/1631

Example 1 ·

The three two-layer materials A, B and C are poured onto a transparent carrier, all of them in gelatin and dye in the underlayers and in the overlayers Contain gelatin. Material A only contains silver bromide in the sub-layer, material B only contains silver bromide in the top layer, and material C contains silver bromide in both layers.

The dye has the formula

H-C

o- | ^ ii _Ä NYyco-im- <i3 - ii =

OH-,

and is applied at a transmission density of 2.0. The silver bromide is not optically sensitized; it will in the sub-layers (A and C) in an amount of 1.5 g Ag / m, and in the upper layers (B and C) in an amount

2
of 0.5 g Ag / m applied. The gelatine is dosed in such a way that all layers have a thickness of 2.5 μ each.

The three materials are behind a step wedge exposed with blue light and processed according to the following process!

009886/1631

Minutes developer ,

p-methylaminophenol sulfate 2 g

Sodium sulfite anhydrous 50 g

Hydroquinone. . 6 g

Sodium carbonate anhydrous 20 g

Potassium bromide 2g

1000 ml of water

Minutes of darning fixation bath . _t

Sodium thiosulphate crystallizes anhydrous sodium sulphite
Sodium acetate (5
Glacial acetic acid,

Water on

Soak for minutes.

Minutes of dye bleach

Water 500 ml

Sulfuric acid (96 %) 14 ml

Sodium hypophosphite crystallizes Ig

Potassium iodide 20 g 6-benzoylamino-2,3-4 ethyl

quinoxaline 3Q mg

Water on. 1000 ml

Water for minutes,

200 G 15th G 25th G 13th ml 1000 ml

009886/1631

6 minutes silver bleach bath

, Water 500 ml

Sulfuric Acid ($ 96) 27 ml

Copper sulfate crystallizes 20 g

Potassium bromide 60 g ■! ■■.

Water to 1000 ml

Soak for 2 minutes. '·

4 minutes fixation bath

¹ 'I.

Composition same as the stuffer bath. I.

Soak for 8 minutes.

Three color wedges A, B and C running in the same direction as the template are obtained, which are measured behind a blue filter.

The gradation curves A, B and C are shown on the curve diagram in FIG. On the abscissa are the wedge densities of the exposure wedge (exposure increases from left to right) and on - i

the ordinate plotted the density. This is also true

■■■ · ■■ ^:. '' .. ι

for the curves in FIGS. 2 to 4.

Wedge A is too steep. Wedge B is too flat and only partially bleached. Wedge C has the desired gradation. It is noteworthy that the material C has the same threshold sensitivity as material A. has that the gradations A and C are very similar in the foot areas; and that the picture C mainly by one Shoulder correction is flatter and with linearized gradation compared to image A.

009886/1631

-ι * - "- 2G36918

Example .2

The procedure is as in Example 1, but with following deviations:

The dye has the formula

<~ ^ -0G- <ZyMrCO - ^^

HO ₃ S SO ₃ H ₂

The silver bromide used is sensitized with a green sensitizer and the exposure is made with green light carried out. The three color gradations obtained are can be seen from the graph in FIG. 2;

With regard to curves A / B and C, that can The same can be said as in Example 1. i

Similar results are obtained if you instead of the specified color bleaching bath bleaches for 8 minutes in a bath containing 70 ml of 37 # hydrochloric acid per liter, 50 g potassium bromide, 80 g thiourea and 5 mg 2-amino-3-hydroxyphenazine contains.

009886/1631

- ¹ S-. ; 2038918

Example 3

A 2.5 μ thick layer with red light sensitized silver bromide (1.5 β Ag / m) and a blue-green paraffin of formula

OH OCH, HO

HO-S SO-H BLCO | ⁵ '* ^ SO »H

(Transmission density, 3.0) The material is poured into divided into three parts (A, B, C).

Aj ^ on part of the material rIr ^ ^ ine 2.5 μ thick Poured gelatin layer

Bj, on another part of the material is a 2.5 μ

thick layer poured containing identical sensitized ^v overbased silver bromide (0.5 g Ag / m ^0). :. *

Cj_ On a third part of the material, a 2.5 μ

A thick layer was poured, containing identical sensitized silver bromide (1.0 g Ag / m ² ).

After exposure behind a step wedge with red light and the usual processing analogous to Example 1 is obtained the three color images A, B and C. Through the colorless Eraul-

009886/1631

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203Ö918

Although the sion layer is a considerable gain in sensitivity, it is not yet an optimal linearization of the gradation achieved, as can be seen from FIG. 3 * The shoulder correction found for curves B and C compared to the gradation curve A shows, that one too here silver halide emulsion layers are present whose sensitivity is higher than that of the dye-containing Layer lies. The selected conditions are less, but not optimal, so that the linearization is not complete is.

009886/1631

'"" 2030918

Example 4

The procedure is as in Example 3, but with the difference that the silver bromide of the color layer and the silver bromide of the top layer can be sensitized in different ways, using the same sensitizer is used in different amounts.

A red sensitizer of the formula A is used to sensitize the silver broride in all layers

⁰¹ fe

used, 'I.

and 2wa | * the silver bromide of the colored layer is sensitized with 80 mg of sensitizer / 100 g of Ag, and the silver bromide of the colorless layer with only 40% of sensitizer / 100 g of Ag. After the same processing as in Example 3, the three images A, B and C are obtained. It can be seen from the gradation curves in FIG. 4 _r that, compared to the control test (A), a cover layer with

ο - ■

0.5 g Ag / m (B) and. even more with a deck cover 1.0 g Ag / m (C) both a gain in sensitivity and a linearization effect can be achieved.

'.-ORIGINAL.INSPECTED' -

009886/1831

Example 5

It becomes a material with the following layer arrangement

cast: '■ -. "...;" ■ 'V- ' "■", .-, '...... V ■

9 protective layer
8 AgBr sensitive to blue

7 AgBr blue-sensitive -f- yellow dye as in '

. "" Example 1 · V /. . .: '-. . . V. V

6 intermediate layer

5 AgBr green sensitive:

4 AgBr green sensitive * for purple dyes such as

in example 2 '

- 3 intermediate ^layer? ^

\: Z AgBr red sensitive -

1 AgBr red-sensitive for blue-green color as in - 'Example 3''. . _: \: _] ; -._;.;., _.-. ; ■ '■■' ■ carrier «transparent f

Only the protective layer (9) is made in a thickness.

1 * 5 μ-cast * · all "other layers (1-to 0)> earth: in '_ · ■

one thickness per 2 ^ 5 μ poured »The material is: /. . ., _; raJfc weissenij, blue bi * green unü rpteia.Jiiaht feellefetei ⁵ :: ■ ;; and as in example 1 yerarbeit @ t- »The. Measuring the change in the color ■■■ trowel zeigf ;, "let all colors uad Tou ^ rte in besseapeip way ⁷ reproduced werdött" than pfaotograptiisehe ": Material ,, the no Silberb3 enthälfe omidzwis®] isensQhiohten?. . . ■ -

. '-' '■. ■ ■ 'ORIGINAL INSPECTED

2036919

Example 6

The procedure is as in Example 1, however with the following deviations:

The substrate is not transparent, but white opaque. The image dye has the formula (3) and is applied in a reflection density of 2.0. | The silver bromide used has a red sensitivity JU sensitized; it is used in the sub-layers (material A and C) in an amount of 0.9 g Ag / m and in the top layers (material B and C) in an amount

of 0, ^ 5 g Ag / m applied. The exposure takes place with red light. The three color gradations obtained can be seen from the curve diagram in FIG. ·

With regard to curves A, B and C, the same can be said as in example 1. |

ORiGiNALlNSPECTEO

009886/1631

Claims (1)

;;. ■■■ 203Ö918 · . -, 20 "claims (l) A process for the production of a photographic color image by the silver dye bleaching process, characterized in that a photographic material which is formed on a support at least one silver halide emulsion layer containing a diffusion-resistant, bleachable image dye and immediately above it, on the side facing the light source, one of Image dye-free silver halide emulsion layer, which is at least as sensitive as the dye-containing layer, contains, imagewise exposed and processed into a color image in the presence of a dye * - bleach catalyst, the color image being produced exclusively by image dyes present in the photographic material before exposure . \ 2. The method according to claim 1, characterized in that that the dye-free silver halide emulsion occurs has a higher sensitivity than the dye-containing silver halide emulsion layer. 3. The method according to claim 2, characterized in that that the sensitivity of the dye-free silver halide emulsion layer is set so that the color gradation curve by correcting the shoulder area is' linear! - 009886/1631 2Ü3691S .ν - 21 - .. ■■■■; .. ' is sated. 4. The method according to any one of claims 1 to J>, characterized in that the dye-free and the dye-containing silver halide emulsion layer, which are adjacent to one another, are optically sensitized in the same spectral region. 5. The method according to claim k, characterized in that the dye-free and the dye-containing silver halide emulsion layers which are adjacent to one another are optically sensitized with the same sensitizer. 6. The method according to any one of claims 1 to 5, characterized characterized in that the dye-containing silver halide emulsion layer a calibratable azo dye as Contains image dye. i ■: i ■ -I ■ ■ '■ i 7. The method according to any one of claims 1 to 6, characterized characterized that a pyrazine, Quinoxaline or phenazine is used. 8. The method according to claim 7> characterized *: that the color bleaching catalyst? is in a photographic processing bath « i ORIGINAL! NSPECTEO 009886/1631 203G918 9. The method according to claim 7, characterized in that that the color bleach catalyst is in a layer of the photographic material to be processed is located. 10. The method according to any one of claims 1 to 9, characterized in that the dye-free layer contains 20 to 100% of the amount of silver halide of the dye-containing layer. ν 11. The method according to one of the claims! "To * 10, thereby characterized in that the photographic material contains at least two image dye-containing silver halide * contains emulsion layers in which the image dyes from each other are different. 12. The method according to any one of claims 1 to 11, characterized in that it is the photographic The material is a transparent material with a high density of parchment. 13. The method according to any one of claims 1 to ^12% characterized in that the färbstofffreie and the dye-holding strength Emulsionsschicnti contain the same basic emulsion. 008316/1631 -; ^; ^ ginal wspeerep Ik. The photographic color images obtainable by the process according to one of Claims 1 to 13. 15. That to carry out the procedure according to a of claims 1 to I3 used photographic material · · 009886/1631 blank KV *: