DE319459C - Photographic material - Google Patents

Description

Photographic 1 material. The invention aims to manufacture a photographic material which is highly photosensitive can be and is transparent. This is achieved in that compared to a ordinary silver bromide plate increases the amount of gelatin to an extraordinarily high degree and the amount of silver bromide is reduced considerably.

In a laboratory experiment one can proceed in such a way that one For example, a 9 X 12 cm silver bromide gelatin plate is placed in water so that the gelatin softens, whereupon the emulsion is scraped off and melted in a water bath - This small amount of emulsion adds 40 cc of 6 percent gelatin solution et #% va 40 to 50 ° C added, after which the whole thing is mixed well and shaken. With a thin layer of watering, ao to 3o plates g X 12 cm with the emulsion of this can now a plate can be produced which has the required sensitivity, while they are completely transparent, even when several such plates are placed on top of one another will.

When photographing on such a plate, after development and fixation obtained a negative which is extremely dull and suitable for ordinary copying is completely useless. One can, however, make a useful one out of such a negative Produce copy material by, for example, these plates by means of known method reinforced and thereby achieved a better coverage. One by far Better results are obtained when the silver is absorbed into a dye Converts compound and then colors the image with suitable dyes. A Such dye-absorbing material is, as is known, iodized silver; it has but it has been shown that silver rhodanide and colorless cupro salts (cuproiodide and cuprorhodanide) are suitable for this purpose. - As examples, some recipes are intended for making it be cited by brightly colored pictures from such a dull silver picture.

44 ccm 10 percent potassium citrate solution, 15 ccm 2 percent cupric sulphate solution, 15 cc of 10 percent potassium rhodanide solution, cc of acetic acid.

After bleaching in this solution, the plate is washed out and then in basic dyes or certain acid dyes (acid rhodamine real green etc.) colored, whereupon it is rinsed again until the dye is not bound is washed out.

The plate can also be bleached in a known manner with cupric sulphate and potassium bromide, whereby the silver is replaced by silver bromide and cuprobromide. These compounds are not strongly dye-absorbing, but if you use this plate according to 1; ; p t_ the .following solution treated: ` 30 cci: water, - = '2o ccm io percent potassium citrate solution, 2o ccm 2o percent potassium iodide solution, in which at the same time some dye, for example rhodamine, is dissolved, the plate is gradually cleared, and at the same time the Dye bound to those places where silver bromide and cuprobromide used to be.

In the recipe above, the potassium citrate can be replaced by other substances that have a hardening effect on the gelatin.

The above-mentioned plate with silver bromide and cuprobromide or optionally a plate with silver bromide alone can also be treated with a solution, which contains sulpholic acid (thiocarbamide) as an essential component, the dye-absorbing one Substances generated. One can, for example, dissolve cuproiodide in thiocarbamide dissolvingly and treat the plate with this solution, or you can use the following recipe, which is particularly suitable if the pellicle is silver bromide or another silver halide contains.

75 cc water, 25 cc 5 percent potassium metabisulphite solution, 25 cc 4% thiocarbamide solution, 10 ccm 2% potassium iodide solution, 25 ccm 10% Potassium rhodanide solution.

After treatment with one of the above-mentioned thiocarbamide-containing solutions the image is colored and washed out.

In each of these ways one obtains an intensely colored picture, the can be used in the usual way for copying, or that one of the partial images can make out in three-color photography.

Since the said photographic membranes are transparent, can one, without noticeably impairing the sharpness, several such membranes when taking the picture place one on top of the other and thus get all partial images exposed at once.

In the production of two-color images using this process, the differently sensitized photographic membranes on one side each of the same carrier.

When making three-color pictures, you can use a simple membrane Pour onto celluloid, glass or the like and this with the double membrane given above fold.

Between and in front of the various membranes can optionally different light filters can be attached.

Claims (3)

PA1PENT CLAIMS: i. Photographic material obtained from one Silver halide gelatinous membranes commonly used sensitivity in which the silver halide in such a small amount relative to the amount of gelatin exists that the photographic plate or the like is transparent and the light can pass essentially without scattering. 2. Method of producing intense colored images by means of the photographic material according to claim i, characterized in that characterized in that the silver formed during development by treatment with.ein Solution of cupric salts is replaced by a colored cuprous salt, which is thereupon is colored. 3. Process for producing intensely colored images by means of of the photographic material according to claim i, characterized in that a Image made of silver or cupro halide by treatment with a thiocarbamide-containing one Solution and - subsequent coloring is converted into a colored picture.