US2020607A - Photographic material - Google Patents

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PHOTOGRAPH IC MATERIAL Filed Dec. 5, 1951 Eg.; i'

`Patented Nav. 12, i935 UNITED `s'fra'rizs' PAraNrfoFl-flca I rnoroonarmc ocra umher, mamma/Anm, Germany.

alsigncrtoAgtaAnsco Corporation, Binghamton, N. Y., a corporation of New York Application December 5,1931, Serial No. 919,359 l In Germany December 6, 1930 I 1 lin superposition and dyed each to have a different color, the dyes forming constituents of the finished pictures. Reference is made to the accompanying drawing whichdllustrates two lilms according to this invention.

In color-photography and stereo-photography there are required for some purposes photographic materials which contain the dye, necessary lfor the preparation of'colored part pictures, in the emulsion' layer already before the exposure to light. When using those materials it is sometimes diicult to obtain a tintless grey scale, because the curves of gradation oi the single colored emulsion layers have not the same course. This is particularly due to the coloration of the emulsion layer which acts in such a manner that, for instance, the greenish-blue coloration of an ordinary emulsion layer permeable to blue rays alters the original gradation only to a 'relatively small extent, whereas an orange-yellow coloration which is impermeable to blue rays, similarly to the known Dup-lm, gives the colored emulsion a much ilatter gradation.

According to my present invention this difficulty is avoided by assimilating the gradation of the photographic layers used together and dyed each to have a diierent color by incorporating in at least one of these layers a filter dye which absorbs at least part of the spectral region to which the layer in question is penneable and sensitive. The concentration of the lter dyes is regulated so that the gradations of the layers are equalized. The colorations due to the iilterdyes are after exposure removed in a bath in which the photographic material is to be treated, for instance, in the developing bath, xing bath or another subsequent bath.

For equalizing, for example, red layers to green layers of a flatter gradation, for instance, methyl blue may be used.\ The coloration produced by this dye is easily removed in an aqueous solution of sodium suliite. For changing the gradation o! a blue layer. vi'or instance. tartrazine is well appropriated, .which is lremovable by washing with water. Green 'layers may be for altering the gradation additionally dyed with acidy iuchsine, the coloration produced being removable by an aqueous solution of sodium sulnte.- 'I'he 5 said removal o1 the filter dyes' usually' begins in f the usual, developing bath and is" complete in the acid fixing bath.

.The `following example will most clearly illustrate my invention without limiting it: l0

On each face of'a support a light sensitive `emulsion layer is provided, one of which is dyed with Diamine green HS (see Schultz, Farbstoitabellen 1923, vol. II page38) and the other is dyed with Salicinorange 2 R, a dye made from 15 nitrobenzidine, salicylic acid vand- 2-hydroxynaphthalene--sulfonic4 acid, and with Benzo light red 8 B L (see' Schultz, Farbstofftabellen 1923, vol. II page 19. The red dyed emulsion. which la sensitized for red is furtherm e treat- 20 ecll with methylblue which equalizes tl e'gradation of the red layer tofthat `of the green layer -wliich is sensitized for green. The proportion o f the dyes used forthe'said layer may be about the following: t 25 Parts by weight Salicinorange 2R 80 Benzo light red 8 vB L 4 l Methylblue- 0.5

' -Y 30 The concentration of the -dyes in the single layers 'is chosen in such a manner that the red layer and the green layer give together a suitable black. The gamma value of the green layer is about 0.9 and that of the red 1ayer witnot addi- 35 tion of methyl blue 1.5 to 2.v After the addition l of methyl blue the gamma value of the red lay- I er likewise is about 0.9.

In order to manufacture a three-color iilm may proceed, for instance, as follows: 40 The first emulsmn layer is colored blue green by Brilliant benzo fast green. The second emulsion layer is colored purple by Sirius red violet R (ci. Chemischcs Centralblatt 1928, vol. '1, page. 2461) or Sirius rubine B` (ci. Chemisches Cen- 45 tralblatt 1931, vol. 2, page 364). The third emulsion layerA is colored yellow by Benzo light yellow RL (ci. Fierz-David Knstliche organische Farbstoie 1926, page 168) Aor Chrysophenine G extra (ci. Schultz, Farbstotabellen 1'93l/JDC/ 50 726). In all these three layers the sensitiveness to red, green and blue light may be altered respectively -by methylv blue, acid fuchsine and tartrazine.

In the annexed drawing, Fig. 1 shows a section 55 through the support a provided on one of its faces with a light sensitive emulsion' layer b and on.,

The layer c comprises an emulsion layer dyed yellow sensitized for green andcontaining a red filter dye. The layer b comprisesan emulsion layer dyed purple sensitized for red and'contain-` ing a blue-green lter dye.l The'layer d comprises a blue sensitive emulsion layer dyed bluegreen and containing a yellow filter dye. 'I'he amount of lter dye incorporated in each emulsion layer,A is thus selectedvthat the gradations of these layers are equalized. However, the addition of filter dye to one of the emulsion layers can be dispensed withif the gradations of the reina' ing two layers are equalized tothe gradation of the emulsion layer having the flattest gradation. Y The quantity of the dye which is necessary forl the equalization of the gradations depends upon the gradation and the sensitization of the emul- 30 sion used, upon the thickness of the layer and upon the kind of development. I do not wish to limit my invention to theforegoing examples nor to the specific details given therein. Numerous other embodiments are possible and I contemplate as included within my invention all such l modifications and equivalentsias fall within the scope of the appended claims. Numerousfother Ai'llter dyes for theA purpose in question'and known ,to every chemist skilled in the art maybe 'employed. A few comparative experiments should be made to determine the most suitable lter dye and its most suitable amount to be usectl with a particularly dyed emulsion-for equalizing its gradation to that of`a differently dyed emulsion.

` What I claim is:

y 1. A photographic material comprisingA a `support, on one face of said support a light-sensitive emulsion layersensitized for green and dyed with *l Diamin Green HS and on the other face a lightsensitive emulsion layer sensitized for red and dyed with a mixture of -Salycin Orange RR and 5 Benzo light red 8 BL, the red dyed emulsion containing furthermore a substantial amount of Methyl Blue for Kequalizlng the gradationA of the red layer to that of the green layer.

2.',A photographic material comprising a sup? port and at least vtwo superimposed emulsion layers dyed to have different colors and colored for the same color to which the respective layer is specially sensitive, at least one of these emulsion layers containing furthermore a lter dye, soluble 15 l in the photographic treating baths, which absorbs at least part of the spectral region which is transmittcd by the color of this layer andto which this layer is sensitive, for equalizing the gradation of the emulsion layers.

3. A' photographic material comprising a support and at least two superimposed emulsion layers insuperpositionbeingdyed to have dierent colors and colored forth'e same color to which the respective layer is specially sensitive, at least one A'of 25 these emulsion layers containing furthermore a ,filter dye, soluble in the photographic treating baths, which absorbs atleast part of the spectral. region which is transmitted by the color of this layer and to which this layer is sensitive, for

equalizingthe gradation of the emulsion layers.

4. A photographic material comprising a support and at least two superimposed emulsion layers arranged on both faces .of the'support, said ,emulsion layers being dyed to have different colors and colored for the same color to which the respective layer is specially sensitive, at least one of these emulsion layers containing furthermore a filter dye, soluble in the photographic treating baths, which absorbs at least part of the special 40 region which is transmitted by the color of this layer and to which this layer is sensitive, for equalizing the gradation of the emulsionlayers.

GERD

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