US2168182A - Photographic material for color photography - Google Patents

Description

Aug. 1, 1939. 1- B. wENDT 2,163,182

PHOTOGRAPHIC MATERIAL FOR COLOR PHOTOGRAPHY Filed Nov, 2s. 1937 d Blue '.Se/zslltive Ema/sion Layr;

Sup/Dort By His Alforneys Patented Aug. 1, 1939` UNITED STATES PHOTOGRAPHIC MATERIAL FOR COLOR PHOTOGRAPHY i Bruno Wendt, Dessau, Germany, assignor, by mesne assignments, to Agfa Ansco Corporation, Binghamton, N. Y., a. corporation of Delaware Application November 26, 1937, Serial No. 176,609 In Germany December 9, 1936 6 Claims.

This invention relates to color photography.

For producing subtractive multi-color photographic pictures several silver halide emulsion layers containing dyestulf components have been 6 superimposed on each other on a carrier, in particular arrangement of'versuper-imposed layers, namely three emulsion layers having two intermediate layers serving as filters or separating layers, has been found advantageous. It l has also been proposed to arrange several sensitive silverhalide emulsions in the form of small particles ona carrier. This latter photographic material has in particular the disadvantage that the pictures produced' thereonV show a grainy appearance. i

It is an object of the present invention to provide an improved photographic material in which the disadvantages incurred with the aforementioned materials are avoided.

`Av further object is a photographic material in which the number .of necessary emulsion layers is decreased in comparison with the hitherto used multi-layer materials.

A further object is to provide a material in 25 which the grainy structure of one layer is made to disappear substantially.

Further objects reside in the preferred -and suitable arrangement of the layers in the photographic element.

Further objects wi11 be apparent from the de` tailed specification following hereafter.

The invention consists in arranging several sensitive silver halide emulsions having dyestuif components on a carrier, at least one silver 35 halide emulsion being in the form of nely subdivided particles and atleast one silver halide emulsion being in the form of a layer. Thus, two

diierently sensitized silver halide emulsions hav-.

Fig. 1 is a diagrammatical View of a multilayer photographic material in an exaggerated scale and Fig. 2 is a diagrammatical view of a single layer photographic material according to the invention.

In the gures like characters indicate corresponding parts.

In Fig. 1 a is a support, b represents a gelatin layer, c represents a yellow filter layer, d represents a blueA sensitive silver halide emulsion layer, e indicates theparticles of a silver halide emulsion sensitized to green and containing a dyestuff component fast 'to diffusion caco pable oi' being transformed into a purple dye, I

reference to the accompanying drawing, in which.'

indicates the particles of a silver halide emulsion sensitized to red' and containing a dyestuff component for blue-green of the kind herein referred to. n

In Fig. 2 a is a support, g represents a bluesensitive silver halide emulsion layercontaining a dyestuff component capable of yielding a vyellow dye, h indicates the particles of a silver halide emulsion sensitized to green and dyed yellow, s'aid particles containing a dyestuif component adapted to form a purple picture, i indicates the particles of a silver halide emulsion sensitized to red and dyed yellow, said particles containing a dyestuifA component for the-blue-green picture.

A suitable photographic material, for example, l5 -comprises on a carrier a layer vof a mixture of` particles distributed in gelatin of a green-sensitive hardened silver halide emulsion provided with a dyestuif former fast to diffusion and capable of conversion into a purple dyestui and a red-sensitive hardened silver halide emulsion provided with a dyestuff former fast to dilusion and capable of conversion into a blue-green dyestuff, and over this a yellow-dyed layer, and above this again a layer of a blue-sensitive silver halide emulsion provided with a dyestuif former capable of conversion into a yellow dyestuff.l Preferably the yellow-dyed layer and the layer consisting of a blue-sensitive silver halide emulsion provided with a dyestuif former capable ol' 30 conversion into a yellow dyestuff are united to a single layer by dyeing this single layer yellow and providing it with a dycstui former capable of conversion into a yellow dyestuif.

A single layer material for color photography may be made by distributing emulsion particles of a pre-sensitized yellow-dyed silver halide emulsion containing a dyestuif former capable of conversioninto a purple dyestuif and the particles of a red-sensitized yellow-dyed silver halide 40 emulsion containing a dyestuff former capable of conversion into a blue-green dyestuff in a bluesensitive silver halide emulsion containing a dyestuff former capable of conversion to a yellow dyestui. In this case it is of advantage that l the blue-sensitive emulsion -constituent .should constitute more than one-third of the total mass vof emulsion.

As dyestuif formers for these silver halide emulsion ,layers there may be used with advantage components which by introduction of certain radicals have been made fast to diffusion as regards the binding agent. As described in U. S. patent Aapplication Ser. No. 72,718 led April 4, 1936, there may be introduced into the dyestu components groups which lend a substantive character to the molecule of the dyestull' former. As described in U. kS. patent application Ser. No. 90,726 led July 15, 1936, the dyestui components may be made fast to diiusion by introducf ing radicals of highly polymeric carboxylicacids or their derivatives. Further, dyestuil' components are fast to diffusion when, as described in U. S. patent application Ser. No. 94,340 iiled August 5. 1936, they contain carbon chains of more than carbon atoms or, according to U. S. patent applicationSer. No. 158,860 led August 13, 1937, polypeptide radicals or as described in U. S. patent application Ser. No. 159,518 illed August 17, 1937, carbohydrate radicals, or as described in U. S. patent application Ser. No. 164,499 filed September 18, 1937, when they contain radicals of resins or, as described in U. S. patent application Ser. No. 166,832 illed October 1, 1937, when they contain sterol radicals. Moreover, dyestuff components fast to diiusion are obtained when the dye-forming groups are coupled to yield a molecule of chain form as described in the U. S. patent application Ser. No. 171,70l led October 29, 1937. There may also be used dyestui components fast to diffusion, as described in U.- Sl patent application Ser. No. 10,704 illed March 12, 1935, in which case the dyestui picture is produced by aac-coupling. In like. manner there are suitable silver halide emulsions whichcontain color iormers fast to dliusion, as

described in U. S. patent application Ser. No.

111,250 filed November 7, 1936, in which the color picture is produced by destroying directly or indirectly the dyestui former or the dyestufi which has been formed over the silver image.

For example. if the three emulsions contain leuco-dyestus fast to diffusion which have developing properties for silver halide, there is obtained a dyestuil image in the place of the silver image. The same is the case when suitable components for the color development are added to vthe emulsion and the development is conducted by means of a 4suitable developer.

There are obtained in` this manner complementarily colored negatives irom which copies may be lproduced onthe same material which are positives in the correct colors. By destroying the colors rst formed and converting the residual components;- into dyestufis, there is produced a positive correctly colored picture, also by development of the negative with a non-dyeing developer togeth'er with subsequent second development, for

` example by the. process described in U. S. patent applications ser. No. 100,319 sled september 11,

' 1936, and SeriNo. 148,731 iiled June 17, 1937.

T he material is also suitable for any other process, provided a color former suitable for the process used is incorporated with the emulsion, for example if, as described in the German Patent No. 396,485, thereis used a color former which loses its capacity for forming the color at the places which contain silver, the residue oi4 the -dyestui former is converted into a positive of correct color.

Y as described in U. S. patent application Ser. No.

.72,714 filed April 4, 1936. Color formers which do not possess sufiicient fastness to diiusion may be madesufiiciently insoluble by addition of a 'known precipitating agent.

The photographic material herein prescribed is applicable in all cases in which hitherto subtractive multi-color pictures have been produced directly'or by means orany component c'olor pictures or other multi-color copies.

What I claim is:

l. A light-sensitive elemen't for color photography comprising a support and a plurality of sensitized silver halide emulsions, each of .saidv emulsions containing a dyestuf! component fast to diiusion and capable of forming a dye selected from the group consisting o! quinoneimineand azomethine dyes with the oxidation product of a developer and at least one light-sensitive silver halide emulsion layer containing a dyestuff component of the same kind.

3. A light-sensitive element for color photography comprising a support, a gelatin layer in direct contact with said support containing hardened microscopic particles of two diiierently sensitized silver halide emulsions, one type v01 par-- ticles being sensitized to green and containing a dyestuil' component fast to diiusion capable o! forming a purple dye and the second type being sensitized to red andcontaining a dyestuil component fast to diilusion capable of forming a blue-green dye, a silver halide emulsion layer on said gelatin layer containing a dyestuii component fast to diffusion and capable of forming a yellow dyestuil.

4. A' light-sensitive element ior color photography comprising a support, a gelatin layer in direct contact with said support containing hardened microscopic particles of. two diiierently Lcomponent fast to diffusion capable of forming a blue-green dye, a yellow illter layer on said gelatin layer, a silver halide emulsion layer vcontain-- 'ing a dyestii component fast to diiiusion capable of forming a yellow dyestufi.

5. ,A light-sensitive silver halide emulsion layer comprising a support, a blue-sensitive silver halide emulsion layer containing a dyestu'fi component fast to diffusion and capable of forming a-yellow dye, microscopic particles of a hardened `,silver halide emulsion sensitized to green and dyed yello'w' distributed in said emulsion layer, said particles .containing a dyestufi component fast to diil'usion and adapted to form a purple dye, microscopic particles of a hardened lightsensitive silver Vhalide emulsion dyed yellow distributed in said emulsion layer, said particles containing a dyestu component fast to diilusion landadapted to form a blue-green dye.

6. A light-sensitive element for color photography` according to claim 5, .the blue-sensitive emulsion, layer comprising more than one-third of the entire weight of the emulsion.

BRUNO WENDT.

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