DE122617C - - Google Patents

Description

IMPERIAL

PATENT OFFICE.

ΛΙ122617 CLASS 57d.

According to the previous methods of multi-color photography or multi-color printing the mixed colors are broken down into. individual basic colors in the photographic Recording, through optical aids, such as radiation filters, or by adding sensitizers to the photosensitive layers.

In contrast, the present invention aims to do the analysis to some extent to relocate already in the original and thereby the usual aids mentioned above to make partially or entirely dispensable. For this purpose, the original (drawing, painting, watercolor, chalk, pastel u. s. w.) resp. a copy of it only in colors of certain chemical properties executed, which the selected basic colors, z. B. yellow, red, blue, correspond, in such a way that all intermediate tones and mixed tones are produced only by mixing these colors will.

The basic colors consist of substances that can be obtained by suitable chemical means can change that for the recording of the monochrome negatives always all with the exception a single one in white or in such a color as e.g. B. blue, be transformed, which is just as effective photographically as Weifs. This leaves only one color photographically ineffective, and indeed to the same extent as they do the different Tones is mixed in. Therefore only these tones are shown on the monochrome negative (in negative drawing) and consequently on the positive produced from it (in positive drawing) while all others are black on the negative and white on the positive be reproduced.

For example, should an original be reproduced with the three primary colors yellow, red and blue the inventors first treat it in such a way that they use the yellow and the blue or just turn the yellow into white and take a photographic negative, the monochrome negative for Roth.

Then the original is subjected to a second treatment through which blue and Roth or just the Roth is transformed into Weifs, and then the monochrome negative for added the yellow color.

Finally, a third treatment turns the blue into an ineffective color, e.g. B. Black, transformed, while the other two colors are transformed into white, and now the monochrome negative for blue has been added.

From these negatives, either colored positives are made in a known manner by means of which one can reproduce the original by overlaying, or one then produces monochrome printing plates for color printing.

In the present process, if an original does not contain all of the basic colors, so The number changes accordingly

the treatments of the original as well as the negatives.

The following is used as an exemplary embodiment, in which the primary colors are yellow, red and blue The following are assumed: Mercury iodide is used as a red dye, and cyanide as yellow ferric silver and a mixture of Berlin blue and lead sulfate is used as the blue.

The colors are separately rubbed into the mold with egg white or rubber etc. brought by tablets, pens, inks and so on. The artist then paints with them by asking mixes all the nuances out of them, the original resp. a copy of what is to be reproduced Originals. After manufacture, the original is subjected to a number of washes, which in the present case are the following:

Using a solution of barium chloride, sodium chloride or any other alkali chloride the inventors make the yellow disappear, and so it remains, since it can be assumed that the blue is much the same as strongly as white acts on the plate, for photography only the red, of which now the first negative is taken.

The purpose of the second treatment is to recreate one that is similar to the original one yellow color from potassium iodide; the latter means that the red disappears at the same time. On that the second negative is taken, which is therefore only the image of the yellow parts of the original represents.

Thirdly, the inventors remove the regenerated yellow with potassium cyan, so that only blue remains, the added lead sulphate of which is then replaced by sodium sulphide (or another sulfur alkali) is converted into lead sulfur to enable a third intake will.

Composition of the colors:
Effective substances:
Roth: mercury iodide HgJ ₂ ,
Yellow: ferric cyan silver Fe ₂ Oy ₁₂ Ag ₆ ,
Blue: Prussian blue Fe ₁ Cy ₁₈ , lead sulfate Pb SO ₄₁ .

Composition of the baths:
Chlorbarium Ba Cl ₂ ,

Potassium iodine KJ, possibly to accelerate the effect with the addition of some free iodine, potassium cyanide Cy K,
Sulfur sodium Na ₂ S.

Reactions:

I. Disappearance of yellow:
Fe ₀ Cy ₁₂ Ag ₆ + 3 Ba Cl ₀ -

Fe ₂ Cy ₁₂ Ba ₃ + 6Ag Cl.

The Fe ₂ Cy ₁₂ Ba ₃ is soluble and can be removed with water, Ag Cl is white and stays on the paper.

II. A) Reproduction of the yellow:

AgCl + KJ = AgJ + KCl.
The AgJ is yellow and stays, KCl is soluble and is removed with washing.

b) Disappearance of the Roth:
Hg _{I 2} dissolves in the presence of potassium iodide and disappears on washing.

III. a) Disappearance of the yellow:

Ag J dissolves in Cy K solution and is washed out.

b) Transformation of blue containing lead sulphate into black:
'. PbSOt + Na ₂ S = z PbS + Na ₂ SO _r

The black lead sulfur formed completely covers the Berlin blue, which in the reaction doesn't matter.

To prevent the inconvenience of blackening the silver salts, as is the case with experiments has shown with older originals, use the following composition for yellow:

2 parts chlorosilver Ag Cl (white),

V ₂₀ parts of mercury chloride Hg Cl ₂ (white),

Part of the barium salt precipitated from Martius yellow (the sodium salt) with chlorobarium of dinitronaphtol (yellow).

In this case the original is first immersed in formaldehyde (CH ₂ O) in order to make the protein insoluble and to fix the colors. Then you bring the original into a solution of 5 pCt. Oxalic acid (C ₂ H ₂ OJ, until the yellow has completely disappeared. Ag Cl and Hg Cl ₂ remain unchanged.

Claims (1)

Patent claim: Process for the production of monochrome negatives for multicolor photography or multicolor photographic printing, characterized in that the original to be reproduced respectively a copy of the original is only painted with the help of colors, which changed by chemical action in such a way that one of these colors is always in proportion to the others is as ineffective as possible photographically and thus the production of the monochrome negative corresponding to this color by direct exposure.