US2278984A - Method of treating color photographic materials - Google Patents

Description

April 7, 1942.

B. GAsPAR ETAL METHOD OF TREATING COLOR PHOTOGRAPHIC MATERIALS Filed March 27, 1940 I I SUPPORT BLUE SENSITIVE SILVER HALIDE YELLOW' FILTER DYE GREEN SENSITIVE SILVER HALIDE REDUCIBL RED cmmm DYE AND PANCHROMATIC SILVER HALIDE AND REDUCIBLE RED DYE SUPPORT BLUE SENSITIVE SILVER HALIDE YELLOW DYE AND CATALYST ORTHOCHROMATIC SILVER HALIDE AND YELLOW DYE SUPPORT BLUE SENSITIVE SILV AND CATALYST ER HALIDE FIG. 3.

' terial.

Patented Apr. '7, 1942 UNITED STATES PATENT OFFICE 1 METHOD or, TREATING ooLo'a PHOTOGBAPHIG MATEltIALS Bla Gaspar, Hollywood, Calif and Laszlo Schwarc. Brussels, Belgium, assignors, by direct and mosne assignments, to Chromogen, 'Incorporated,a corporation of Nevada Application March 27, 1940, Serial No. 326,270 In Great Britain March 29,1939

(]. 95- 2) x of the diiferent layers of .which and more specia; Claims.-

The present invention relates to a photographic material and to methods 'of treating the same. 7 For many photographic purposes-multilayer materials are known in which some of the layers which are to be colorless in the final multicolor picture are uniformly dyed during the manufacture or during. the treatment of the multilayer 'material and have to be decolorized by a treatfically that layer that is colored or isto be colored by a. reducible dye and that later on is to be uniformly bleached contains a'substance that is capable of accelerating the reduction of the dye by reducing agents. Suitable accelerating substances are, inter alia, phenazine compounds and quinoxaline compounds. These substances may be incorporated into a filter layer or into a lightsensitive emulsion layer and if desired they may be precipitated within the layer either by precipitating agents or by the dye itself.

The dyes used are preferably substantive and acid azo dyes.

A suitable reducing agent is a titanium trichloride solution or a diluted 'hydrosulphite solution or a solution of formaldehyde sodium sulphoxyllayer material in which at least two layers are dyed by reducible dyes, the one layer containing an addition which influences the bleaching speed of the dye to such an extent that the dye present within the said one layer can be totally bleached within a. period in'which the dye -pres-- ent within the other layer is. scarcely affected. The speed-influencing substance may be an accelerator present within the layer to be selectively bleached or a retarder present within the layer not to be bleached. An accelerator within ate (Schultz Farbstofftabellen, Leipzig 1932, 7th

chloride may also be used.

Photographic layers containing the dye and the accelerating substance are bleached in a considerably shorter time than layers without the addition. Thus, for example a gelatin layer the one layer and a retarder within the other 7 layer may also be applied. Preferably, the accelerator and/or the retarder as well as their conversion products should have a negligible tendency to wander from one layer into the other.

It is a further object of the present invention to provide a photographic material which is particularly suitable for carrying out the selective bleaching of one layer without simultaneously bleaching another layer which may contain the same or a different dye,

The invention is based partly upon the known fact that certain dyes are bleached byreducing agents only with great difllculty, but that the reaction can beaccelerated by the addition 01 catalysts to the bleaching solution. .7

Figures 1, 2 and 3 of the drawing disclose cross sectional views of materials with the layers drawn to an. enlarged scale which illustrate modifications of the improved photographic ma For carrying out the process according to the present invention a material may be used, one

hydrochloric acid containing .45% "2,3-diaminophenazine the dye will be bleached completely within 4 minutes. A gelatin layer dyed with Supranolbrillantrot 3BL or 3B (Schultz Farbstoiitabellen, Leipzig 1932, 7th ed., vol. 2, page 204) will be bleached within 3 minutes if treated in the same manner with 2,3-diaminophenazine,

whereas without such treatment the bleaching requires more than 20 minutes.

Layers containing the accelerating substance may be processed in various manners for which the following examples may be given.

Example 1 The multilayer material disclosed in Figure 1 is in the form of a bipack having two supports 1 and 2, three silver halide emulsion layers' 3, 4

- and 5 and two filter layers 6 and -l, the front for about 8 8 coated thereon. The second support 2 is coated with a panchromatic silver halide emulsion layer dyed with Supranolbrillantrot 3BL or 3B (Schultz Farbstofitabellen, l. c.), a superposed gelatin filter layer 1 equally colored red with Supranolbrillantrot 3BL or 3B and another silver halide layer 4 which is sensitive to green. The three light- sensitive layers 3, 4 and 5 are arranged between the two supports i and 2. The red dyed filter layer 1 contains 1 gram per square meter tetrabromodimethylquinoxaline obtainable by heating in glacial acetic acid 1 mol o-phenylenediamine with 1 mol sym. tetrabromodiacetyl (Keller, Berichte der Deutschen Chemischen Gesellschaft, v01. 23, p e 35, 1890). The two parts of the bipack are developed after exposure and fixed. The silver image formed in the front element may be used as a. printing proto-type or may be converted into a dye image. The rear element of the bipack is treated with a solution of 1 gram titanium-trichloride in 100 ccs. .04- normal hydrochloric acid, which acts to de- 'stroy the dye in the filter layer containing the front layer of the rear film is dyed with Chrysophenine G (Schultz Farbstoiftabellen, l. c.)"and thereafter the film" having a silver image uniformly dyed yellow in the one layer and a silverimage uniformly dyed red in the other layer, is subjected to the action of a thiocarbamide solution or other suitable treating solution such as a hydrobromic acid which bleaches the dyes locally and yields, after the removal of the silver images, a two-color-image colored magenta and yellow and which may be used as a printing proto-typ Example 2 The photographic material disclosed in Figure 2 comprises an orthochromatic silver halide emulsion layer 9 dyed with 1 gram Chrysophenine G (Schultz Farbstoiftabellen, l. c.) per square meter and a superposed filter layer III of gelatin containing 1 gram Chrysophenine G and 1 gram tetrabromo-dimethyl-quinoxaline per square meter. An uncolored blue-sensitive silver halide emulsion layer 8 is coated on top of the filter layer it. The multilayer material is exposed, developed and fixed, and the front layer 8 is colored by immersing the material in a solution of Supranolbrillantrot 3BL or 3B. This red dye colors the surface layer 8 and possibly also the filter layer. The dyeing process should be stopped before the yellow coloredsilver emulsion layer 9 is dyed. -If now the film is treated with a titanium trichloride solution as in Example 1,

the red dye that might have colored the filter layer will be destroyed. The dyes present in the two silver layers are hardly affected by this treatment. They are then locally destroyed by a solution of thiocarbamide or hydrobromic or hydrochlo'ric acid.

Example 3 for several hours.

Figure 3') may be present in the blue-sensitive layer I3. After exposure, development and fixing, and after the removal of the filter dye, the two uncolored layers are dyed with Supranolbrillantrot 3BL or 3B. Thereafter the film is treated with a reducing agent, for example with the tit'anium trichloride solution specified in Example 1, which decolorizes the upper layer without materially affecting the' lower layers. The decolorizedupper layer is thereafter recolored with a different dye, e. g., Pontamine Sky Blue 63x (Schultz Farbstofltabellen, Leipzig 1931, 7th ed., vol. I, No. 510), and the three dyes are locally destroyed at the places where silver is present by treating the material with thiocarbamide or hydrohalic acids.

It is often advisable to incorporate a precipitating agent into the layer in which the dye should not be decolorized by the treatment with the reducing agent, because it has been found that if the dye is precipitated it is more resistant to reducing agents, and thus the difference between the bleaching speeds brought about by in" corporating an accelerator into the layer to be I decolorizedcan be increased still further by the incorporation of a precipitant into the layer which should not be decolorized. A suitable precipitant for "the dye Supranolbrillantrot 3BL or 3B is, for example, the diacetate of diphenyl-4,

4'-dibiguanide of the formula Again for example a gelatin layer dyed with Pontamine Sky Blue 63X (Schultz Farbstofltabellen, Leipzig 1931, 7th edition, vol. 1, No. 510) is completely decolorized within a few seconds if treated with a normal sodium carbonate solution containing 2% sodium hydrosulphite and 25% anthraquinone-p-sulphonic acid. If, however, prior to this treatment, the layer is treated for 8 minutes with a 1% solution of the diacetate of 3, 3'-dimethy1-diphenyl-4, 4'-dibiguanide of the following formula NHrc-Nn-c-Nn- NH-C-NIFC-NH:

1%: 1h! L on IE3 IE3 there is no visible eflect in twominutes.

A gelatin layer dyed with Supranolbrillantrot 3BL or 3B is completely decolorized within 8 minutes if treated with a solution of 1% sodium hydrosulphite in .2 n-sodium carbonate. On the other hand, a prior treatment for 8 minutes in 1% ortho-tolidine-di-biguanide acetate solution results in complete decolorization being retarded What is claimed is:

1. The process of producing photographic dye images from a photographic multilayer film comprising at least two colloid layers on a single support, one of said colloid layers being uniformly dyed with a dye for the production of a dye image within said layer, said dye being destroyable with a reducing agent, another of said colloid layers being uniformly dyed with substantially the same dye, atleast the first of said layers comprising a photographic silver =image, the multilayer film further comprising a substance which is capable of influencing the bleaching speed of said reducing agent with respect to said dye and selected from' the group which consists of speed retarding agents present in the firstnamed layer and reduction catlysts present in the second-named layer, which comprises treatdye, at least the first of said layers comprising a stance which'is capable of destroying the dye by reduction in the presence of metallic silver only to produce thereby a dye image in the first layer with the aid of the silver image and removing the silver image. 7

2. The process of producing photographic multicolor dye images from a photographic multilayer film comprising at least two colloid layers on a single support, one of said colloid layers being uniformly dyed with a dye for the production of a dye image within said layer, said dye being destroyable with a reducing agent, another of said colloid layers being uniformly dyed with 4 substantially the same dye, each of said layers comprising a photographic silver image, representing difierent color aspects of a multicolor image, respectively, the multilayer film further comprising a substance which is capable of infiuencing the bleaching speed of said reducing agent with respect to said dye and selected from the group which consists of speed retarding agent present in the first-named layer and reduction catalysts present in the second-named layer, which comprises treating said two layers with said reducing agent to destroy thereby completely the dye by reduction within said second layer only, recoloring said layer with a difierent reducible dye and thereafter treating said film with the solution of a substance which is capable of destroying said dyes by reduction in the presence of metallic silver only, to produce thereby diiierently colored dye images within said layers with the aid of the silver images and removing the silver images. V

3. The process of producing photographic multicolor dye images from a photographic multilayer film comprising at least two colloid layers on a single support, one of said colloid layers being uniformly dyed with a dye for the production of a dye image within said layer, said dye being destroyable with a reducing agent, another of said colloid layers nearer the surface than said first mentioned layer being uniformly dyed with substantially the same dye, each of said layers comprising a photographic silver image representing difierent color asp ts of a multicolor image, respectively, the multilayer film further comprising a substance which is capable of influencing the bleaching speed of said reducing agent with respect to said dye and selected from the group which consists of speed retarding agents present in the first-named layer and reduction catalysts present in the second-named layer, which comprises treating at least said second layer with said reducing agent to destroy thereby completely the dye by reduction within said layer only, recoloring the layer with a different reducible dye and thereafter treating said I film withthe solution of a substance which is capable of destroying said dyes by reduction in the presence of metallic silver only, to produce thereby differently; colored dye images within said layers with the-aid of the silver images, and removing 'the silver images.

4. A photographic multilayer film comprising at least two colloid layers on a single support, one of said colloid layers being uniformly dyed with a dye for the production of a dye image within said layer, said dye being destroyable with a reducing agent, another of said colloid layers being uniformly dyed with substantially the same treating said two layers with said reducing agent photographic silver image, the multilayer film further comprising a substance which is capable of influencing the bleaching speed of said reducing agent with respect to said dye and selected from the group which consists of speed retarding agents present in the first-named layer and rea reducing agent said layer containing. further a substance which is capable of retarding the bleaching speed of said reducing agent with respect to said dye, another of said colloid layers being uniformly dyed with substantially the same dye and containing a reduction catalyst, at least the first of said layers comprising. a photographic silver image.

6. The process of producing photographic dye images from a photographic multilayer film comprising at least two colloid, layers on a single support, one of said colloid layers being uniformly dyed with a dye for the production of a dye image within said layer, said dye being destroyable with a reducing agent, another of said colloid layers being uniformly dyed with a dye which is not required for the production of a dye image within said layer and which is destroyable by said reducing agent, said last mentioned dye having approximately the same bleaching speed with respect to said reducing agent as has said first mentioned dye, at least the first of said layers comprising a photographic silver image, the'multilayer film further comprising a substance which is capable of influencing the bleaching speed of said reducing agent with respect to said dyed layers and selected fromthe group whichconsists of speed retarding'agents present in the first-named layer and reduction catalysts present in the second-named layer, which comprises to destroy thereby completely the dye-by reduction within said second layer only and thereafter treating said film with the solution of a substance which is capable of destroying the dye by reduction within said first layer in the presence of metallic silver only to produce thereby a dye image in the first layer with the aid of the silver image and removing the silver image.

7. A photographic multilayer film comprising at least two colloid layers on a single support, one of said colloid layers being uniformly dyed with a dye for the production of a dye image within said layer, said dye being destroyable with a reducing agent, another of said colloid layers being uniformly dyed with a dye which is not required for the production of a dye image within said layer and which is destroyable by said reducing agent, said last mentioned dye having approximately the same bleaching speed with respect to said reducing agent as has said first mentioned dye, at least the first of said layers comprising a photographic silver image, the multilayer film further comprising a substance which is capable of influencing the bleaching speed of, said reducing agent with respect to said dyed layers and selected from the group which consists of speed retarding agents present in the first named layer and reduction catalysts present in the second named layer.

8. A photographic multilayer film comprising at least two colloid layers on a single support,

one of said colloid layers having uniformly distributed therein a dye which is destroyable with a reducing agent said layer further containing a substance which is capable of retarding the bleaching speed of said reducing agent with respect' to said dye, another of said colloid layers being uniformly dyed with a dye which is also destroyable by said'reducing agent and which has approximately the same bleaching speed with respect to said reducing agent as has said first mentioned dye, said latter layer containing a reduction catalyst, at least the first of said layers 5 comprising a photographic silver image.

1am GAsPAR. LASZLO SCHWARC.

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