EP0809140B1 - Colour photographic recording material having increased sensitivity and improved colour reproduction - Google Patents

Description

Usually for the spectral sensitization of the blue, green and red Structurally different dyes are used in the spectral range (see e.g. DE-A-42 31 770, DE-A-44 23 129, DE-A-44 04 003, DE-A-44 33 637, DE-A-4434971.

Efforts have not been lacking in the well-known color photographic recording materials with regard to their spectral sensitivity and their color rendering to improve. EP-A-0 409 019 discloses a color photographic recording material described and claimed with improved color rendering, which thereby is achieved that both the green sensitive and the red sensitive Silver halide emulsion layers by using one or more so-called gap sensitizing dyes an additional sensitization for Light from the gap between the neighboring main spectral ranges green and Get red. This will make the adjacent spectral sensitivity curves raised in the area of the secondary spectral sensitivity (gap), so that at most 0.6 logarithmic exposure units in the area of the secondary spectral sensitivity are required to have the same color density as in the range of to generate neighboring main spectral sensitivities.

EP-A-474 193 describes a silver halide color photographic material in which the Sensitivities of the low-, medium- and high-sensitive red-sensitive Emulsion layers at certain wavelengths in fixed ratios to each other stand and in which the red-sensitive emulsion layer of medium sensitivity contains a combination of several sensitizers. It's supposed to be greenish Avoided when taking photographs even under fluorescent lighting conditions become.

In the comparison materials of EP-A-575 927 contain the red and green sensitive Silver halide layers are identical in all layers, at 527 nm absorbing sensitizer. The achieved in addition to the sensitivity gain Color rendering improvements are not yet sufficient.

It has now been found that not only sensitivity, but also color rendering can be improved if additional cyanine dyes with certain spectral absorption properties for both sensitization in the green spectral range as well as for sensitization in the red spectral range are used, the absorption being used in the green spectral range additional dyes from the absorption of those in the red spectral range used dyes differs.

The invention relates to a color photographic recording material a layer support and at least one red-sensitive one arranged thereon Silver halide emulsion layer with a cyan coupler, at least one green sensitive Silver halide emulsion layer with a magenta coupler, at least a blue sensitive silver halide emulsion layer with a yellow coupler and optionally further, non-light-sensitive layers, characterized in that that at least one of its red sensitive silver halide emulsion layers and at least one of its green sensitive silver halide emulsion layers in addition to the usual sensitizing dyes, at least one each Contain cyanine dye, which has a maximum absorption in methanolic solution in the range of 517 - 540 nm, the absorption maximum of the additional Cyanine dye in the red-sensitive silver halide emulsion layer and the Absorption maximum of the additional cyanine dye in the green sensitive Layer, each measured in methanolic solution, by at least 1 nm and by are not more than 10 nm apart.

The additional cyanine dyes mentioned are preferably carbocyanines, the one with at least one of the (two) ring nitrogen atoms Acid-substituted alkyl group. Particularly suitable examples of these Cyanine dyes belong to the class of benzimidazole carbocyanines or Substance class of the oxathiacarbocyanines.

Some "additional" cyanine dyes suitable according to the invention are given below by way of example with the corresponding absorption maxima λ _max measured in methanolic solutions.

Examples of color photographic materials are color negative films, color reversal films, Color positive films, color photographic paper, color reversal photographic Paper, color-sensitive materials for the color diffusion transfer process or the silver color bleaching process.

The photographic materials consist of a support on which at least one photosensitive silver halide emulsion layer is applied. Suitable as a carrier especially thin films and foils. An overview of carrier materials and on the front and back of the auxiliary layers is in Research Disclosure 37254, Part 1 (1995), p. 285.

The color photographic materials usually contain at least one red-sensitive, green sensitive and blue sensitive silver halide emulsion layer and optionally intermediate layers and protective layers.

Depending on the type of photographic material, these layers can vary be arranged. This is shown for the most important products:

Color photographic films such as color negative films and color reversal films show in in the following order on the carrier 2 or 3 sensitive to red, cyan-coupling silver halide emulsion layers, 2 or 3 green-sensitive, purple-coupling silver halide emulsion layers and 2 or 3 blue-sensitive, yellow-coupling silver halide emulsion layers. The layers are the same spectral sensitivity differ in their photographic sensitivity, the less sensitive sub-layers usually closer to Carriers are arranged than the more sensitive sub-layers.

Between the green sensitive and blue sensitive layers is common a yellow filter layer is applied, which prevents blue light from entering the to get layers below.

Color photographic paper, which is usually much less sensitive to light as a color photographic film, points in the order given below usually a blue-sensitive, yellow-coupling silver halide emulsion layer on the support, a green sensitive, purple coupling silver halide emulsion layer and a red sensitive, cyan-coupling silver halide emulsion layer on; the yellow filter layer can be omitted.

Deviations in the number and arrangement of the photosensitive layers can occur to achieve certain results. For example, you can all highly sensitive layers in one layer package and all low-sensitive layers Layers to another layer package in a photographic film be summarized to increase the sensitivity (DE 25 30 645).

The possibilities of the different layer arrangements and their effects the photographic properties are described in J. Int. Rec. Mats., 1994, Vol. 22, pages 183-193.

Essential components of the photographic emulsion layers are binders, Silver halide grains and color couplers.

Information on suitable binders can be found in Research Disclosure 37254, part 2 (1995), p. 286.

Information about suitable silver halide emulsions, their preparation, maturation, Stabilization and spectral sensitization including suitable spectral sensitizers can be found in Research Disclosure 37254, Part 3 (1995), pp. 286 and in Research Disclosure 37038, Part XV (1995), p. 89.

Photographic materials with camera sensitivity usually contain silver bromoiodide emulsions, which may also contain small amounts of silver chloride can contain. Photographic copying materials contain either silver chloride bromide emulsions with up to 80 mol% AgBr or silver chloride bromide emulsions with over 95 mol% AgCl.

Information on the color couplers can be found in Research Disclosure 37254, Part 4 (1995), p. 288 and in Research Disclosure 37038, Part II (1995), p. 80. The maximum absorption of that from the couplers and the color developer oxidation product Dyes formed are preferably in the following areas: Yellow coupler 430 to 460 nm, purple coupler 540 to 560 nm, cyan coupler 630 up to 700 nm.

In color photography films, to improve sensitivity, Graininess, sharpness and color separation are often used in compounds React with the developer oxidation product to release compounds that are photographic are effective, e.g. DIR couplers that release a development inhibitor.

Information on such connections, in particular couplers, can be found in Research Disclosure 37254, Part 5 (1995), p. 290 and in Research Disclosure 37038, Part XIV (1995), p. 86.

The mostly hydrophobic color coupler, but also other hydrophobic components of the Layers are usually found in high-boiling organic solvents dissolved or dispersed. These solutions or dispersions are then in one emulsified aqueous binder solution (usually gelatin solution) and lie after drying the layers as fine droplets (0.05 to 0.8 µm diameter) in the layers before.

Suitable high-boiling organic solvents, methods for incorporation into the layers of a photographic material and other methods, chemical Introducing connections into photographic layers can be found in Research Disclosure 37254, Part 6 (1995), p. 292.

The usually between layers of different spectral sensitivity arranged non-light-sensitive intermediate layers can contain agents which an undesirable diffusion of developer oxidation products from a photosensitive to another photosensitive layer with different prevent spectral sensitization.

Suitable connections (white coupler, scavenger or EOP catcher) can be found in Research Disclosure 37254, Part 7 (1995), p. 292 and in Research Disclosure 37038, Part III (1995), p. 84.

The photographic material can also contain UV light-absorbing compounds, white toners, spacers, filter dyes, formalin scavengers, light stabilizers, antioxidants, D _min dyes, additives to improve the stability of dyes, couplers and whites and to reduce the color fog, plasticizers (latices), Contain biocides and others.

Suitable compounds can be found in Research Disclosure 37254, Part 8 (1995), P. 292 and in Research Disclosure 37038, parts IV, V, VI, VII, X, XI and XIII (1995), p. 84 ff.

The layers of color photographic materials are usually hardened, i.e. the binder used, preferably gelatin, is made by suitable chemical Process networked.

Suitable hardener substances can be found in Research Disclosure 37254, Part 9 (1995), p. 294 and in Research Disclosure 37038, Part XII (1995), page 86.

After photographic exposure, color photographic materials become their character processed according to different processes. Details of the Procedures and chemicals required for this are in Research Disclosure 37254, part 10 (1995), p. 294 and in Research Disclosure 37038, parts XVI to XXIII (1995), p. 95 ff. Published together with exemplary materials.

example 1

A color photographic recording material for color negative color development was produced (layer structure 1A - comparison) by applying the following layers in the order given to a transparent cellulose triacetate support. The quantities given relate to 1 m ² . The corresponding amounts of AgNO ₃ are given for the silver halide application. All silver halide emulsions per 100 g of AgNO _{3 were} stabilized with 0.1 g of 4-hydroxy-6-methyl-1,3,3a, 7-tetraazaindene.

Layer structure 1A

Layer 1:

(Antihalo layer) with black colloidal silver sol

0.3 g Ag

1.2 g gelatin

0.4 g UV absorber XUV-1

0.02 g tricresyl phosphate (CPM)

Layer 2:

(Intermediate layer) 1.0 g gelatin

Layer 3:

(1st red-sensitized layer, slightly sensitive) Red-sensitized silver bromide iodide emulsion (4 mol% iodide; average grain diameter 0.5 µm; spectrally sensitized with the sensitizing dyes XRS-1, XRS-2 and XRS-3 in a ratio of 1: 3: 0.5 ) from 2.7 g AgNO ₃ , with

2.0 g gelatin

0.88 g cyan coupler XC-1

0.05 g colored coupler XCR-1

0.07 g colored coupler XCY-1

0.02 g DIR coupler XDIR-1

0.75 g CPM

Layer 4:

(2nd red-sensitized layer, highly sensitive) Red-sensitized silver bromide iodide emulsion (12 mol% iodide; average grain diameter 1.0 µm; spectrally sensitized with the sensitizing dyes XRS-1, XRS-2 and XRS-3 in a ratio of 1: 3.1: 0, 3) from 2.2 g of AgNO ₃ , with

1.8 g gelatin

0.19 g cyan coupler XC-2

0.17 g CPM

Layer 5:

(Intermediate layer)

0.4 g gelatin

0.15 g white coupler XW-1

0.06 g aluminum salt of aurintricarboxylic acid

Layer 6:

(1st green-sensitized layer, slightly sensitive) Green-sensitized silver bromide iodide emulsion (4 mol% iodide; average grain diameter 0.35 µm; spectrally sensitized with the sensitizing dyes XGS-1, XGS-2 and XGS-3 in a ratio of 2.8: 1: 0 , 2) from 1.9 g AgNO ₃ , with

1.8 g gelatin

0.54 g XM-1 magenta coupler

0.065 g colored coupler XMY-1

0.24 g DIR coupler XDIR-1

0.6 g CPM

Layer 7:

(2nd green-sensitive layer, highly sensitive) Green-sensitized silver bromide iodide emulsion (9 mol% iodide; average grain diameter 0.8 µm; spectrally sensitized with the sensitizing dyes XGS-1, XGS-2 and XGS-3 in the ratio 2.8: 0.9: 0.25) from 1.25 g AgNO ₃ , with

1.1 g gelatin

0.195 g magenta coupler XM-2

0.05 g colored coupler XMY-2

0.245 g CPM

Layer 8:

(Yellow filter layer)
yellow colloidal silver sol with

0.09 g Ag

0.25 g gelatin

0.08 g Scavenger XSC-1

0.40 g formaldehyde scavenger XFF-1

0.08 g CPM

Layer 9:

(1st blue-sensitive layer, slightly sensitive) Blue-sensitized silver bromide iodide emulsion (6 mol% iodide; average grain diameter 0.6 µm; spectrally sensitized with the sensitizing dye XBS-1) from 0.6 g AgNO ₃ , with

2.2 g gelatin

1.1 g yellow coupler XY-1

0.037 g DIR coupler XDIR-1

1.14 g CPM

Layer 10:

(2nd blue-sensitive layer, highly sensitive) Blue-sensitized silver bromide iodide emulsion (10 mol% iodide; average grain diameter 1.2 µm; spectrally sensitized with the sensitizing dye XBS-1) from 0.6 g AgNO ₃ , with

0.6 g gelatin

0.2 g yellow coupler XY-1

0.003 g DIR coupler XDIR-1

0.22 g CPM

Layer 11:

(Mikratschicht)
Mikrat-silver bromide iodide emulsion (0.5 mol% iodide; average grain diameter 0.06 µm) from 0.06 g AgNO ₃ , with

1.0 g gelatin

0.3 g XUV-2 UV absorber

0.3 g CPM

Layer 12:

(Protective and hardening layer)

0.25 g gelatin

0.75 g hardener XH-1,

so that the total layer structure had a swelling factor of 3.5 after curing.

Compounds used in layer structure 1A:

Sensitizing dyes used in Example 1:

In the further comparison layer structures 1B and 1C and in the inventive ones Layer structures 1D, 1E and 1F became the spectral sensitization changed as follows:

Layer structure 1B

layer Dyes used mixing ratio 3 F-1, XRS-2, XRS-3 1: 2: 0.3 4 F-1, XRS-2, XRS-3 1: 1.9: 0.4 6 XGS-1, XGS-2, XGS-3 (= F-1) 2.8: 1: 0.2 7 XGS-1, XGS-2, XGS-3 (= F-1) 2.8: 0.9: 0.25

Layer structure 1C

layer Dyes used mixing ratio 3 F-1, XRS-4, XRS-5 1: 2: 0.35 4 F-1, XRS-4, XRS-5 1: 2.1: 0.3 6 XGS-1, XGS-2, XGS-3 (= F-1) 2.8: 1: 0.2 7 XGS-1, XGS-2, XGS-3 (= F-1) 2.8: 0.9: 0.25

Layer structure 1D

layer Dyes used mixing ratio 3 F-2, XRS-4, XRS-5 1: 2.1: 0.25 4 F-2, XRS-4, XRS-5 1: 2: 0.3 6 XGS-1, XGS-2, XGS-3 (= F-1) 2.8: 1: 0.25 7 XGS-1, XGS-2, XGS-3 (= F-1) 2.8: 1.1: 0.2

Layer structure 1 E

layer Dyes used mixing ratio 3 F-3, XRS-4, XRS-5 1: 2: 0.35 4 F-3, XRS-4, XRS-5 1: 2.2: 0.25 6 XGS-1, XGS-2, F-2 2.8: 1.1: 0.3 7 XGS-1, XGS-2, F-2 2.7: 1: 0.3

Layer structure 1F

layer Dyes used mixing ratio 3 F-2, XRS-2, XRS-3 1: 2: 0.3 4 F-2, XRS-2, XRS-3 1: 1.9: 0.4 6 XGS-1, XGS-2, F-3 2.8: 1: 0.3 7 XGS-1, XGS-2, F-3 2.7: 1.1: 0.25

After exposure of a gray wedge, the layer structures 1A to 1F were made a color negative process, which is published in "The British Journal of Photography "1984, pages 597 and 598.

The sensitivities E _purple and E _{blue-green of} the layer structures 1B to 1F are compared in Table 1 to those of the comparison layer structure 1A. Table 2 summarizes the results of the Cielab measurements, which were used to characterize the color shift. Only the colors that are changed particularly strongly are mentioned.

Cielab measurements have long been used as a colorimetric description of CN films used. The method is detailed e.g. in R.W.G, Hunt "The

Reproduction of Color ", Fountain Press (1988). In addition to the color saturation, the color shift is an important feature in the characterization of CN films compared to the respective standard color charts. A low number in Table 2 means that the deviation from the original is small is and the film can be assessed particularly cheap. layer structure E _purple E _teal 1A 100 100 1B 105 130 1C 105 135 1D 110 125 1E 105 135 1F 115 140 Hue shifts [rel. CIELAB units] layer structure Blue flower purple modern red purple yellow-green 1A 12 14 9 12 9 1B 2 3 6 6 4 1C 3 5 5 4 5 1D 3 2 3 4 5 1E 0 1 2 3 4 1F 2 3 4 5 4

Claims (1)

1. Colour photographic recording material having a film support and, arranged thereon, at least one red-sensitive silver halide emulsion layer containing a cyan coupler, at least one green-sensitive silver halide emulsion layer containing a magenta coupler, at least one blue-sensitive silver halide emulsion layer containing a yellow coupler and optionally further non-photosensitive layers, characterized in that at least one of the red-sensitive silver halide emulsion layers thereof and at least one of the green-sensitive silver halide emulsion layers thereof each contain, in addition to conventional sensitizing dyes, at least one cyanine dye having an absorption maximum in a methanolic solution in the range from 517 to 540 nm, wherein the absorption maximum of the additional cyanine dye in the red-sensitive silver halide emulsion layer and the absorption maximum of the additional cyanine dye in the green-sensitive silver halide emulsion layer, in each case measured in a methanolic solution, are no less than 1 nm and no more than 10 nm apart.