DE3578C - Photolithographic transfer paper with associated transfer printing ink - Google Patents

Description

1878.

Class 57.

JACOB HUSNIK in PRAGUE. Photolithographic transfer paper together with the associated transfer printing ink.

Patented in the German Empire by the io. May 1878.

A. Paper.

Take 1 part of the finest gelatin, 24 parts of water, and for every hundred parts of the solid gelatin, add one part of dissolved chrome alum, filter, and pour the liquid into a large zinc vessel, which is filled with four to five small petroleum flasks under the vessel and can be regulated at will, is slightly warmed; the degree of heat of the liquid should be only 34 ⁰ R.

After the surface of the same is cleaned of foam, the paper becomes sheet-wise with one side immersed and hung to dry. A smooth piece of paper is used for this. If the paper is dry, it will bathed it again in the same solution, but with the one at the top when it was first hung Side down, for the liquid to run off. You can also do this by the arc Dipping bypass and an endless paper in rolls, which under one in the Gelatin solution immersed roller runs in a gelatin solution of 1 part gelatin and Pull away 14 parts of water (also added alum), whereby the double immersion is saved.

When the paper is dry for the second time, it becomes a mixture of 1 part of albumen and bathed two parts of water again, in such a way that it is done with the prepared side only floats on the liquid.

The paper is then hung up to dry again and is then ready.

The greatest advantage and further special peculiarity, however, lies in the chromium salt bath, which is used to sensitize the paper, and which consists of 1 part chromium salt, 14 parts water, and 4 parts alcohol. The spirit does not allow the albumen to separate from the paper, since it is insoluble in the spirit. If one were only to use a water-based bath, the protein would peel off the paper. The albumen but an important one, because it is soluble in the unexposed areas and, together with water color, with which the exponirte paper is coated goes away; so that only the lines on those points where _the: albumen has become insoluble, remain seated together with the color and produce the drawing suitable for transfer printing.

The gelatin forms a firm, smooth base that is insoluble in cold water and also cannot be rubbed away. The combination of the gelatin layer with the upper one is new Protein layer, as well as the alcohol-containing chromium salt bath.

B. The transfer ink.

The color that is used here should firstly be extremely extensive, so after wiping them off completely with a soft cloth a fairly intense, visible tone remains that allows the developed image to be seen, secondly be very bold to produce a bold, expressible image after it has been almost completely wiped off give.

These two properties are achieved by the Berlin blue, which in the dose one fine letterpress ink is rubbed in linseed oil veneer and added. The fat exists simply made of sebum and wax.

The color is also supposed to be a little firm to withstand the friction, and this is what you achieve by adding rosin, which after evaporation of the turpentine is quite a bit runs solid residue.

The mixing ratio is as follows:

20 parts of the finest printing ink

(Chalk paint),
50 parts wax,
40 parts of tallow,
35 parts rosin,
210 parts of turpentine spirit,
30 parts finest Berlin blue stirred into dough.

First the paint is melted, then the wax and rosin, then the sebum is added and finally the Berlin blue and the turpentine spirit.