DE5298A - Fast tanning process using alum and zinc, chromic acid salts, potassium ferrocyanine, barium chloride and other ingredients - Google Patents

Description

1878.

Dr. CHRISTIAN HEINZERLING in BIEDENKOPF.

Process of rapid tanning when using alum and zinc, chromic acid salts, Ferrocyane potassium, chlorobarium and other ingredients.

Patented in the German Empire on November 3, 1878.

The raw hides are depilated and swollen according to the well-known methods. They are then placed in a solution of acidic chromate of potash or of acid of chromic acid of soda, or of acidic chromic acid Magnesia and alum or sulfuric alumina and sodium chloride and run them in it lie for a shorter or longer period of time, depending on the type of skin.

Instead of bringing the blokes directly into this solution, one can also first put them into a five to one Put ten percent alum solution, to which zinc dust or cut zinc sheet is added. When the zinc acts on the alum, amorphous alumina is deposited, which is deposited on the fiber.

After the skins have been exposed to the alum-zinc solution for a longer or shorter period of time, depending on their nature has exposed, they are brought into the above-mentioned solution of acidic chromic acid Potash or soda, etc., the degree of concentration of which depends on the nature of that to be tanned Hides straighten.

After the skins have been in the solution of chromium salts, alum, etc. for a few days a few percent of potassium ferrocyanide or potassium ferricyanide are added to this solution; but these substances can also be added at the beginning of the operation.

For some types of leather, the treatment with ferrous or ferrous cyanide is not necessary. Appropriate is this treatment especially for upper leather, which is to be made black.

In order to fix the tannins on the skins treated in the manner described above, the latter are expediently in a solution of either chlorobarium or acetic acid lead oxide or soaked in soap for a short time. The skins can be dried in the usual way Wise.

The smoothed, still moist skins can be greased or lubricated like tanned leather will. For this purpose the fat can be milled in, or the skins can be dipped for a while in stearin, paraffin, chrysene, or naphtha or similar substances which have previously been dissolved in gasoline, photogen or similar substances. A little carbolic acid or thymol is added to these substances and then greased, if necessary necessary as usual.

The new leather is said to be completely waterproof, significantly more supple, more durable and more waterproof to be as tanned leather. The manufacturing costs should be significantly lower, as with the tanning process.

Claims (6)

Patent Claims: 1. The treatment of raw hides with alum and zinc, the latter using alum in amorphous alumina decomposes, which is then deposited on the fibers of the skin. 2. The use of potassium ferrocyanide or potassium ferricyanide as an additive in tanning and finishing the skins. 3. The use of chlorobarium, acetic acid lead oxide and soap dissolution for Fixation of the above-mentioned substances on the fibers of the skin. 4. The use of the acidic and neutral chromium salts mentioned above in conjunction with Alum and sodium chloride and the treatment of the hides tanned with them with a solution of paraffin and other hydrocarbons or of stearin and other fats, in Gasoline, photogen, petroleum ether and other substances dissolved. 5. The process for tanning leather in its entirety as described above. 6. The leather produced by the process described.