DE661745C - Process for the production of fading layers for multicolored light prints, in particular for multicolored blueprints - Google Patents

Description

In the manufacture of fading layers

for collotype purposes, the selection or Adjustment of the dyes to achieve a uniform lead after different Principles take place:

1. Application of the sensitivity of appropriate amounts of dye, their complete Implementation at the applied concentration of the sensitizer the same time claimed.

2. Attachment of the dyes in separate and differently sensitized layers.

3. Organic-chemical intervention in the constitution of the dyes.

If you use the first option, the colors will be mainly the pure colors, mostly incorrect. The use of the second option is complicated the manufacturing process and is uneconomical

ao borrowed. The third method is only applicable to a limited number of dye groups. The last two types of execution include a subsequent Vex improvement of the ready-to-use photosensitive Mix of. As a fourth possibility it should be mentioned that one can choose from the large number of dyes and sensitizers put together a suitable layer after a series of tests. All of these procedures limit the number of applicable dyes or prevent the use of valuable representatives of certain Dye classes and the combination of these with each other or with representatives of others Classes and make it difficult to use a single sensitizer.

In the course of the development of the present invention it was found that the Change in the concentration of the sensitizer in a fading layer with solid Dye concentration ratio certain regular changes in the properties of the Shift. It was further found that this law not only for the exact selection and coordination of one with consideration for the other important ones Claims compiled layer is suitable, but also the application of allows previously unusable dye combinations. The vote takes place as follows: The fading mixture is made up of the dyes, and samples of the same amount are taken therefrom. Different parts by weight of the sensitizer are added to each sample added. Of course only one can

Sensitizer can be selected that has a sensitizing effect on each of the dyes. Now a diagram is made with - yy a curve for each dye. The Sensitizer quantities recorded, on the other hand either the time in which a A certain degree of fading is to be achieved, or the degree of fading achieved in a certain Time. (The degree of fading is measured e.g. with the Zeiß-Pulfrich step photometer measured as quotient, change in whiteness, greatest possible change in whiteness. When displaying the time, it is advantageous to choose a fixed degree of fading of 50%.) As the amount of sensitizer increases, there is either a first drop on the curves and thereupon the setting of an equilibrium be perceptible or first one Decrease and then an increase (similar to the well-known inhibition of oxygen in oxidation reactions), provided that you have the time or half-life as a function of the sensi-

"has shown the bilizer concentration. If one goes far enough into the context with If you follow the addition of increasing amounts of sensitizer, you will see an area on the diagram in which the various curves very closely approach or intersect. Mixtures of sensitizers with a fixed mixing ratio behave like a single sensitizer. To the center of the greatest Approach or the intersection area belongs to the coordinate of the most favorable concentration of the sensitizer, which for practical purposes has a parallelism of the Curve, degree of fading according to the exposure time (or exposure intensity, amount of light) secures.

Example tind Fig. 1

% Anethole

S 10

Dyes:

a) erythrosine (tetraiodofluorescein),

b) auramine,

c) methylene blue. .

Sensitizer:
Anethole.

Example and Fig. 2

1 line

Dyes:

a) erythrosine (tetraiodofluorescein),

b) fluorescein,

c) Victoriablaii (triammodiphenylnaphthylmethane).

Sensitizer:
Allyl thiourea.

Figs. 1 and 2 show the half-life (Ordinate) as the function of the sensitizer concentration (abscissa). The dotted one Circle means the area of the best concentration of sensitizers.

If one applies the found sensitizer concentration on, the bleaching takes place practically synchronously (after a certain Amount of light worked). This is readily apparent from Fig. 3, which shows the degree of fading in percent (ordinate) as a function the exposure time (abscissa).

■ \ 100%

SD%

Example and Fig. 3

60 100

Dyes of Fig. 1,
Sensitizer concentration: 3% anethole.

Suitable sensitizer concentrations can be found in Figs. 1 and 2. If you z. For example, if the sensitizer concentration in Fig. 1 is increased by 1%, the ordinate value for the erythrosine _{curve changes by about 30 ° / 0} , while there is almost no change in the other two curves. In practice it is generally advisable to maintain the concentration value found for the sensitizer with an accuracy of + 15%.

According to the example and Fig. 2, the following emulsion is used: 200 parts of Weicl

gelatine, iooo parts hot water. After the swelling has taken place, it is used as a sensitizer Add 30 parts of allyl thiourea and a solution of 5 parts of erythrosine, 12 parts Fluorescein and 8 parts Victoria Blue in 1000 parts of water.

Would you z. B. add only 20 parts of allyl thiourea, the blue dye would disappear prematurely and the copy takes on a predominantly orange color. If, on the other hand, you have 40 parts of allylthione urea would use, an undesirable shade of violet would appear because of the premature disappearance of the yellow dye enter.

Following the voting method described above, the use of new dyes and dye combinations not previously used for fading layers checked. It was found that quinone imine dyes are generally related to one another can be tuned and that also the sensitization of bromide silver layers already known dyes that are between two groups, such as indole and benzothiazoline, contain a methyne chain (carbocyanines), use for fading layers and with quinonimine and other dyes let combine. As a result, it is now possible to use the group of quinone imine dyes, the more or less satisfactory one already known for some fade layers Combinations resulted in (flavindulin-capri blue-rosindulin combination, Combination of substituted flavindulins), better to use and new cheap dye combinations to build.

One uses z. B. the following mixture: 5 parts Safranin GG (Geigy), 50 parts flavindulin (Phenanthrene phenylphenazonium chloride), 8 parts io-bromo-i: 1 ': 3: 3: 3': 3'-hexamethylindodicarbocyanine bromide (herge

constitutes from 1: 2: 3: 3-tetramethylindolenine bromide and a ~ bromo - /? - anilinacraldehyde anil.), 150 parts of allylthiourea, 3000 parts of 45% strength aqueous gelatin solution. After complete Dissolution, 20 parts of dimethylallylthiourea in a little alcohol are added as a sensitizer. By low Changes in the concentration of the sensitizer solution can lead to minor errors, which could possibly cause asynchrony, compensate.

Claims (2)

Patent claims: ι. Process for the production of fading layers for multicolored light prints, in particular for multicolored light pauses, characterized in that after mixing the dyes in optically favorable proportions with one another the coordination to achieve an almost simultaneous bleaching of all individual dyes of the dye mixture by adding such an amount of sensitizer as can be derived from a combination diagram Fading sensitizer diagrams of the individual dyes to be mixed with one another is determined in which the degree of fading or the time to achieve the same degree of fading as a function of the concentration of the amount of sensitizer or a sensitizer is shown, with manufacturing defects possibly subsequently due to minor changes in the concentration of sensitizers be balanced. 2. The method according to claim 1, characterized in that for the dye mixtures Dyes are used which contain a methyne chain between two groups, such as indole and benzothiazoline (Carbocyanines).