US2028279A - Photographic material - Google Patents

Description

Jan. 21, 1936. B. GASPAR PHQTOGRAPHIC MATERIAL Filed. Dec. 1, 1932 Y ELEOW METALLIC 5ILVER Bela Gqs l Patented Jan. 21, 1936' PATENT f o-F lc-E PHOTOGRAPH) MATERIAL Bela Gaspar, Berlin, Germany Application December 1, 1932, Serial No. 645,313

In Germany December 2, 1931 7 Claims. (01. 95-2) This invention relates to photographic materials, and more particularly to colored silver halide layers.

It is known to produce two-color films by col-v oring films, which a sensitized on both sides, alter the tanning or mordanting process, on the one side red and on the other side green. It has been proposed to employ for coloring purposes mixtures of dyestufis, which color the layer to difierent degrees, whereby the silver salt employed as mordant should reveal a varying selectivity as regardsthe single parts of the dyestufi mixture of the dye solution. method is intended to result in a two-color image, in which the ,efiect is similar to that of three-color images. After the tanning of the layer, the one color is removed atpoints, and recoloring performed with a second color. It is also known to produce two-color films in which the dyestufi is incorporated in-the layer.

Silver halide layers have already been proposed, which contain mixtures of dyestuffs, for example one or more sensitizing dyestuffs and a filter dyestuff. These dyestuils, however, incorporated in the layer, have been employed in low concentration and do not serve towards the production of a dyestufi image.

' Now it has been found that two-color images may be obtained having a great similarity with three-color images, if sensitized layers are employed, containing dyestufiswhich possess varying powers of resistanceagainst an agent or solvent destructive to the dyestufi, more particularly oxidizing or reducing agents.

Accordingly, it will be apparent that the prestrated as shown in the accompanying drawing 45 in which Figures 1 and 2 are diagrammatic views illustrating one embodiment of the invention to be later described in detail.

, Two layers, of whicli the one is colored red and the other green, are either poured one over 50 theother on. adesired support.-- or backing; or

applied to both sides of a film, or also poured on the single films, which-are intended to be afterwards united to form a compound film. It is possible to obtain with the-photographic ma- 65 terial prepared in this manner avery wide range This of efiects; and the particular object of use may also be considered when selecting the dyestufls to be added to the emulsion.

For example for portrait work in order to ob-' tain proper flesh "color, also for interior work, 5 there is employed for the red colored layer a dyestufi mixture, which contains a rapidly bleaching purple red" and a slowly bleachin orange or yellow. The blue-green dyeemployed for coloring purposes will be, in accordance with 10 the invention, a blackish green. In the bluegreen part of the image'there will be employed a. reddish orange dye in place of the yellow dye, and a blue, which bleaches more readily than the yellow-orange. The desired color combination may be provided in one or more layers.

Example orange portion a mixture of dyestuffs containing a rapidly bleaching red and a more slowly 2 bleaching yellow dyestuff. I

The blue-green layer will contain a dyestufl mixture, in which. the yellow dyestufi bleaches more rapidly than the blue, in view of the fact that this layer is intended for the reproduction 3 of sky and foliage. 0

Example -The one layer is colored withAzo Fuchsine and Mordant Yellow GG, the other with Benzo Pure Blu and Metanil Yellow.

It is, however, also possible to produce various other combinations in accordance with the desired eiIect. Two-color films may be produced in fantastic colors Zemployed, Iorexample-for advertising purposes or in revue scenes. For example the one layer contains a mixture of red and violet dyestuif andis'colored purple-mauve. The other layer is colored yellow-green and contains a yellow and a blue-green dyestufi. The layers are sensitized in respect of rays, which are allowed to pass by-the dyestufi employedior coloring the layer, and under certain circumfstances for rays whichare allowed to pass by the layersituatecl thereover. The layers are then exposed, developed and subsequently treated, for example according to the method described in my prior Patent N0.'2,020,775, patented November 12, 1935.

By reference to the drawing, it may be pointed out that Fig. 1 represents across-section through a developed and fixed photographic layer. ABC and DEF are two silver deposits. This layer is colored blue (vertical shading) and yellow (horizontal shading). The two dyestufls are diffusely distributed so that prior to the destruction of the dyestufi the layer appears green;

Fig. 2 shows a cross-section after the destruction of the dyestufi at the points of the silver image proportional to the quantity of silver present (A'BC and DE'Ff)- Below the broken line all yellow has been destroyed and onlyblue remains. Above the broken line, in the neighbourhood of the silver all yellow has been destroyed, while at the center, at the points indicated by the horizontal shading, yellow still remains. This part, therefore, is agreen-blue.

To obtain the pure dyestuff image the remaining silver is discharged by means of Farmer's reducer.

A'C'GH is colored blue, GID'E' is also GHI is yellow and blue, i. e. green.

The treatment of the exposed material may, however, also be such that, for example, the layer is hardened by tanning development or blue subsequent'tanning. and this layer subjected tothe action of a solvent, as set forth by Schinzel in the Chemikerzeitung, 1908, page 667. In this case the procedure in the selection of the dyestuffs will be such that in place of the dyestuffs of different bleaching rapidity variously soluble or variously reacting dyestuffs will be employed.

The dyestufis employed may be identified by reference to Schultz Dyestufi Tables, 5th Edition, 1920. The index numbers for the particular colors herein specified are as follows: Py-

ramine Orange, R. 360; Azo Fuchsine, 71; Ben'zo Pure Blue, 426; Mordant Yellow GG, 48; Metanil Yellow, 134.

What I claim is:--

1. A color-photographic material, comprising a silver halide emulsion having incorporated therein differently colored dvestufis having varying powers of resistance to the effect of the agent serving locally to discharge the said dyestuffs for production of the color image.

2. A color-photographic material, comprising a silver halide emulsion having incorporated therein difierently colored dyestuffs adapted to bleach with varying rapidity under the action of I an oxidizing agent serving locally-to produce the color image.

3. A color-photographic material, comprising a silver halide emulsion having incorporated therein differently colored dyestufis adapted to bleach withvarying rapidity under the action of a reducing agent serving locally to produce the color image.

.4. A photographic material comprising a support having thereon a homogeneously colored sensitized silver halide emulsion containing different colored dyestuffs in high concentration and of difierent stability with respect to a reducing agent.

5. A photographic material comprising a support having thereon a plurality of layers of homogeneously colored sensitized silverhalide emulsion, each containing a diflerently colored dyestufi in high concentration and of diflerent stability with respect to a common reducing agent.

6. A photographic material comprising a support having thereon a plurality of layers of homogeneously colored-sensitized silver halide emulsion, one layer containing a red dyestufl mixture comprising rapidly bleaching purple and red and a slowly bleaching yellow in high concentration and another layer containing a bluegreen dyestufi mixture also in ,high concentra-' tion and containing a reddish orange and a blue BELA GASPAR.

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