US2036945A - Process for the production of colored pictures, particularly in natural colors on paper, films, and the like - Google Patents

Description

7, 193%. ERG 29@36945 CULARLY F. L] PROCESS FOR THE PRODUCTION OF COLORED PICTURES PAR'II IN NATURAL COLORS ON PAPER, FILMS AND THE LIKE Filed March 15, 1934 Patented Apr. 7, 1936 PATENT OFFICE PROCESS FOR THE PRODUCTION OF COL- ORED PICTURES, PARTICULARLY IN NAT- UEAL COLORS THE LIKE N PAPER, FILMS, AND

Friedrich Lierg, Vienna, Austria Application March 15, 1934, Serial No. 715,718 In Austria October 15, 1932 1 Claim. (c1. 101-149 This invention relates to a process for-the production of colored pictures particularly in natural colors'on paper, films and the like whereby colloid printing images produced by tanning in a picture-like manner or colloid relief images are soaked with a metallic salt solution yielding together with the electrolyte the color precipitate. The present invention has for its object the improvement of. this process by carrying it out in an expeditious manner. It is already known to embody the reagent, yielding together with the electrolyte the color precipitate, into the printing surface in a water insoluble condition or in a state which can be removedby water with great difliculty only. In view thereof, the

1 application of precipitating solutions after the printing is dispensed with, an image of perfect sharpness and shading being formed during the printing, because the electrolyte hasno oppor- 2 tunity to spread over the printing layer. Consequently it is not necessary to washaway a precipitating liquid and remove the adhering liquid.-

The paper or the film can be preliminarily moistoned for the whole print and provided with the 25 color image is removed from the printing device. Care has to be taken that an excess of a solution of the electrolyte yielding color precipitates'does not adhere to "the printing matrices if they contactwith the printing layer, seeing tion. Therefore before the printing it is necessary 35 to remove the adhering solution from the matrix. Thepresent invention makes use of the.

characteristic that electrolytic solutions readily pass from colloidal layers and essentially consists in that before the printing the printing matrix 40 is placed into contact with a moist colloidal substance in which the electrolyte yielding color precipitates is embodied.

The invention can be carried out in different ways, an arrangement for carrying out the pres- 45 ent process for three color printing being shown diagrammatically and by wayof example in the accompanying drawing.

The colloid from which the electrolyte yielding color precipitates passes to the printing ma- 50 trix may be applied; for instance, in a thin layer to a preferably flexible base, for instance to a celluloid band, and alternately is led through the electrolyte solution and pressed onto the print ing film. Before this compression it is of advantage to remove the adhering excess of the that the electrolyte is applied'to the printing mat solution although it may be possible to press out any excess of the solution by this compression. Still the borders of the printing matrices may contain some excess of the solution. The excess is removed from the colloid layer preferably by 5 rubber wipers, rollers or the like. There is no danger that the colloid layer is damaged thereby, because, contrary to the printing matrix, the colloid layer forms an uninterrupted surface.

Anyresidue of the liquid can -be removed by m wiping rollers made of linen or the like or provided with a. finely, porous but non-colloidal surface. It has been found that the degree of concentration of colloidal layers, imbibed with electrolytic solutions of a certain degree of concentration, is not varied by contact with absorbent layers of non-colloidal characteristic. In this respect for instance filter paper possesses a certain colloidal characteristic which is noticeable in that the degree of concentration of the electrolytic w imbibition is varied in the colloidal layers. Washed out fabrics do not show this effect. Therefore it forms a part of this invention to remove an excess of adhering solution from colloidal layers, which are utilized for transferring the electrolyte yielding color precipitates to the printing matrix, by means of finely porous faces of a noncolloidal characteristic (terra-cotta, textile fabrics, metal fabrics, rubber sponge or the like). of course also the printing matrix can be treated with materials of this kind, for instance by textile fabric rollers which do not go the 1 fine characteristics.

In order to dispense with any means for removing the adhering liquid such as wipers, roll- 5 ers and the like it is proposed by the inventor to use a gelatinous colloidal mass containing the corresponding electrolyte and, besides the hardening agent (for instance chrome alum), also a moistening agent (forinstance glycerine).

When in contact with the printing matrix, the electrolyte yielding color precipitates passes from.

a colloidal mass of i this kind into said matrix until a state of equilibrium is reached. The electrolyte, withdrawn from the surface of the colloid, is uninterruptedly replaced from the interior of the mass. In case of a sufl'icient thickness of the colloidal layer, the concentration of the electrolyte is noticeably reduced only after a very considerable number of prints.

Further the withdrawn electrolyte can. be replaced from the backside. For this object it is not necessary that the colloidal surface is of any considerable thickness. The colloidal surface is applied for instance to a surface or a cylinder of porous clay or the like. The backside of the surface is in contact with the electrolytic solution or the cylinder is filled with the latter. This solution diiiuses through the porous wall and always maintains the colloidal layer on the same degree of concentration of the electrolyte. The electrolytic solution can be subjected to pressure in order to effect a fast diffusion through the porous wall.

In the illustrated arrangement for a method of expeditiously printing in three colors by means of electrolytic solutions, are employed endless film bands which carry the printing matrices in the shape of gelatinous wash-out reliefs. In the illustrated example, the printing, paper or the printing film is coated by a colloidal layer, containing a ferric salt, lead bromide and dimethylglyoxime as precipitating agent.

Rollers for leading and guiding the printing paper and the matrix film are arranged in a frame I. The printing paper I is wound oil. of a roller 3 and passes by way of rollers 4 through a water bath 5, and is led between rubber wipers 6 and pairs of wiping rollers l to a pair of rollers 8 and 9 for starting the proper printing process. The first printing arrangement for carrying out the blue print consists of an endless band l which is in the form either of a thin flexible metal tape carrying the individual printing matrices or of a celluloid band which, if desired, is provided directly with the washed relief. The

band ill moves over rollers ll, l2, l3 and I4 and around the drum 15. An endless celluloid band l8. which is coated with a colloid layer on its outside and passes over a roller l1, moves between the drum l and the band Ill, whereby the printing matrices face the drum IS. The roller ll partly dips into a trough l8, containing a solution of potassium ferrocyanide. The excess of solution is removed by rubber wipers l8 or porous rollers 20. During the movement over the drum ii, the solution passes from the band "5 to the printing matrices of the band I, which thus are permanently provided with the electrolyte yielding color precipitates up to a certain degree of concentration. The printing paper 2 is pressed onto the matrix band l0 between the rollers II and 2| and now both the printing paper 2 and the band l0 remain in contact until the rollers I! and 22 are reached. During contact the solution of potassium ferrocyanide embodied in the relief of the printing matrix I0 passes into the printing paper 2 and forms the blue partimage in the form of Prussian blue. Theblue part-image is the most important for the characteristic of the image and therefore here the absorption of the electrolyte from the solution is the most satisfactory, because by varying the concentration of the solution it is possible to readily change the force of the blue print. The yellow print matrices, arranged on the band l0 are imbibed with potassium monochromate for carrying out the yellow print now carried out.

For this object, a band l0 passes round rollers II l2 l3 I4 and a drum [5' the latter being coated with a thick layer 23' of a gelatinous substance containing the potassium monochromate. Thelatter is a very easily soluble salt and therefore a quantity suificient for-a long period of' printing is applied; very small quantities thereof passing to the printing matrices at a time. The printing paper 2, coming from the rollers l2 and 22, is pressed onto the band l0 between the.

rollers l I and 21' and is separated from the said .band on leaving the rollers l2 and 22. Now

the printing paper 2 passes between the rollers II" l2" and is pressed onto the band Ill carrying the red print matrices, which are imbibed with a nickel salt. In this case the drum I5" is' in the form of a hollow cylinder'of porous clay or the like, which is permanently filled with a solution of nickel salt. The outside of the clay a red image of nickel dimethylglyoxime in the layer of the paper. Finally the paper band I is wound up on a roller 20. The printing devices are driven by a common shaft 24 by means of worm wheel gears. Each worm 25 is separately adjustable on the shaft 24 in order to adjust the bands l0, l0 III" for coinciding exactly with the images on the printing band 2. For printing film bands for cinematographic reprorices, together with the dimethylglyoxime forms duction, printing matrices films of a length corresponding to the length of the film band to be produced are substituted for the endless bands I0 l0 it". Of course one ofthe printing devices can be used for printing pictures in a single color.

What I claim is:--

In a process for the production of colored pictures particularly in natural colors on the col? loidal printing surface of papers, films and the like containing reagents which with electrolytes yield colored precipitates in a water insoluble condition and in which colloid printing matrices produced by tanning in a picture-like'manner are imbibed with an electrolyte solution able to yield a color precipitate with said reagents, placing into contact said matrices with said colloidal printing surface to produce the precipitate in a picture-like manner, and separating said matrices from said printing surface, the step of providing said printing matrices with a colloidal surface soaked with said electrolytic solution before placing incontact said matrices with said printing surface.

FRIEDRICH IJERG.

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