US2166049A

US2166049A - Method of and material for producing multicolor images

Info

Publication number: US2166049A
Application number: US177344A
Authority: US
Inventors: Gaspar Bela
Original assignee: Individual
Current assignee: Individual
Priority date: 1937-11-30
Filing date: 1937-11-30
Publication date: 1939-07-11
Anticipated expiration: 1956-07-11
Also published as: GB521961A

Description

July 11, 1939. A A 2,166,049

METHOD OF AND MATERIAL FOR PRODUCING MULTICOLCR IMAGES Filed Nov. 30, 1957 l i 4.5UPPORT 1. BLUE SENSITIVE YELLOW FILTER DYE ZGREENSENSiTH/E SILVER HALIDE LA CONTAINING A D YE \lFOR YELLOW 5, RED SENSITWE ZFOR MAGENTA FORMING SUBSTANCE anveml'oz BELA 'GASPAR 4 Patented J l 11, 1939 Hatfield METHOD OF AND MATERIAL FOR PRODUC- ING MULTICDLOR IMAGES Bela Gaspar, Brussels-Forest, Belgium Application November 30, 1937, Serial No. 177.3%

8 Claims.

The present invention relates to a light sensitive photographic material comprising a plurality of superimposed silverhalide layers each of which is predominantly sensitive to one of the three primary colors blue, green, and red respectively. The materialallows the production of multicolor images and is especially suitable for exposures in a photographic or kinematographic camera.

The light sensitive material is schematically shown in the annexed drawing, in which the arrangement of the superimposed layers, their sensltivity and their coloration are indicated. The support 4 formed by a transparent material carries three layers l, 2, 3 in superposition. Layer l which is next to the support is an ordinary blue sensitive silver halide emulsion and contains a dyestuff forming substance from which a yellow azodyestuff can be produced by appropriate treatment. Layer 2 is formed by an orthochromatic emulsion predominantly sensitive to green light. This layer contains a dyestufi forming substance capable of being transformed into a magenta azodyestuflf. Layer 3 is formed by a red sensitive silver halide layer. Filter dyestuffs which can be washed out from the layers may be present as well in layer 2, as in layer 3, the filter dyestufl in layer 2 being yellow and the filter dyestuff present in layer 3 being red.

In the multilayer material the blue sensitive layer is arranged next to the support and the material is exposed with the support facing the light source during exposure or the objective of the camera. After exposure the top layer 3 is diffusely colored by a blue-green dyestuff, preferably an azodyestufi. It is recommended to incorporate a precipitating agent into layer 3 prior to exposure in order to precipitate and thereby to fix the dyestull when treating the surface with the dyestuff solution after exposure, as described in my co-pending U. S. application Ser. No. 86,427 now Patent No. 2,137,336, Nov. 22, 1938.

The dyestufl forming substances present in layers l and 2 are transformed into dyestuffs after exposure by a process which yields a. yellow dyestuff from the dyestufi forming substance present in layer l and a magenta dyestufi from the dyestuff forming substance present in layer 2. After all of the three layers are diffusely dyed and the silver images are developed, three part images formed by black silver are present, each in one of the three layers. The color selection picture which has been obtained by the photographic action of blue light is obtained in the layer diffusely dyed yellow, the color selection picture obtained by the green light rays is present in the layer diffusely dyed by the magenta dyestufi and the red color selection picture is situated in the blue-green dyed layer.

The dyestufi in each of the three layers is, thereafter, locally destroyed at the points where 5 silver is present. Thus a multicolor image composed of three superimposed differently colored part images and giving the correct colors of the object photographed is directly obtained in the recording material.

The light sensitive material and the process described are especially adapted for the use of the amateur, because color pictures in the cor rect colors are directly obtained from the exposed recording material by appropriate treatment. With most of the present materials and processes it is-either necessaryin order to obtain a correct color imageto make a second print from the image originally obtained which is a negative, or to develop the exposed plate or film by a reversal process to form a positive.

A further advantage of the new recording material results from the fact that the three layers are arranged on that side of the transparent support which is remote from the light source or objective during exposure. Disturbing halation effects are thereby avoided.

The arrangement of the three layers of the new material in which the red sensitive layer is not coated next to the support, but is arranged on top of the two other layers offers a number of advantages. The quality of a multicolor image depends to a great extent upon the correctness of the blue-green part image. This part image is produced in the top layer of the recording material. As the dyestuff is applied to this layer after exposure, this material ofiers the advantages that the color intensity of this layer can easily be corrected by the coloring process and an exact balance between the blue-green dyestuff 40 and the dyestufis produced from the dyestuff forming substances present in'layers l and 2 can be obtained without diificulty.

The dyestufi forming substances incorporated in layers l and 2 are selected in such way that azodyestuffs of the required color shade can be simultaneously produced. Either substances which are capable of coupling with a diazocompound may be used, or amino-compounds which are capable of being diazotized and to yield azodyestuffs by coupling.

An exposure material which is to be regarded as an example only of my invention, may be produced as follows. A transparent support such as glass, Celluloid or cellulose acetate is coated with an ordinary silver halide emulsion of high sensitivity for blue light. An emulsion may be used which contains about 14 grams gelatine per square meter of the coating and about 12 to 14 grams silver bromide. Before coating an alcoholic solution containing 0.85 g. per sq. meter (grams per square meter) emulsion, 1-phenyl-3- methylpyrazolonisadded to the emulsion or a derivative therefrom may be used, for instance, the triphenylguanidine-salt of the dipyrazolone obtained from p-aminobenzoyl-p-phenylenediamine-sulphonic acid, according to Chemisches Zentralblatt, 1916, Vol. I, page 196. On top of the blue sensitive layer a second layer is coated formed by a silver halide emulsion sensitized by 2 methyl 1 ethylthiopseudocyanine-iodide (Journal of London Chem. Soc. 1928, Vol. 1, page 214) and containing 1 g. 1-amino-8-naphthol- 3,6-disulphonic acid or preferably a derivative therefrom such as carbonyl-ibis- 8-[4-(4-amino-benzamino) benzamino] -naphthol-(1)-disulphonic acid (3 '6) (Bellsteins Handbuch der organischen Ghemie, 4th ed. 1933', Suppl. Vol. XIV, page 759, formula XI on page 758), calculated per sq. m. of the coating. The sulphonic acid may be rendered insoluble within the emulsion by the addition of a precipitating agent such as, for example, triphenylguanidine-acetate. The emulsion is dyed yellow by the addition of 0.75 g. per sq. m. of Tartrazine (Colour Index No. 640). On the top of the second layer a silver halide emulsion layer is coated which is sensitized to red, for example by Pinacyanole. This layer contains 1 g. diphenyl-guanidine acetate per sq. m. emulsion and may be colored red by a red filter dye. After exposure in the camera the film or plate is developedby a weakly alkaline developer. As an example of a suitable developer the following may be mentioned:

The film or'plate is treated with this developer for about 20 to 25 minutes and, thereafter, fixed and washed. Thereafter, the film or plate is treated by a solution containing'a diazonium salt solution such as, for example Diazosulfanilic acid g 0.5 Sodium acetate g Water g 100 The temperature of the bath may be chosen between 3 and 8 C. and should not be higher than about 10 C. The coupling is accomplished after 5 minutes. The treatment results in the formation of yellow dyestuff and a red dyestuff in the two layers I and 2. After a few minutes the film is washed and dried. The dry film is treated by a blue-green dyestufi solution, for example by a 3% solution of Pontamine Sky Blue (Colour Index No. 518) which is precipitated in the form of its diphenyl-guanidine-salt. After 4 to 6 minutes the intensity of the colorization may be tested and the coloring process is interrupted as soon as the film as a whole appears in a black or grey color. After a short treatment with water the film is hardened by a 10% solution of chromium alum and then the dyestuff is destroyed at the silver points of all the layersfby acid solution of thiocarbamide containing for example Thiocarbamide g-.. 3.5 Sulfuric acid conc ccm 0.5 Water ccm 100 After about 10 to 20 minutes the film or plate is removed from the dyestufi destroying bath and the silver is bleached out by cupric chloride to form silver chloride which is dissolved by sodium thiosulfate. V The film is washed and dried.

Instead of the thiocarbamide solution any suitable dye-destroying agents can be used such as, for instance those described in my U. S. Patent No. 2,020,775, Nov. 12, 1935.

Instead of diffusely dyeing the top layer and thereafter destroying the dyestufi locally any other suitable method for producing a colored image may be applied to the top layer.

Instead of the dyestuif forming substances used in the example, other dyestufi forming substances may be used including stable diazo-compounds, phenols, naphthols, aromatic amines, hydrazo-compounds, as for instance described in my prior U. S. Patents Nos. 2,071,688, Feb. 3, 1937, 2,041,827, May 26, 1936, and 1,956,017, April 24, 1934. Furthermore, other filter dyestuffs orv other sensitisers may be applied as is well known in the art. Between the single light sensitive layers there may be applied layers of plain gelatine either colorless or containing filter dyestuffs.

The material described in the present specification is especially adapted for the process described in my U. S. Patent No. 2,071,688 but the dyestufi forming substances described in my U. S. Patent No. 2,041,827 may be used instead of the dyestufi forming substances described in my U. S. Patent No. 2,071,688. a

Furthermore, amino-compounds capable of being diazotized can be used within the three layers of the material, such as for example 0.85 g. Diazo-Light-Yellow 2 G (Colour Index No. 654), may be present in the blue sensitive layer, whereas in the second layer the urea obtained from 1-5-naphthylene-diamine may be used, the

third layer in this case being the same as the third layer of the foregoing example. This third layer, however, may also be applied without addition of a precipitating agent. After exposure the three layer material is developed as described above. Thereafter the film or plate is treated by a solution containing Sodium nitrite; g 1

Sulfuric acid conc ccm 16 Water F liter 1 The temperature of the bath may be chosen between 3 and 8 C. and should not be higher than about 10' C. The diazotation is accomplished after 10 to 15 minutes. The film is washed and may be treated for a short time in a 3% solution of urea. The film or plate, thereafter, is treated with a 2% solution of fi-naphthol dissolved in alkali, the solution being as far as possible neutralized by the addition of acetic acid. The treatment results in the formation of yellow dyestuif and a red dyestufi in the two layers I and 2.

Instead of difiusely dyeing the top layer and thereafter destroying the dyestuff locally any 'other suitable method for producing a colored image may be applied to the top layer.

What I claim is: I 1. A light sensitive multi-layer photographic material adapted to be exposed through a transparent support and having three light sensitive silver halide emulsion layers applied in superposition on the same side of the support, only two of the three layers comprising a dyestuif forming substance for the formation of azodyes, the light sensitive layer next to the support being predominantly sensitive to blue light, the layer between the blue sensitive layer and the third layer being predominantly sensitive to green light and the layer on the surface of the assembled multi-layer material being predominantly sensitive to red light, a dyestufi forming substance in the blue sensitive layer capable of forming a yellow azo-dyestufi, a dyestuff forming substance in the green sensitive layer capable of forming a magenta azo-dyestuff, and means for preventing exposure of said red and green sensitive layers by blue light through said support.

2. A light sensitive multi-layer photographic material adapted to, be exposed through a transparent support and having three light sensitive silver halide emulsion layers applied in superposition on the same side of the support, only two of the three layers comprising a dyestuff forming substance for the formation of azo-dyes, the light sensitive layer next to the support being predominantly sensitive to blue light, the layer between the blue sensitive layer and the third layer being predominantly sensitive to green light and the layer on the surface of the assembled multi-layer material being predominantly sensitive to red light, a dyestufi forming substance in the blue sensitive layer capable of forming a yellow azo-dyestuff, a dyestuff forming substance in the green sensitive layer capable of /-forming a. magenta azo-dyestuff, and a yellow filter dyestuif in said green sensitive layer for preventing exposure of said red and green sensi- 40 tive layers by blue light through said support.

3. A light sensitive multi-layer photographic material adapted to be exposed through a transparent support and having three light sensitive silver halide emulsion layers applied in superposition on the same side of the support, only two of the three layers comprising a dyestufl forming substance for the formation of azo-dyes, the light sensitive layer next to the support being "predominantly sensitive to blue light, the layer between the blue sensitive layer and the third layer being predominantly sensitive to green light and the layer on the surface of the assembled multi-layer material being predominantly sensitive to red light, a dyestuff forming substance in the blue sensitive layer capable of forming a yellow azo-dyestufi, a dyestufi forming substance in the green sensitive layer capable of forming a magenta azo-dyestufl, means for preventing exposure of said red and green sensitive layers by blue light through said support, and a red filter ,dyestuff in said red sensitive layer for preventing exposure of said red sensitive layer by green light through said support.

4. A light sensitive multi-layer photographic material adapted to beexposed through a transparent support and having three light sensitive silver halide em sion layers applied in superposition on the same side of the support, only two of the three layers comprising a dyestuif forming susbtance for the formation of azo-dyes, the light sensitive layer next to the support being predominantly sensitive to blue light, the layer between the blue sensitive layer and the third \layer being predominantly sensitive to green light and the layer on the surface of the as sembled multi-layer material being predominantly sensitive, to red light, a precipitating agent capable of forming an insoluble salt with a blue green dyestuff in said red sensitive layer, a dyestufl' forming substance in the blue sensitive layer capable of forming a yellow azo-dyestufi,

a dyestufi forming substance in the green sensitive layer capable of forming a magenta azodyestufi, and means for preventing exposure of said red and green sensitive layers by blue light through said support.

5. A light sensitive multi-layer photographic material adapted to be exposed through a transparent support and having three light sensitive silver halide emulsion layers applied in superposition on the same side of the support, only two of the three layers comprising a dyestuii forming substance for the formation of azo-dyes, the light sensitive layer next to the support being predominantly sensitive to blue light, the layer between the blue sensitive layer and the third layer being predominantly sensitive to green light and the layer on the surface of the assembled multi-layer material being predominantly sensitive to red light, a substance in the blue sensitive layer capable of being transformed into a yellow azo-dyestuff by coupling with a diazo solution, a substance in the green sensitive layer capable of being transformed into a magenta azo dyestufi by coupling with the same diazo solution, and means for preventing exposure of said red and green sensitive layers by blue light through said support.

6. A light sensitive multi-layer photographic material adapted to be exposed through a transparent support and having three light sensitive silver halide emulsion layers applied in superposition on the same side of the support, only two of the three layers comprising a dyestuif forming substance for the formation of azo-dyes, the light sensitive layer next to the support being predominantly sensitive to blue light, the layer between the blue sensitive layer and the third layer being predominantly sensitive to green light and the layer on the surface of the assembled multilayer material being predominantly sensitive to red light, an amino-compound in the blue sensitive layer capable of beingdiazotized to yield a diazo compound which will form a yellow dyestuif with an azo dye coupler, an amino-compound in the green sensitive layer capable of being diazotized to form a diazo compound capable 'of yielding a magenta dyestufi by coupling with the same azo dye coupler, and means for preventing exposure of said red and green sensitive v layers by blue light through said support.

'7. A process of producing multi-coior images which comprises exposing a photographic material having three light sensitive silver halide emulsion layers applied in superposition on the same side of a transparent support through said support, only two of the three layers comprising a dyestuif forming substance for the formation of azo dyes, the light sensitive layer next to the support being predominantly sensitive to blue light, the layer between the blue sensitive layer and the third layer being predominantly sensitive to green light and the layer on the surface of the assembled multi-layer material being predominantly sensitive to red light, a dyestufi forming substance in the blue sensitive layer capable of forming a yellow azo dyestuiI, a dyestuil' forming substance in the green sensitive layer capable of forming a magneta azo-dyestuif, said material including a filter dyestuflf for preventing exposme of said red and green sensitive layers by blue light through said support, developing the latent images, transforming the dyestuif forming substance into azo (lyestufis, dyeing the top layer of the material with a blue green dyestufi and thereafter discharging the dyestufis at the points where silver is present.

8. The process of producing multi-color images which comprises exposing a photographic material having three light sensitive silver halide emulsion layers applied in superposition on the same side of a transparent support through said support, only two of the three layers comprising a dyestufi forming substance for the formation of azo dyes, the light sensitive layer next to the support being predominantly sensitive to blue light, the layer between the blue sensitive layer and the third layer being predominantly sensitive to green light and the layer on the suriaoe oi the assemhled multi-layer material heing predominantly sensitive to reel light an areaozo amino-compound in the blue sensitive layer capable ofbeing (iiazotized to form a diazo compound which may be coupled with an aao coupier to form a yellow azo dye, an amino-compound in the green sensitive layer capable of being diazotizeol to form a diazo compound which may be coupled with the same azo coupler to form a magenta azo dye, saiol material including a filter dyestufi ior preventing exposure of said red and. green sensitive layers by blue light through said support, developing the latent images, treating with a diazotizing solution to transform said amino-compounds to diazo compounds, treating the material with a solution of an azo coupler to produce azo dyestufiis in saiol' Ernie (unseen.

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