US2177632A - Production of colored pictures - Google Patents

Description

' pasts 31, 1939 4 ,;f um:n I STATES Puss-r osslcs rnonuo'rrou or oommrrc'rms Ernst Bauer,

. Denna meme assignments, to Asia Binghamton, N. Y a m ntion at Delaware Ansco imatic N D Application August 5, 1936. Serial ram In i 2 Claims.

My present invention relates to the production oi colored pictures.

One of its objects isto provide a process for the production of improved colored pictures. Further objects will be seen from the detailed specification following hereafter.

' Colored pictures have been made by developing in colors a silver'halide emulsion by means of a developer, the oxidation product of which couples with a dyestufi component. It has also been proposed to convert the developed silver picture in a layer into a colored picture by the reaction of an azo-dyestufl component on silver anti-diazotate. By the first-mentioned process oneobtains, in-

" deed, blue and red tinted pictures free from obiection; the yellow picture, however, is, gener-' ally, somewhat too weak. By the anti-diazotate method there is obtained a beautiful red and yellow tint but the blue tint is less good.

The present invention is based on the observation that the'constituent .coior pictures can be harmonized to a great extent, if there is formed on a photographic material, having several layers superimposed on each other on one or both sides of a support, one or more partial color pictures by color development with diethyi-para-phenylene-diamine or the like, and other partial color pictures by the silver diazotate process through coupling with an azo dyestufi' component. In particular, it is advantageous to produce the blue and red constituents by color development and the yellow by the silver anti-diazotate method,

For the color development there come into question particularly color-forming components which have substantive properties in respect of the binding agent, like those whichare applied in the process of the co-pending application Ser. No. 72,718 filed by Wilmanns, Schneider and the inventor of the present application.

The azo-dyestufi pictures may be obtained, in

- particular, by the process of U. S. Patent 1,963,197

with use of dyestufi components which yield equal color tints by both methods.

The following example illustrates the invention:

The film to be used in this invention may be built up as follows:

The first, not specially sensitized layer, contains the substantive compound p-saiicyiic acid benzidide. The second orthochromatic layer contains, for example, i-(diphenyl) -3-methyl-5-pyrazolone. component i.2-hydroxy-naphthoic acid benzidide. By color development with the aid of p-dimethyls amino-aniline there is produced in the second The third layer contains as dyestufi August 1'], 1935 layer a red-picture and in the third layer a blue picture. I I i If the latent image is developed with p-dimethylamino-aniline there is produced, besides 1' moi. dyestufi' 4 mols. silver. After removing the undeveloped silver bromide the silver picture is converted in the known manner into a silver salt and this is converted into silver anti-diazotate by means of a soluble anti-diazotate, for instance diphenyl-dianti-diazotate. In the bath containing a weak acid solution the liberated diazonium compound couples with the p-salicylic acid benzidide. The silver salt remnant in the several layers is removed by fixing so that pure dyestufi. s

pictures are present in the finished him.

The film may also be developed with aid of an ordinary black and white developer. and fixed. This operation produces a better threshold value than the developer p-dimethyiamino-aniiine and better freedom from fog. The silver picture is then convertedinto a silver salt and this salt further developed with p-dimethylamino-aniiine. There is thus produced a silver picture and a dyestun picture. The silver is again converted into a salt and, as described above, caused to react .with anti-diazotate.. If desired the order of the treatments may be rever Further, the silver produced in the black-andwhite development may be dissolved and after a second exposure the residual silver bromide may be developed with p-dimethyl-amino-aniline and the metallic silver thus produced converted in known manner by means of silver anti-diazotate into an azo-dyestufl picture.

One can, therefore, by this invention obtain as desired positive or negative color pictures which by combination of the individual development processes may be profoundly influenced in their tints. A further possibility of the correction of color tint resides in the fact that one or other of the processes need not be allowed to proceed through the complete depth of the three layers but may be only partial in its action.

What I claim is:

1. A process of producing colored pictures with the use of a photographic material having three superimposed emulsion layers and containing in the first emulsion layer p-saiicylic acid benzidide, in the second'layer 1-diphenyl-methyl-5-pyrazolone, and in the third layerl-2-hydroxynaphthoic acid benzidide, which comprises color-deveioping said photographic material, removing the undeveloped silver salt, converting the silver picture still present after color-development into silver anti-diazotate, liberating the diasonium compound to couple with said p-salicylic acid benzidide, and fixing said photographic material. 2. A process of producing a colored photo graphic picture, which comprises exposing to,

light controlled by an object to be reproduced a three-layer photographic element, two layers of said element comprising 9. color iormingmlevelopment component fast to difl'usion for the blue and the red picture respectively, and one layer comm prising a substantive azo dye component; develo mimu element with an aromatic smiho dev'eloper thereby tannins a all!" and color picture in cid two first-mi ed laye s in a sinsle development step, sud asilver pictu e n mid lec-