US2080041A

US2080041A - Method of producing color-photographic images and cinematograph films and light-sensitive emulsion therefor

Info

Publication number: US2080041A
Application number: US12254A
Authority: US
Inventors: Gaspar Bela
Original assignee: Individual
Current assignee: Individual
Priority date: 1934-03-29
Filing date: 1935-03-21
Publication date: 1937-05-11
Anticipated expiration: 1954-05-11
Also published as: GB458256A; BE408654A

Description

May ll, 1937. B, GASPAR 2,080,041v METHOD OF PRODUCING COLOR PHOTOGRAPHIC IMAGES AND CINEMATOGRAPH FILMS AND LIGHT SENSITIVE EMULSION THEREFOR Filed March 21, 1955 N 1 5e/a @a5/Joy',

GUM wea;

Patented May 1 1, i937 STATES METHOD oF PRoDUCiNG coLoa-rnoro- GRAPHIC IMAGES AND oiNEMA'roGRArn FILMS AND f SION THEREFOR LIGHT-SENSITIVE u EMUL- Bela Gaspar, Brussels, Belgiign Application March 21, 1935, Serial No. 12,254 In Germany March 29, 1934 vs claims.

This invention relates to a method of producing single-color or multi-color photographs and cinematograph lms.

It is known to `produce photographic images with the assistance of materials containing the dyestufl', which is necessary for the formation of the image, in the light-sensitive layer. The absorption of the colored layers is, however, obstructive for numerous purposes in the photographic art. In particular it is impossible to sensitize the layers sufficiently in respect to the spectral ranges in which the dyestuffs perform absorption.

The subject matter of the invention is a method by which there may be obtained a suihcient amount of dyestuf as required for photographic and more particularly color-photographic purposesin such a form that the presence of the dy'estui does not prevent the light from reaching the sensitized particles even in the absorption range of the dyestui.

It has been found that dyestufs in coarsely dispersed form (for example, in the form of'intermittently distributed particles of powder) color the b-inding4 agent merely weakly or practically not at all. The layers containing dyestui in coarsely dispersed form are highly transparent even for light which would be absorbed if the same dyestuifs were present in dissolved or finely distributed form. According to the invention, theV photographic image is produced in good transmittant layers of. this kind, and after exposure the emulsion layer is fastly dyed by dissolving the coarse grains of coarsely dispersed dyestu within the layer, whereupon the layer is rendered highly absorptive. The color intensity may be predetermined exactly by the amount of coarsely dispersed dyestui, dispersed in the emulsion during the manufacture of the material. The latent silver image may be developed before or after the transformation of the coarsely dispersed dyestuff into finely distributed dyestui. The dyestui is then locally destroyed proportional to the metallic silver image.

By way of explaining the invention, reference may be had to the single ligure of the accompanyingv drawing which represents a ow diagram showing the various steps in the practice of applicants method.

As will be understood from the following description, the sequence of the steps in my'improved method'may be changed provided that the unexposed material contains the coarse grained dyestui and that the dyestuff dissolution comes after the exposure.

The dyestuii is introduced into light-sensitive (ci. sis-s) layers, or into the solutions or emulsions employed for producing the same, in coarsely dispersed form exhibiting little or no absorption. Under these conditions there will occur merely a weak coloring and a small shading effect of the particles. The dye'stu', after the exposure, is then converted at a desired point in the treatment of the image from the coarsely dispersed, non-coloring form into the color-effective form. This is performed either by means of suitable solvents or by chemical substancesv which cause a. diffuse coloring of the layer. It is immaterial whether these agents transform the dyestuff chemically or convert it into a colloidal or highly dispersed powerfully absorbing form.

Example-Spirit Fast Red B (Ullmann, Enzyklopdie der Technischen Chemie, 2nd ed. vol. 9, page 572) in powder form is admixed with gelatine. The proportion of powdered dyestu to gelatine must be so chosen that after pouring on to a support the powdered dyestui is distributed intermittently; i. e., that the gelatine still-possesses a good transparency. The quantity of dyestuif should also not be greater than is necessary for a sui'liciently good diffuse coloring of the layer. obtained during the later process by converting the dyestui into the nely dispersed color-effective form, for example by bathing in a dilutedV alcohol solution.

The solution must have a concentration at which on the one hand the gelatine still swells, but at which on the other hand the dyestui is dissolved. With an excess of powdered dyestui the shading effect is too considerable, which is detrimental to the exposure of the layer. Y For producing layers whichcontain dyestufl's in coarsely dispersed form, dyestuis are very suitable which are insoluble or difcultly soluble in water assuming that water-'soluble or saturable binding agents (for example gelatine) are employed. For binding agents which are insoluble in water dyestuis will be employed which are insoluble or difllcultly soluble in the solvents for the binding agent. t

' The dyestuff is either introduced into the binding agent mechanically prior'to pouring, or applied to the surface of the layer either by dusting on or by pouring on to the layer in a suspension, with or without binding agents. The dyestuif may also be dissolved in a solvent, which does not cause swelling of the binding agent and upon evaporation leaves the dyestuf as a coarsely distributed sediment.

The dyestu may be introduced into the bind- 'Ihis diffuse coloring is then gelatine solution by rapid agitation. The dyeing agent' by means of an auxiliary solvent. For example, a water-insoluble, alcohol-soluble dyestui `is dissolved in alcohol, and introduced into stui will be precipitated in larger or smaller size of grain dependent on the nature of the agitation and the concentration of the dyestuif solution. r v

In this connection it is to be observed that in the gelatine solution the alcohol should not reach that concentration at which the grainsv of dyestuif again dissolve. Alcoholic solutions of Quinoline Yellow-spirit-soluble (Schultz Farbstofftabellen 'lth ed. vol. 1, No. 917) and the tannates or abietinates of basic dyestuiis, for example of Methylene Blue (Schultz, loc. cit. No. 1038) Janus Blue (IndoineBlue B, Schultz, locncit. No. 286), Red (Schultz, loc. cit. No.,557) or Yellow (Schultz, loc. cit. No. 292), or of Chrysoidine (Schultz, loc. cit. No. 27) are suitable. These solutions are poured into water, the dyestui salts then being precipitated in ake or granular form. .The watery suspension oftthese particles of dyestuil is mixed with gelatine solution. 'I'he solutions-may also be poured directly into the gelatine. The dyestuffs may also be dissolved invwater and precipitated. .After the precipitation the deposit' is ltered and freed from excess of precipitating agent by washing, and then mixed with a binding agent with or without a light-sensitive substance. The precipitation may also be perfumed in the presence of the binding agent. If there is a sujcient excess of the precipitating agent, a coarsely dispersed precipitation of the dyestui maybe obtained. In this case the conditions are the same as in the preparation of the emulsion, in which it is possible by varying the known factors to obtain coarse-grain or fine-grain deposits in the layer. In addition to the basic dyestuffs aforesaid acid and substantive dyestuis, such as Anthosine (Schultz, loc. cit. No. 51) li/etanill Yellow (Schultz, loc. cit.'No. 169), Naphthylamine Black (Schultz, loc. cit. No. 229) and Diamine Pure Blue `(Schultz, loc. cit. No. 510), are also suitable.

These are precipitated with salts of the alkaline earths,l magnesium or with heavy metal salts, such as zinc orA silver salts, oralso with salts of organic bases, for example aniline or naphthylamine. be precipitated by the addition of salt.

The precipitation may take place both in water as well as in the presence of binding agents. The size of grain will depend only on the known factors. The binding agent solution may be allowed to solidify, and freed from the soluble constituents in the usual fashion by washing.

The most suitable are very dimcultly soluble dyestuffs, which dissolve in 4water only when hot and upon cooling are completely precipitated. These may be employed Without precipitating agents. The dyestui may also be allowed to form immediately in the coarse-grain form in solution or in the binding agent fromthe. preliminary stages or components, for example from 'I'he di'iculty soluble dyestus may also treatment of the image the dyestufls are converted into a 'condition in which they develop their full coloring effect, i. e., diffusely color the layer. For diiuse coloring of the llayer the coarsely dispersed dyestu located on the surface of the layer or below the layer may creep into the layer and diifusely color the same.

There are various possibilities of converting the coarsely dispersed dyestuff; into the powerfully absorbing, dissolved or' nely distributed form.

.For example, a tannic salt of a basic dyestufi will pass into solution with acids. It is advantageous if the acid employed possesses chemically agreater alnity for the dyestui than that used for precipitation. Numerous salts of aciol dyestuis pass into solution with diluted alkalis or also with acids. For example, the dyestu passes from the barium salt of chrysophenine or anthosine into solution in 1% sulphuric acid. In this case barium sulphate is formed. The barium sulphate is more diiicultly soluble than the dyestuii` salt, i. e., barium has a greater 'i'i .l ity towards the sulphate-ion, and accordingly, the dyestui is again liberated. The coarsely dispersed grains pass into solution either in the presence of the acid or upon the subsequent washing, the layer being difusely colored. Neutral dyestus insoluble or diilicultly soluble in water pass partially into the diiusely coloring soluble form in a Weak acid or also alkaline solution. Very suitable, for example, are those water-insoluble or diicultly soluble dyestuis such as employed for dyeing acetate silk.

It is also possible to employ vat dyestuis in coarsely dispersed form, and to treat these with an alkaline hydrosulphite solution' in the layer.'

whereby the layer is difusely colored.

The diuse coloring of the layer may be easily regulated by the duration of the bath or by suitable interruption baths, such as water or like means, which act in chemical opposition to the dissolving agents, so that in case of requirement a bleeding of the dyestui or passage of the dyestui from one layer into the other may be prevented.

The most suitable for this purpose are' solutions of precipitating agents, which are capable of causing the process of diffusion to be .stopped when a sufficient diiuse coloring of the material has been attained. It has been found to be oi particular advantage to employ those precipitating agents,` which not only prevent the diusion but also improve the fastness or insolubility of the dyestuff, for example metal salts, such as' aluminum or copper salts, which form mordants or lakes, or for basic dyestuls solutions of phos- -photungstic or phosphomolybdic acid.

There is employed with advantage upon the conversion of the vcoarsely dispersed dyiestuil, which colors the layer only very little or not at all, into the coloring form one of the baths usual in photographic processes, the alkaline, acid or solventconcentration of which is adjusted according to the dyestui employed. For example, the conversion of a dispersed dyestu, which reacts in an alkaline agent, into the coloring form may take place in the developer. If an acid medium is necessary for this purpose, there will be employed either the interrupting bath following on the developer, the acid xing bath, or

a dyestuff-destroying bath, for example a solution of thiocarbamide containing mineral acid.

The dyestuif may be caused to color the layer diiusely by physical action.

Examples.-'1. In a llayer of resin a coarsely 2. On to the surface of a layer there is dusted a fusible dyestufi in powder form which, after the exposure, is caused to color the surface diffusely by fusing.

The production of the dyestuff images inthe layers in accordance with the invention may` l5 take place in desired fashion according to the methods usual in the photographic and colorphotographic art, preferably by local destruction of the dyestuff in accordance with earlier processes of the applicant. It is possible to produce 2@ with vthe dyestuff in the layer for example washout reliefs or mordant or tanned images, or also to remove the dyestuii' from the tanned points by solution.

The layers containing coarsely. dispersed dyestuff may be sensitized with desired substances,

for example with silver halide, with light-sensitive heavy metal salts, such as those of iron orl mercury, With chromates, or also with organic light-sensitive substances, such as diazo compounds. The light-sensitive substances may either already be added to the emulsion or introduced subsequently into the nished layer. Themost important use of the layers consists, however, in the combination with silver halide in one or more layers, which if desired may be differently sensitized.

The technical advantage of the invention resides in the extensive decrease or preclusion of the interferlngabsorption (screening eiect) of 4G the layers .which contain the coarsely dispersed dyestuis. This is particularly important in the production of color photographs and cinematograph films. l According to the present invention,

color photographic and cinematographic expoe sures and copies may be made in direct fashion from colored originals, wherebyv the layers may be well sensitized directly for the complementary color.

A preferred form of embodiment of the invention resides in the use of photographic materials having layers poured one on to the other, these layers containing diierent dyestus and possessing different spectral sensitivity. In this connection, in addition to the reduced absorption of the dyestuis, the great lack of diffusion on the part of the superimposed layers offers particular advantage. In the same manner it is also possible to produce different dyestuffs and diierently color-sensitized particles of emulsion, which are superimposed or juxtaposed in screen-like fashion. These are produced by mixing or reemulsifying the differently colored and sensitized particles of emulsion. 'I'he dyestui. however, may also be provided in coarsely dispersed form above or below the light-sensitive layer in screenlike fashion. Further, there may be produced according to the invention not only colored lightsensitive layers. but also multi-color screens or layers which are diffusely colored subsequently after the exposure. The dyestuifs may also be combined with sensitizers and auxiliary lter dyestuis. For this purpose there may be employed iilter dyestuis which are capable of being both readily washed out as well as destroyed in 75 the treatment baths.

It is also possible to combine colorless layers or layers or particles of layers which are diffusely colored or contain dyestuff-formingsubstances.

The coarsely dispersed dyestufis may also be applied above or below the light-sensitive layer with or without binding agents by dusting on or, as described above, with the assistance of solvents.

The dyestui employed may be selected either' to `be complementary or similar to the color sensitivity of the layer or also independently thereof. It is thereby easily possible to produce master images,`the color of which is complementary to the color sensitivity of the colored copying layers employed.

An additional advantage of the process according to the invention occurs in those cases in which the layer contains dark dyestuifs, e. g. in connection with documental-or reversal papers or films, which must give dark pictures. In such cases, it would be diiicult to obtain a suiicient exposure if the dyestui is present in the layer in nely dispersed form. If, however, comparatively large dyestuf particles are in the layer, there are suiiicient gaps for the light to penetrate. In a similar manner gelatine layers for the chromate process can be made with coarsely dispersed dyestuffs, which are transformed after exposure into a nely dispersed form.

On the layers according to the invention it is also possible to produce sound records, either in colors or also in black-and-White. It was surprising in this connection that the coarsely dispersed grains of dyestufi had no adverse effect on the sharpness of the sound copy. An advantage resides in the fact that the sound may be copied with the light ofA the normal soundcopying machines, which is comparatively Weak for colored layers.

What I claim as new and desire to secure by Letters Patent is:

1. The method of producing photographic dyestui' images which comprises exposing a light sensitive silver halide emulsion layer, the said layer containing coarse grains of fast dyestuff coarsely dispersed in an Vemulsion which will transmit light raysfor which the coarsely distributed dyestuf possesses absorption properties, fastly dyeing the emulsion layer at a point in the process after exposure by dissolving the ,1 coarsely dispersed coarse grains of dyestui withdeveloping vthe latent silver image and destroy-` ing the dyestui locally proportionate to themetallic silver image.

3. The'method of producing photographic dyestui images which comprises exposing a plu-l rality of superimposed light sensitive silver halide emulsion layers, at least one of the said layers containing a fast dyestui in the form of coarse grains coarsely dispersed in an emul- 4 Y aosaoai .at a point in the process after exposure by dis- 5 solving the coarsely dispersed dyestui within the layer, developing the latent silver image and destroying the dyestui locally proportionate to the metallic silver image.

4. The method of producing photographic dye- 10 stuff images which comprises exposing a plurality of light sensitive silver halide emulsion.

layers, at least one of the said layers containing a fast dyestut in the form of coarse grains coarsely dispersed in an emulsion which will transmit and y 25 dispersed coarse grains o'f fast dyestuis in the light sensitive emulsion prior to exposure and dissolving the grains within the layer after exposure.

6. A light sensitive photographic material `comprising a silver halide emulsion layer and 5 coarsely dispersed coarse grains of fast dyestui within the said emulsion, the layer being adapted to 'transmit light of the spectral range in which the dyestuff performs maximal absorption. v

7. A light sensitive photographic material comprising a silver halide emulsion layer and coarsely dispersed coarse grains of fast dyestufl.' within the said emulsion,- the layer being adapted to transmit and predominantly sensitive to light l5 of the spectral range in which the dyestu perf forms maximal absorption.

8. A light sensitive photographic material comprising -a plurality of silver halide emulsion layers and coarsely dispersed coarse grains of 20 fast dyestuff within at least one of the said emulsion layers, the said oney layer being adapted to transmit light of the spectral range in which the dyestui performs maximal absorption.

BEL GASPAR. 25