US1397387A

US1397387A - Process for the manufacture of iron-leather

Info

Publication number: US1397387A
Application number: US395146A
Authority: US
Inventors: Rohm Otto
Original assignee: Individual
Current assignee: Individual
Priority date: 1920-07-09
Filing date: 1920-07-09
Publication date: 1921-11-15
Anticipated expiration: 1938-11-15

Description

ocrro Roma, or nenms'ranr, canny.

PROCESS FOR THE MANUFACTURE OF IRON-LEATHER.

No Drawing.

To all whom it may concern:

Be it known that I, O'r'ro RoHM, a citizen of the Free State of Wurttemberg, in the German Republic, residing at Darmstadt, in the State of Hessia, Germany, have invented Improvement in and Relating to a Process for the Manufacture of Iron- Leather, (for which I have filed applications in Germany May 2, 1918; in Czechoslovakia Aug. 19, 1919; in Austria Nov. 22, 1919; in Hunga Nov. 28, 1919; andin Spain March 30, 1920;). and I do hereby declare the following to be a fullfclear, and exact descrlption of the same.

My invention relates to a process for tawing or alutation of skins by means of silicate of iron, in which the skins are acted upon by solutions of iron salts and silicates together,

i. e. in a single tawing bath.

Hitherto for the manufacture of ironleather soluble iron salts for instance basic sulfate of iron or basic ferric chlorid have been used. It has also been proposed to first taw the skins with soluble iron salts and then to ut the iron-leather thus obtained in a so ution containing (besides sebacic combinations) alkaline silicate. In proceeding in this way a part of the iron salt taken up by the skin is first precipitated again and celerated manner.

forms with the alkaline silicate an insoluble silicate of iron. The latter settles upon the skin which'thereby becomes brittle.

According to the new process the skin is acted upon by the silicate of iron during the colloidal state whereby a non brittle iron-leather is obtained in a simple and ac- To this end the skins during tawing with iron salts are brought together with diluted solutions of waterglass.

If in carrying out this process a concentrated Solution of water-glass of 36 B. would be added to a solution of an iron salt, such as ferric chlorid, a separation of insoluble'silicate of iron would take place at once and a tawing with this mixture would be impossible. If however the concentrated solution of water-glass is first diluted for instance with an 810 fold quantity of water and said solution of waterglass added to the solution of ferric chlorid, a separation of silicate of iron does not take place even it up to 4 parts of water-glass a17e added to one part of ferric-chlorid. Moreover the deposit of silicate ofiron Specification of Letters Patent.

Patented Nov. 15, 1921.

Application filed July 9, 1920. Serial No. 395,146.

formed at the be inning of the process is perfectly dissolvef again on stirring.

The solutions of sllicate of iron thus obtamed are, as stated above, especially adapted for the manufacture of ironleather. Against solutions of basic iron salts the said solutions of silicate of iron have the advantage that they very easily penetrate the skin or in other-word very quickly taw.

The lnvention may also be carried out in such a manner that the skin is first brought into the solution of iron salt and after the latter has penetrated the skin the desired quantity of solution of water-glass is slowly added to the same bath.. In this way also the forming of insoluble silicate of iron is prevented.

It has already been stated above that according to the new process up to 4 parts of water-glass may be used with 1 part of iron salt. Depending upon the proportions used leather of different properties is obtained and the more water-glass'is used in proportion to the iron salt the fuller and stronger the leather.

To obtain iron-leather by means of silicate of iron one of the following processes may be used: 7 1

1. To taw 100 kg. of skins a clear solution of silicate of iron is prepared by adding a diluted solution of water-glass to a solution of 10 kg. ferric chlorid in 100 1. water. solution of concentrated water-glas is added and with this mixture the skins are tawed, washed out, fatted if necessary, dried and dressed in a well known manner.

2. 100 kg. of skins are first placed in a solution of 10 kg. of ferric chlorid and 5 kg. of common salt in 100 1. water. After. some time 200-300 kg. of a 10% solution of waterglass are slowly? added to the constantly moving tawing bath. The moving is continued until the skin does not take up any more tawing matter. taken out, washed out with water, fatted if necessary, dried and dressed.

To further improve the properties of the iron-leather thus obtained the same measures may be taken as are used in the other tawing 105 a tawmg by means of formaldehyde, Ac- 110 For instance 200-300 kg. of a 10% The leather is then cording to the present process also the tawing action will be improved by the use of aldehydes for instance formaldehyde and a specially resistant leather is obtained. The aldehyde may be added during any desired stage of the process, z'. 6. before, during or after the tawing explained above.

If these improvements are to be used 2-3 kg. of formaldehyde may be added to the example of the quantity of water-glass given above for the tawing of 100 kg. of, skins. The formaldehyde tawing may however take place before or after the tawing with iron salts.

It may also be stated that before the tawing the skins may be pickled as is usual in tawing with chrome salts. Also the pickling: acid may be added to. the salt :solut1onsdescribed above. By the use of acid in this form the tawing is accelerated and a specially Smooth grain is obtained. 9-

Having-now described and ascertained'the' nature of my invention and the manner in which the same is to be performedInow declare what I claim and desire to secure by Letters Patent of [the United. States is 1. The herein described process for manufacturing iron-leather, consisting in subjecting the skins to a solution ofiron'salts, and

adding a diluted solutionofwater glass' 'to said solution.

name to this specification in the a two subscribing witnesses.

2. The herein described process for manufacturing iron leather, consisting'in subjecting the skins to a solution of iron salts and facturing iron leather, consisting in subjecting the skins to. a tawi'ng solution of iron salts, adding a diluted solution of water glass tothe tawing solution, and adding a solutionof formaldehyde to the tawing soluti0n.-- V

i 5. The herein described process for manufacturing iron-leather, consisting in sub- 1 je'ctingz'the skins to a solution of iron salts, .an'dijadding to said solution ,a solution of water. glass andformaldehyde.

-Intestimony whereof, I have signed my presence of DR. OTTO. R'O'HM.

.v v WILBEIMIYANDRESL