US1828974A - Photographic film with visible reproducible inscriptions - Google Patents

Description

Oct. 27, 1931. H. LUMMERZHEIM ET AL 1,828,974

PHOTOGRAPHIC FILM WITH VISIBLE REPRODUCIBLE INSCRIPTIONS Filed on. 29, 1927 nooomoooooosooooooo O O O O U U O O O OO q O O U O O O ma a.

Patented Oct. 27, 1931 UNITED STATES.

PATENT OFFICE HERMANN LUMMERZHEIM, F DESSAUPZIEBIGK, ANDEDUARD SOml'ITZLER, OF DF SAU. IN ANHAL'I, GERMANY, ASSIGNORS, BY MESNE ASSIGNMENTS, TO AGFA ANSCO CORPORATION, OF BINGHAMTON, NEW YORK, A CORPORATION OF NEW YORK PHOTOGRAPH IO FILM WITH VISIBLE REPRODUCIBLE INSCRIPTIONS Application filed October 29, 1927, Serial No. 229,791, and in Germany March 16, 1927.

The present invention relates to photographic films with opaque inscriptions upon the rear side of the support and to a process of preparing the same. Its object is to provide a film with the customary continuous signsand symbols indicating the name of the producing firm and the length of the film outside of the picture areas more particularly it relates to anink useful in im rinting continuously photographic raw fi m in the course of its manufacture.

We have found that the raw film can advantageously be provided with inscriptions capable of being printed by exposure to light onto light sensitive layers by lmpressing the letters and symbols upon the rear side of the supporting layer for the sensitized la er, by using for printing a dye solution whic penetrates into the interior of the supporting layer and dries .in a few minutes. For the purpose of printing on film, these two features, viz. penetration of the solution into the support and high drying speed, are essential in order that the printin rocess can be carried out continuously an t at the impression may not be damaged by the usual after-treatment of motion picture film with polishing solvents. Various processes have been suggested for printing on celluloid, but since they never related to photographic raw film, the above mentioned two features have hitherto been neglected. Therefore most ofthe printing solutions known heretofore are characterized-besidesother disadvanta es by a very slow drying speed. It takes ours for an impression roduced by means of the hitherto known so vents on celluloid to become dry.

It has already been proposed to use a solution of printing ink in a low boiling, i. e. highly volatile, solvent. In this case the drying speed is increased, but the other essential feature, the fastness of the finished impression against any polishing treatment,

. depending on the penetration of the printing solution into the support, is neglected.

For the present purpose we have found that there should be employed solutions of dyes in slowly evaporating solvents which, however, are solvents or swelling agents for the supporting layer and which are able to penetrate into the latter. In this way the liquid when printed u on quickly disappears from the surface of t e support, because it penetrates into the inner strata of it. Hence it dries immediately. On the other hand the dye dissolved in the solution is thus carried into the inner parts of the sup ort, when the solvent soaks in, and thus the nished impression is located at a distance below the surface of the sup ort and therefore is well protected against eing spoiled by any solvents which may be applied to the film later on. By this invention the time required for drying is very much decreased.

As a slowly evaporatin solvent to repare the dye solution we use a erivative o a polyvalent aliphatic alcohol, and we prefer to use glycol acetate. Such a dye solution is more viscous than a solution in alcohol or acetone. The increased viscosity, however, is of advantage in obtaining a sharp impression. The slowly evaporating solvent may be mixed with a readily evaporating one, which increases the solubility of the dye without decreasing the drying speed.

This process for numbering films has the advanta e that there is provided a longitudinal inscri tion which is visible prior to exposure and evelopment, and that the lightsensitive layer, after being applied to its support, is not subjected to any further treatment, as the impressions are formed on the rear side of the support.

The invention is performed, e. g., in the following way: raw motion picture film with a nitrocellulose support is imprinted on the rear side of the support, after having been cut and perforated, with a saturated solution of cerasine-red in glycol acetate. In this case the glycol acetate, being a good solvent for the dye, penetrates quickly into the inner strata of the film, whereby the dye, likewise, is carried into the inner parts of the film. Other solvents, capable of dissolving the dye and swelling or dissolving the support and carrying the dye into the interior parts of the film, may likewise be used and are considered to be equivalents of glycol acetate in this respect and to be within the scope of the claims. A photographic film provided on the rear side with mscriptions by means of the said dye-ink may be olished as usual in the hotographic film in ustry; it may be expose developed and finished in the usual iuanner without fading of the impressed sym- The invention is illustrated b means of the accompanying drawing in w ich Fig. 1 shows on. an enlarged scale a length of film exhibiting imprints on the margin. Figs. 2 and 3 represent sections of this film along the line AB and along the line C-D, respectively. Fig. 3 shows how far thedye solution forming the imprint penetrates into the body of the film.

What we claim is:

1. As an ink for continuous printing on photographic film strips, a mixture containmg a dyestufl' and glycol acetate. 7

2. As an ink for continuous printing on photographic film strips, a solution of cerasine-red and glycol acetate.

3. As a new article of manufacture, a

photographic film bearing on the rear side opaque impressions resistant to superficial liquid treatment and produced by means of an ink-containing a dyestufi and glycol acetate.

4. As a new article of manufacture, a photographic film bearing on the rear side opaque impressions resistant to superficial liquid treatment and produced by means of a solution of cerasine-red in glycol acetate.

In testimony whereof, we aifix our signatures.

HERMANN LUMMERZHEIM. EDUARD SCHNITZLER.

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