DE1004047B - Color photographic process for the production of monochrome or multicolor images - Google Patents

Description

GERMAN

The invention relates to a method for producing single-color or multi-color images by means of light-sensitive iron salt layers. It is known that ferric salts turn into ferrous salts when exposed to light reduced what is used photographically. This reduction is also included has been used with other substances, for example with remote compounds or with silver salts to create colored or black images behind master copies. In the reaction between In ferrous salts and silver salts, metallic silver is formed in finely divided form as an image substance.

It is also known that silver images obtained from photographic silver halide emulsions by Exposure and development have arisen, can be converted into colored compounds. It is too it is known that such silver images are produced by fading and redevelopment in a chromogenic developer can be replaced by dye pictures. Those obtained from photographic layers Silver images are all made up of more or less coarse silver grains, including those caused by fading of the silver images and chromogenic redevelopment have formed dye images, if not exactly a graininess, but a certain one, Inhomogeneity of color density corresponding to the grains. Many attempts have been made this inhomogeneity, which occurs with strong enlargement, z. B. is annoying when projecting movies, too eliminate or reduce, but without achieving a completely satisfactory result to date would have been.

It has not yet been possible to replace the grained silver halide layers with others To replace layers that contain the light-sensitive substances in a sufficiently fine distribution. the Photosensitive layers working with ferric salts contain the photosensitive substance in a much finer distribution than the silver halide layers, their utilization for the However, the production of multicolored photographic images has not yet been achieved in a satisfactory manner. The processes that work according to the previously known processes with iron salts and silver salts only have led to blurred and heavily veiled images.

These disadvantages are eliminated by the invention. The inventive method consists in that silver images, which are known per se Process for the reduction of silver salts by means of the ferrous salts formed by exposure to ferric salts have been obtained, chemically converted into a color image in a manner known per se will. This conversion into dye-color ph.otographiscb.es procedure

for making monochrome or

multicolored images

Applicant:

Michele Pasquale Luigi Martinez,
New York, NY (V. St. A.)

Representative: Dr.-Ing. K. Boehmert

and Dipl.-Ing. A. Boehmert, patent attorneys,

Bremen, Feldstr. 24

Claimed priority:
V. St. v. America August 21, 1953

Michele Pasquale Luigi Martinez, New York, N.Y.

(V. St. A.),
has been named as the inventor

According to the invention, images are produced by bleaching the silver images obtained by the ferric salt process and by means of a chromogenic developer, which in the presence of a color coupler is known per se Way provides a dye through oxidation, can be redeveloped.

The method according to the invention can also be used to generate a multicolored image. The procedure is then that the film is impregnated after the first chromogenic development or applying ferric salt solution repeatedly made photosensitive and exposed is, whereupon by treating with silver salt solutions each time another silver image is created and like that first bleached out and developed into a different partial color image through chromogenic development will. By repeating these operations several times, an image can finally be obtained which reproduces the colors of a given subject.

The advanced effects of the invention are particularly evident when that Silver salt in an easily reducible form, for example after precipitating and redissolving in excess Ammonia is used, preferably along with a small amount of an alkaline Salt that does not fall iron salts, such as borax, and further along with a small amount a retardant such as an alkali sulfite.

60S 838/346

Another advance of the method according to the invention is its greater speed, the is achieved by repeatedly impregnating the film with that containing a ferric salt Sensitization solution is made while the film is from the previous treatment course is still wet.

It was further found that the reduction in the temperature caused by the presence of a color image in the layer The effect of a subsequent exposure can be compensated for by the film at repeated impregnation with a sensitizing solution containing a ferric salt each time with treated with an increased ferric salt concentration.

The sensitivity and thus the speed of the method according to the invention can thereby be increased be that in one or more of the successive resensitizations of the used A small amount of gelatin is added to ferric salt solution.

The method according to the invention can be adapted to the different characters of the master copies by adding a small amount of a to the ferric salt solution used to sensitize the film the image contrast-increasing agent, for example a salt of chromic acid, is added.

The use of the invention to produce multicolored motion picture films shows the progressiveness of the new method in terms of speed in that according to the invention with a ferric salt sensitized motion picture film in a continuous The process is further processed after the sensitization, whereby the film, without stopping, for exposure and runs through the following treatment stages.

The ferric salts are preferably used in aqueous solutions, on the one hand with suitable Agents can be added, for example with gelatin and other colloids, gum arabic, viscose and other suitable means, or on the other hand simply on a previously with a colloid layer coated carrier or on a carrier made of a porous, water-absorbent or water-adsorbing material such as paper, fabric, regenerated cellulose, spongy Rubber, suitable plastic compounds, natural or synthetic resins, cellulose esters, etc. or is covered with these substances.

The following is an example of a simple iron-silver photosensitive solution containing gelatin for application on non-pretreated surfaces or on previously with an adhesion of Gelatin layers promoting substrate treated areas listed:

Distilled water 100.0 ecm

Gelatin 8.0 g

Ferric ammonium citrate 10.0 g

Silver nitrate 3.4 g

A much better, albeit more complicated, composition is:

Distilled water 100.0 ecm

Gelatin 8.0 g

Ferric ammonium citrate 12.0 g

Ammonium nitrate 3.0 g

Silver nitrate 3.4 g

Lactic acid 5.0 g

Ferric ammonium sulfate 1.0 g

Potassium dichromate 0.05 g

Methyl alcohol 5.0 g

The same composition can be used for water-absorbent or adsorbent material or on surfaces previously coated with gelatin Find. In this case, however, the water should be reduced to 75 ecm in the composition and the Gelatine, which is used here for thickening and also increases the sensitivity to light, is either omitted entirely or reduced to 1 to 2 g.

Upon exposure, the photosensitive layers thus obtained turn dark brown and black copied out. You only need to rinse in water for 1 minute, then fix in 15% fixing sodium solution for 1 minute and then a wash for 5 minutes. The silver image thus obtained is then treated in any manner known to obtain color images, for example by fading and color development, oxidation and re ^ production process, toning, dyeing, ozobromine process, dye soak process, etc. One described in detail An example of such a color conversion method will be given later.

The following are examples of ferric salt solutions that after exposure to a Silver solution to be treated.

The simplest composition is for use on suction layers or on layers that previously treated with a substrate causing permanent adhesion of a gelatin layer are the following:

Water 100.0 ecm

Gelatin 7.0 g

Iron ammonium oxalate 10.0 g

Another composition is the following:

Water 100.0 ecm

Gelatin 10.0 g

Iron ammonium oxalate 15.0 g

Ammonium oxalate 2.5 g

Ammonium chromate 0.05 g

An example of a composition for impregnation, e.g. B. by immersion or spraying a water-absorbent material or a surface covered with gelatin is similar to those given above Compositions with the difference that the specified amounts of water in each case reduced to 75 ecm and the gelatin either omitted entirely or reduced to 1 to 2 g will. Such an improved composition would e.g. B. be:

Water 100.0 ecm

Ferric chloride 3.0 g

Oxalic acid 1.5 g

Ferric ammonium oxalate 10.0 g

Sodium oxalate 2.0 g

Ferric ammonium sulfate 1.0 g

The ferric sulfate and oxalic acid promote the contrast effect. A small amount of gelatin, 1 to 2% of the water content speeds up the process considerably. These non-silver containing solutions act faster on exposure than solutions containing silver. But they cause when exposed no visible image, just a very dull reproduction of the most exposed parts.

After exposure, the material is in each case directly for 30 seconds up to 1 minute in a 1 to 2% solution of silver nitrate immersed in distilled water. One suitable for this purpose improved silver nitrate solution is:

5 6

Distilled water 100.0 ecm are layered. This advantage along with

Silver nitrate 2.0 g accounts for the absence of noticeable grain

Ammonia as required, the superiority of the new process,

(with "on demand" is defined as the amount of S ^{v esehen n} ° ^{of the,} fact that the new method

is necessary to make the brown ⁵ that forms first is much more economical

To dissolve precipitate again). ^{These points} > namely the increase in the

~. .j, · f ... high quality, balancing and standardization

Then add: _{are nkht {n the following general} examples

JNatnumsuint u.lö g included, as they only depend on the particular

^orax '^ ίο Properties of the various negatives of a color

Immediately after using the silver nitrate solution, apply as the following shows a distinctive image in Sepiabis black: the examples only serve to provide a complete and Rinse, 1 minute; Fixing, 1 minute, in 15- clear description of the average working bis 20% fixing soda solution; on washing to give gears.

about 4 minutes. i ₅ The following are examples that

The silver image obtained in this way is then, as in the whole process step by step in the manufacture

in the cases described above, treated in order to position multicolored cinematographic fiI-

to detail a colored menu by any known technique.

To achieve image. . .

On the general properties of light em- ployment example!

Coming back to sensitive ferric ion layers, let it be step 1. One coated with simple gelatin

thinks that with careful, repeated prak film (e.g. by fixing and thorough

three novel points of considerable washing of a commercial, positive film

licher meaning: can be held) will be 1 minute in one off

1. The gelatin layers seem to have an unlimited 25 100 ecm distilled water and 15 g ferriammo ability to have ferric ions immersed over and over nium oxalate existing solution. nothing to reabsorb and adsorb. For example, further is required. The film then turns into one a piece of a fixed movie was dried up to eight streams of warm air, which was only one more Painting sensitized and re-sensitized, taking minute.

Each time a good, strong image is shown, i.e. 30 Step 2. The film is placed under the green filter Images on the same piece of film. negative of a color set by a strong and on

2. The rapidity of the light exposure grows exposed to ultraviolet rays rich light source, with a photosensitive gelatin iron salt layer which will take about 1 to 3 seconds depending on the strength of the light source and the density with increasing saturation with absorbed or ad- the negative,
sorbed ferric ions; Therefore, if a gel has already taken a colored image into the ammotine layer for 30 seconds, niacin and sulfite as well as borax containing silver nitrate will only use a reduced amount or area of impregnation solution of the specified formula; Rinse, 1 minute; gnable colloid be present. This would involve fixing, 1 minute, in 15 to 20% fixation matron. Continuous reduction in the speed of the solution; Wash, 4 minutes.

Light exposure with each impregnation effect, 40 Step 4. Bleaching, 1 minute, in a solution of what but to a certain extent by an increased 100 ecm of water, 7 g of potassium ferricyanide and 7 g of new concentration of the ferric salts in the resensitivity potassium oxalate , Washing, 2 to 4 minutes,
The solution used is compensated for. In step 5, immersion in a color developer with a composition of ferricammonium oxalate has been shown in the following practice: 100 ecm that if a 2% aqueous sodium carbonate solution is used for a first impregnation, the 10 to 13% aqueous solution Solution of the salt for the preparation also contains 0.5% sodium sulphite, to which 2 ecm of a place of a first color image is used, with a 5% solution of diethyl-p-phenylenediamine-hydro, a second subsequent impregnation a 22% chloride in methyl alcohol and 2 ecm of a 2% solution of the same salt can be used. Solution of p-nitrobenzyl cyanide in equal parts and with a third impregnation the saturation of acetone and methyl alcohol are added. Can be in 30%, with preferably up to 2% 2 to 5 minutes forming, the desired purple gelatin is added. This way you can picture. Washing, 2 minutes; Bleach, 2 minutes, in depending on the requirements the exposures from the same bleach as in step 4; Wash; Fixed, standardized or corrected, where, for 2 minutes, in 15% fixing soda solution; it must also be taken into account that the 55 washing, 4 minutes.

separate elements of a set of separations Step 6. Wiping off surface moisture

negatives can be of different densities (drying is unnecessary). Then re-immerse

and therefore compensation is required. (of the same material) in a sensitizer

3. With each impregnation, the iron salts penetrate step 1 and appropriate drying.

in each part of the layer in which the impregnable 60 step 7. The same colloid resensitized in this way is still free or partially free; z. B. also material is exposed again, with the red filter partially under a previously formed image. Wherever the purple image is placed in negative register, where the ferric salts penetrate in this way, step 8.Step 3 is repeated exactly,
get a picture afterwards. The resulting multi-step 9. Step 4 is repeated exactly,
Color images are therefore not layered on top of each other. Step 5 is produced with the single alteration, but actually repeated by a change that instead of the mentioned mixture of images is composed, which all p-nitrobenzyl cyanide solution the same amount (2 ecm) when projecting lie in the same plane. This is a 5% solution of phenyl phenol sodium salt in a significant advantage over any other methyl alcohol used. All processes are known color formation processes, most of them more than 7 ° as with the corresponding process. It forms

a blue-green image on top of the previously formed purple image.

Step 11. Repeat step 6.

Step 12. Repeat step 7 using the blue filter part negative of the sentence.

Step 13. Repeat step 8 (= 3).

Step 14. Repeat step 9 (= 4).

Step 15. Repeat step 10 (= 5) with the further modification that instead of the p-nitro compound and the phenyl-phenol salt the same amount (2 ecm) of a 5% solution of aceto-acetanilide in Methyl alcohol is used. All operations as in the corresponding step. The final multicolor image is thereby obtained.

Example II

An unexposed positive film becomes one under a green filter negative in the normal manner Color set copied and developed, fixed and washed in the usual black and white process, ao The silver image is bleached in a suitable bleach, then washed, followed by all the steps of example I from step 5 onwards.

Example III

An unexposed positive film will normally be placed under a green filter negative of a color set copied and then directly chromogenically developed in a known way to a purple image, also in a known way Wise freed from silver and washed on it. "This is followed by all steps from step 6 of Example I.

Deviations in the order in which the pictures are produced in the different colors, can be made as desired. Double material, d. H. Material that with easier Gelatin or coated with silver halide emulsions on both sides can be used thereby shortening the entire process since then the sensitizing and other general baths can act on both sides at the same time, while covering one side is then necessary when a different reagent (e.g. different color coupler) is to act on each side.

It goes without saying that there are considerable variations in the amounts and types of in all compositions Ferric salts possible.

From the above description it is apparent to the person skilled in the art that the object of the invention in can be achieved in a number of different ways, and the invention is therefore not intended to be limited by that given examples, but only in accordance with the attached claims.

Claims (12)

Claims: 55 1. Color photographic process for producing monochrome or multicolor images, thereby characterized in that silver images produced by the known method of reduction of silver salts by means of the ferrous salts formed by exposing ferric salts to light are chemically converted into a color image in a manner known per se. 2. The method according to claim 1, characterized in that the film after the conversion of the Silver image in a dye image to be painted repeatedly by impregnation with ferric salt solution re-photosensitized, exposed and treated with a solution containing silver salt and these silver images are replaced with dye images. 3. The method according to claim 2, characterized in that the repeated times again photosensitized film with each exposure under a different color separation of a color set exposed and the silver images obtained in this way are converted into a different dye image each time will. 4. The method according to claims 1 to 3, characterized in that the individual silver images can be converted into color images by bleaching them and using a chromogenic Developer which, in the presence of a color coupler, supplies a dye by oxidation to be developed. 5. The method according to claim 1, characterized in that a film is used in its photosensitive layer contains a silver salt. 6. The method according to claims 1 to 4, characterized in that the silver salt in easily reducible form, especially used after precipitating and redissolving in excess ammonia is, preferably together with a small amount of an alkaline salt, the iron salt does not fall like borax and further along with a small amount of a retardant such as an alkali sulfite. 7. The method according to claims 1 to 6, characterized in that the repeated impregnation of the film made with the photosensitive solution containing a ferric salt becomes while the film from the previous treatment is still wet. 8. The method according to claims 1 to 7, characterized in that the repeated impregnation of the film is made with a solution containing a ferric salt, which in each of the successive applications has a higher ferric salt concentration. 9. The method according to claims 1 to 8, characterized in that in one or more the successive resensitizations of the film of the ferric salt solution used for this purpose small amount of gelatin is added. 10. The method according to claims 1 to 9, characterized in that the light-sensitive of the film used a small amount of a ferric salt solution to increase the image contrast Means is added, such as a salt of chromic acid. 11. The method according to claims 1 to 10, characterized in that the color image on a motion picture. 12. The method according to claim 11, characterized in that that the motion picture film made photosensitive with a ferric salt in a continuous Process is further processed in which the film is made from photosensitive for exposure and runs through the following treatment stages. Documents considered: French Patent No. 1 035 112; Eder, "Handbuch d.Photographic", Vol. IV, Part 4, 1929, pp. 89, 100, 106, 109. © 609 838 / 3Φ6 2.57