US2219305A - Photographic multilayer material for color photographic purposes - Google Patents

Description

Oct. 29, 1940. l B. GAsPA u 2,219,305

Pnroennmc summum MATERIAL Fon coLoR PaoToenArnrc PunPosEs Filed Deo. s, 19:59

auf www1/Paw MGM/W arm (Titou-neg Patented Oct. 29, 1940 i UNITED STATES PATENT vori-*lcs PHOTOGRAPHIC MULTILAYER MATERIAL FOR COLGR PHOTOGRAPHIO PURPOSES Bla Gspr, Hollywood, Calif.

Application December 3, 1938, Serial No. 243,889 In Great Britain December 9, 193'] 5 Claims.

i necessary for the formation of the final image.

As is known, such light-sensitive materials after yexposure of the light-sensitive layers, are converted into lcolored pictures by means of local removal of the dyestuif. Iftwo or more layers are arranged upon the same support, it is necessary to sensitise at least two of the layers for diierently colored light in order to produce the desired color selection picture in each individual layer with light corresponding to the sensitivity. A suitable sensitisation has been described in my United States Patent Ofiice No. 1,985,344, dated Dec. 25, 1934. In the case of a printing material with al transparent support and withfcolored layers arranged on one or both sides thereof, as used for the production of color iilms or transparencies, the rst and the rear layer can'be printed if desired from each side respectively. In this case these two layers may have the same sensitivityv while the colored layer lying between acts optically as a screen. Thus, for example, in my United States Patent 2,183,393, Dec. 12, 1939 describing a three-layer iilm, an intensively colored yellow emulsion layer lies between two blue-sensitive layers ofv which the one is, colored purple-red m and the other blue-green, the yellow dyestuff serving for the composition of the image and acting a,s a filter during the printing operation.

-Now it has been found that it is not possible in all cases to limit the exposure of a blue-sensitive B5 layer or, in the case above referred to, of vthe two blue-sensitive layers, to these layers. Sometimes the yellow-colored silver halide layer behind the blue-sensitive layer or* the middle layer in the above mentioned example is also influ- Io enced by the light used for the exposure of the 50 red by -a panchromatic sensitizer which imparts a outer layers. The same phenomenon appears not only in the'example described of a yellow layer, but also can be observed, if green light falls upon a purple-colored layer, containing a sensitizer which renders lt sensitive for green light as, for example, the middle layer of the material shown in Figure 1 of my United States Patent No. 1,985,344, if this layer be rendered sensitive to sensitivity to green light in addition to the sensitivity tored light. This undesired exposure results .in a small defect of the prints, hardly visible during projection, but undesirable in viewof the 55 modern requirements and disadvantageous in certain cases as, for example, in the copying of such a picture.

It has been found that the yphenomenon described above can be suppressed by increasing the concentration of the dye to such an extent thatv the layer is more effectively screened against the action of light complementary to the color of the layer. The concentration required for eiectively shielding the layer is, howeveiylhigher than that required for correct color reproduction. Thus, the problem is not only the increase in dyestuff concentration but further the surplus of the dye must be removed during the process -and preferably without an increase of the treatment time.

'Ihe subjectof the present invention is a material having a suiiiciently high concentrl'ation of dye for the color separation and allowing a quick processing of the material.

For this purpose the layers are dyed to a color intensity higher than required by the most intensely colored parts 'of the nal image and, therefore, suiiiciently high for the color separation. Two dyestuifs of very different resistance against the treating solutions are used for this purpose. The image is formed substantially by one of these dyes alone, the other dyestu lbeing ytotally removed from the image.-

Accordingly, the invention consists of a lightsensitive :multilayer silver halide material, in which at least one light-sensitive layer is formed by an emulsion which in its uncolored state would be sensitive not only to. light for which the layer is predominantly sensitised and to which it is intended to be exposed but also to light for which a. superimposed light-sensitive layer is sensitive or f to be exposed. According to the invention the layer is dyed by a mixture of the dyestuff intended to form the nal image inthe layer and a second dyestuii' of similar color. The dyestuff used for the formation of the dyestui image 'is fast to ordinary photographic treating solutions and capable of being bleached out under the influence of the silver image. This dyestu' is used in a concentration which corresponds to the color intensity necessary for a reproduction of .the :most .intensely colored parts of the picture. The auxiliary dyestuff is of practically the same color but of much larger bleaching capacity than the dy'estuff for the formation of the image and can be totally removed by treating solutions harmless .to the image forming dyestuff. The quantity of the auxiliary dyestuif is chosen in such a manner that its absorption in addition to that of the image forming dyestuif is practically suiiicie'nt fOr preventing any light of complementarycolor to enter the layer. This image forming dycstu may be bleached locally preferably prior to but also during or subsequent to the removal or destruction of the auxiliary dyestuff and the destruction has the effect of lowering the color intensity to that required for a reproduction of the most intensely colored parts of the picture.

Example 1 As shown in Fig. I of the drawing a silver halide emulsion layer sensitised to green or red light and dyed by a mixture of the dyestuff Xylenewalkgelb (Sandoz, Handbuch der Faerberei, 1926, 2nd ed.) and the auxiliary dyestuff 4,4methenyl bis- [1-(p-sulphophenyl) -3-methyl-pyrazolone-5l is arranged between a blue-sensitive silver halide emulsion dyed magenta by the N-methyl-naphtho-quinolinium salt of the dyestuff Tuchechtbrillantrot 2B, and a blue-sensitive silver halide layer surface N-methyl-naphtho-quinolinium salt of the dyestuff Tuchechtbrillantrot 2B 1.2

Triphenyl-guanidine salt of 4,4'methenyl bis- 1 p sulphophenyl) --methyl-pyrazolone-5]; 1 Calcium salt of Xylenewalkgelb G 1.4 Pontamine Sky Blue 5BX 0.6

The material may be used for the production of dyestuff images in the manner described in my aforementioned Patent 2,183,393. The dyestuff 4.4methenylbis[1(p-sulphophenyl) -S-methylpyrazolone-5] and its preparation is described in my application Ser. No. 240,860 led Nov. 16, 1938. The dyestuff is decolorised by an alkaline developer or by solutions containing sulphite or bisulphite compounds.

Example 2 In Fig. II I have shown that the support which in this case can be opaque, carries a silver halide layer which is colored blue-green with the N- methyl-naphtho-quinolinium salt of the dyestuff Ponta'mine Sky Blue 5BX and sensitised with cryptocyanine for infra-red light. This layerl contains further a destructible blue-green dyestui, viz., the dyestuff obtained from l-(p-sulphophenyl)3methylpyrazolone5 and glutaconic-dialdehyde-dianilide. Instead of being incorporated within the layer4 the dyestuff may be applied by the aid of a thin gelatin layer containing the auxiliary dyestuil' in a concentration of 0.5 g. per sq. m. the gelatin being poured upon the rst layer. A silver halide emulsion layer, sensitised to red light by pinacyanole, and colored magenta with the N-methyl-naphtho-quinoy linium salt of Tuchechtbrillantrot 2B, is etiher coated directly on the blue-green layer or layers or on an intermediary layer of colorless gelatin.

VThe magenta layer, its surface or a separate layer lying above contains a red dyestuff which may be, for example, the diphenyl-guanidine salt of the sulphonnic acid derived from methenyl-bis-oxythionaphthene which may bev prepared by adding di-phenyl guanidine, dissolved ln water with 1511 addition of acetic acid, to the dyestuff solution. A yellow colored silver halide emulsion as described in Example 1 is sensitised to green and used in front of the other layers.

The quantity of dyestuff depends upon the use of the material. In the case of an image on a transparent support for projection or for transparencies, the dyestui concentrations may be the same as given in Example 1, whereas in a material for the production of colored images on a paper support the concentration of the imageforming dyestuii is decreased toabout 1/2 or 1/3 of the amounts given in Example 1, whereas the concentration of the auxiliary dyestuff is increased correspondingly.

As already described in connection with Example 2 the auxiliary dyestuff having the same or similar color as the image-forming dyestuff may be incorporated in an additional or intermediate layer arranged in front of the light-sensitive layer colored with the image-forming dyestuff. The auxiliary layer may also be light-sensitive and in this case should be sensitised for a spectral range which allows a separate exposure of the intermediate layer as described in my copending application Ser. No. 243,886, led Dec. 3, 1938. In this case the auxiliary dyestuff may be destroyed, after diffuse illumination of the intermediate layer and developing, by the dyestuff destroying agent which locally destroys the dyestuffs within the image-bearing layers, such as, for instance, 5% hydrobromic acid or an acid thiocarbamide solution.

What is claimed is:

1. Light-sensitive multilayer material comprising a plurality of silver halide emulsion layers dyed with fast dyes necessary for the formation of a multicolor picture, at least one of which is formed by an emulsion which in its uncolored state would be sensitive not only to the light for which the layer is predominantly sensitized and to which it is to be exposed but also to a dierently colored light to be used for the exposure of another of said fast dyed light-sensitive layers situated in front thereof, said other layer being both predominantly sensitive to and at least partially transparent to such differently colored light, the fast dyestuff in the layer first referred to being a dyestuff which absorbs said differently colored light transmitted by the superposed layer and being fast to ordinary photographic treating solutions and being capable of being bleached under the influence of the silver image, the dyestuff further being present in a concentration which is necessary for the, reproduction of the most intensely colored parts of thev picture, a layer of the multilayer material behind said other layer containing additional dyestuff of substantially the same color as the first-named dyestuff but removable by an agent which does' not remove the mst-named dyestuff, the amount of fast dyestun' and additional dyestuff together being sumcient to prevent any light of complementary color from entering the said first referred to fast-dyed light-sensitive layer.

2. Light-sensitive multilayer material comprising a plurality of silver halide emulsion layers dyed with fast dyes necessary for the formation of a multicolor picture, at least one of which is formed by an emulsion which in its unoolored state would be sensitive not only to the light for which the layer is predominantly sensitized and to which it is to be exposed but also to a dierently colored light to be used for the exposure of another of said fast dyed light-sensitive layers situated in front thereof, said other layer being at least partially transparent to such differently colored light, the fast dyestuf in the layer rst referred to being a dyestuif which absorbs light rays transmitted by the superposed layer and being fast to ordinary photographic .named dyestuif, the amount of fast dyestuff and additional dyestufl together being suflicient to prevent any light of complementary color from entering the said first referred to fast-dyed lightsensitive layer. I y 3. Light-sensitive multilayer material comprising a plurality of silver halide emulsion layers dyed with fast dyes necessary for the formation of, a multicolor picture, at least one of which is formed by an emulsion which in its uncolored state would be sensitive not only to the light for which the layer is predominantly sensitized and to which it is to be exposed but also to a differently colored light to be used for the exposure of another of sa'id fast dyed light-sen- A sitive layers situated in front thereof, said other layer being at least partially transparent to such differently colored light, the fast dyestuli` in the layer rst referred to being a dyestui which absorbs light rays transmitted by the superposed layer and being fast to ordinary photographic treating solutions and being capable of being bleached under the influence of the silver image, the dyestuff further being present in av concentration which is necessary for the reproduction of the most intensely colored parts of the picture,'an intermediate layer between the layer first referred to and thesaid other layer situated in front thereof containing an additional dyestui of substantially the same color as the first-named dyestuff but removable byv an agent which does not remove the'flrst-named dyestuff, the amount of fast dyestuff and additional dyestuff together being sufficient to prevent any light` of complementary color from entering the said `first referred to fast-dyed light-sensitive layer.

4. A light-sensitive multilayer material -comprising a plurality of silver halide emulsion layers, at least one of which is formed by a dyed emulsion which in its uncolored state would be sensitive not only to the light for which th layer is predominantly sensitized and to which it is to be exposed but also to a differently colored light to be used for the exposure of another light-sensitive llayer situated in front thereof, said other layer being at least partially transparent to such differently colored light, the layer flrst referred to being colored with a dyestuff which absorbs said differently colored light transmitted by said other layer, said dyestuf being fast to ordinary photographic treating solutions and being capable of being bleached under the influence of the silver image, said dyestuif further being present in a concentration which 'is neces- Sary Afor the reproduction of the most intensely colored parts of the picture, a layer of the multilayer material behind said other layer contain, ing an additional dyestuff of substantially the same color as the first-named dyestuif but removable by an agent which does not remove said first-named dyestuff, the amount of fast dyestuif and additional dyestuff together being sufflcient to prevent any of said differently colored light from entering the said rst referred to light-sensitive layer.

5. A lightsensitive multilayer material comprising a plurality of silver halide emulsion layers, at least one of which is formed by a dyed emulsion which in its uncolored state would be sensitive not only to the light for which the layer is predominantly sensitized and to which it is to be exposed but also to a differently colored light to be used for the exposure of another light` sensitive layer situated in front thereof, said other layer being atleast partially transparent to such differently colored light, the layer first referred to being colored with a dyestuff which absorbs said differently colored light transmitted by said other layer, said dyestui being fast to ordinary photographic treating solutions and being capable of being bleached under the influence of the silver image, said dyestui further being present in a concentration which is necessary for the reproduction of the most intensely colored parts of the picture, the layer first referred to containing an additional dyestuff of substantially the same color as the first-named dyestuif but removable by an agentwhich does not remove the first-named dyestuff, the amount of fastdyestuff and additional dyestuff together being sufficient to prevent any of s aid differently colored light from entering the said flrst referred to light-sensitive layer.

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