DE806936C - Process for the preparation of color photographic images by color development - Google Patents

Description

Issued on the basis of the First Overhead Line Act of July 8, 1949

(WiGBl. P. 175)

FEDERAL REPUBLIC OF GERMANY

ISSUED JUNE 21, 1951

GERMAN PATENT OFFICE

PATENT LETTERING

CLASS 57b GROUP I812

G 345 IV a j 57b

Philibert Leopold Joseph Raymond Merckx, Mortsel, Antwerp (Belgium)

has been named as the inventor

Gevaert Photo-Producten, NV _r Mortsel, Antwerp (Belgium)

Process for the production of color photographic images

through color development

Patented in the territory of the Federal Republic of Germany from November 8, 1949

Patent granted on April 12, 1951 The priority of the application in Belgium of August 3, 1945 has been claimed

The invention relates to manufacturing photographic color images by means of color development and in particular to the use of a new group of color formers.

So far, dye formers have been used in color development are used which correspond to the following general formula:

Y-CH ₂ -CR.

In this, V denotes an electronegative group, R denotes an aryl group or a heterocyclic group substituted amino group.

It is further known as a dye-forming agent τ, 2,4-oxodiazole of the following general formula to use:

C- CH.,

X,

in which X is an electronegative organic radical, such as z.H. CN, alkyl-CO, aryl-CO, and Y. is an organic radical or hydrogen.

λ'ιιη was found that 1, 3, 4-oxo, thio or selenodiazoles are valuable dye formers.

They correspond to the following general formula:

N N

Y-C

C-CH ₂ -CN,

- C

C-CH ₉ -CN.

-0-

i, 3, 4-oxodiazolyl-2, 5-di (acetonitrile)

N N (2)

CN-CH ₂

- C

C-CH ₂ -CN.

CH, -;

> - C

-CH ₂ -CN.

These nitriles can be prepared from N N'-substituted Ilydrazides with at least one C NC H ₂ -CO group.

To obtain, for example, [2-p-nitrophenyl-i, 3,4-oxodiazolyl (5)] - acetonitrile, 15.3 g of CN-CH ₂ -

CON H-NH-C O-C

mixed phosphorus oxychloride. This mixture is heated for 2 hours in the oil bath at 130 to 140 ⁰ C. A thick oil is obtained which is poured onto 250 g of finely divided ice. A brown precipitate is formed, which is purified by boiling in alcohol.

It is noteworthy that with these new dye formers the color development works very well obtain different shades of color, depending on the type and substitution of component Y. The absorption maximum can also be shifted when the oxygen atom in the ring is replaced by sulfur or selenium.

For the practice of the invention, the new dye formers can either be photographic Emulsion can be incorporated immediately, be it before or after it is poured Emulsion on a suitable carrier, so that the color image during development by means of a

in which Z is O, S or Se and Y is hydrogen, is a substituted or unsubstituted aliphatic iso- or heterocyclic group.

ίο The reactive methylene group is also allowed through those atoms or groups which split off easily during development, such as e.g. B. !!Rome.

According to the invention, for. B. the following connections use for the production of color photographic images:

[2-p-Nitrophenyl-1,3,4-oxodiazolyl (5)] acetonitrile

N N (1)

[2-p-Tolyl-1,3,4-thiodiazolyl (5)] acetonitrile.

N- N (3)

) -NO ₂ with 15 cm ^{3 of a} phosaromatic developer, or they can also be added to the developer so that the color image is produced by developing the latent photographic image using an aromatic developer which contains one of the above-mentioned dye formers. In the first case, the component R preferably contains a group which makes it diffusion-proof.

According to the invention, a developing bath of the following composition is used for obtaining color images used:

A) N, N-diethyl-p-phenylenediamine chlorohydrate ..5g

Sodium sulfate (crystalline) 10 g

Sodium carbonate (crystalline) 100 g

Sodium hydroxide ig

Water 1000 cm ³ , _g

B) [2-p-nitrophenyl-i, 3, 4-oxodiazolyl (5)] -

acetonitrile ig

Acetone 30 cm ³ .

For use, B) is added to A).

According to the invention can be photographic color images both on plates and papers as also produce on films, using gelatine or other substances as a binder for the silver salt can be. Likewise, according to the invention, materials can be processed without distinction, go which contain one or more layers on one or both sides of the support.

The silver image produced by the development can be removed by treatment in a bleach bath easily remove. The bleach bath used may of course reproduce the color image that was created at the same time do not affect harmful. For example, one has an aqueous solution of potassium ferricyanide and sodium thiosulfate bleach bath have the great advantage of silver to remove without damaging the color image obtained according to the invention.

Claims (1)

P A T E N T A N S P P, Γ C. II E: ι. Process for the production of photographic color images by color development, characterized in that that a compound of the following general formula is used as a dye former: 110 N ■ N Y-C C-CH ₂ -CN, in Z equals O, S or Se and Y equals Hydrogen or a substituted or unsubstituted aliphatic iso- or heterocyclic Group means. 2. The method according to claim 1, characterized in that that a photographic developer is used which contains the dye former, 3. The method according to claim 1, characterized in that that a photographic emulsion is used which contains the Farlysiluff former. 609 6.