Improved Process for Treating Hides.
Year: 1899

page_text: Date of Application, 19th Jan., 1899
Complete Specification Left, 7th Oct., 1899-Accepted, 13th Jan.,
1900
I, LEONHARD FRIEDLÄNDER, of Berlinerstrasse, 7/11, Rixdorf, near Berlin,
Germany, Manufacturer, do hereby declare the nature of this invention to be as
follows:
This invention relates to a process for treating hides either in the raw state
before tanning, or in the tanned state, and one of the objects of the invention
is to increase the value of low quality hides which by the process are made better
and stronger.
The process consists in treating the hides in a solution of resin in sulphuret of
carbon or hydrocarbon, as for instance, petroleum or benzine in which. resin.can
be dissolved.
Sulphuret of carbon possesses the peculiar property of causing the elastic fibres
of the hides to swell out so that the resin molecules penetrate into or amongst
the outer layers of the same and form an elastic coating:
In the case of raw hides the penetration of the resin molecules into the fibres
causes the albumenous substances of the same to undergo a change that prevents
injury to the elasticity of the hides in the tanning process.
In the case of tanned hides the resin passing into the fibres fills up the inter-
stices between the same which are either empty or filled with the tanning prepara-
tion which the process causes to fall out or dissolves.
Dated this 19th day of January 1899.
CAPITAINE & VON HERTLING,
15, Tooks Court, London, E.C.,
Agents for the Applicant.
Improved Process for Treating Hides.
I, LEONHARD FRIEDLÄNDER, of Berlinerstrasse, 7/11, Rixdorf, near Berlin,
Germany, Manufacturer, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
The process of this invention has for object to improve the quality of and
render more durable hides or leather and more especially those kinds from
which goods of an inferior quality and of low commercial value are now obtained.
The process may be performed in two ways, the one before the albuminous
material is transformed into leather and the other after this has been done. In
r 077

page_text: each case the chemical and physical action obtaining in the process, and the
results, vary according to the nature of the material treated.
In the treatment of hides or skins still containing albuminous substances, these
are placed according to the effect desired either in a solution of resin in carbon
disulphide or of resin in hydrocarbons of the kind, petroleum for instance, in
which resin is soluble, the proportions being about 50 lbs. of resin to 100 lbs. of
the solvent but varying somewhat according to the properties of the material
treated.
It is known that the corium of hides or skins is composed of interlaced con-
nective tissue drawn through by elastic fibres upon which the elasticity of the
hide depends. This property of the fibres is given by a substance, elastin, of
which the greater portion of said fibres is composed and which greatly resists
the action of chemicals and which is scarcely overcome by anything but tanning
preparations so that after treatment with these the elastic fibres have lost their
specific property. In the process, the carbon disulphide has the peculiar property
of causing the elastic fibres to swell up so that resin molecules enter into the
outermost layers of the fibres and produce an elastic covering which protects
the deeper layers of the fibres against the action of the tanning preparations.
Further, the carbon disulphide also acts upon the connective tissue or woven
like binding fibres but only to a limited extent and upon the outer layers of the
same. Thereupon the albuminous substances of the connective tissue undergo a
transformation, without, as in the case of the elastic fibres, the tanning process
proper being in the least hindered.
In performing the process with hydrocarbons, the several kinds of which shew
only a slight difference in their action, there is no particular effect produced on
the elastic fibres but there is upon the albuminous substances of the connective
tissue although not to the same extent as when disulphide of carbon is employed,
the hydrocarbon being more particularly adapted for use in the production of a
particularly soft material.
With respect to the second way of performing the process, namely, the treat-
ment of the already tanned hide with a solution of resin in carbon disulphide or
in a hydrocarbon the cause of the difference between good and bad leather may be
referred to. In this it is necessary to consider firstly the anatomical con-
struction of the corium and secondly the chemical action of the tanning stuff.
The fibres of the connective tissue are not all equally close together the clefts
and lymph spaces which extend through the interlaced fibres appear under the
miscroscope almost like network, the meshes being either empty, that is, con-
taining air only, or filled with tanning stuff which has only a slight hold and
which in the treatment falls out or is dissolved by the moisture taken by capillary
force into the microscopically small spaces. This suction force is especially
useful in the process as it takes up in the most effective manner the carbon
disulphide or, but in a lesser degree, the hydrocarbon, so that the empty spaces
filled with resin or with the tanning stuff are so bound together that said resin
or tanning stuff cannot be dissolved.
Leather of inferior quality is produced when the tanning process is not con-
tinued long enough, so that the product is irregular and some components of
the connective tissue, more especially those not containing viscous substances
which are difficultly tanned, are not transformed into leather. Chemical experi-
ments, chiefly in relation to the carbon disulphide saturated with resin, have
shewn that this solution, when it has acted for a length of time on albumen,
produces a specific effect and that the product thereby obtained is an intimately
mixed substance of such a property that the albumen components thus treated
are by no means inferior to those that are tanned.
From the above it will be seen that in the second way (after tanning) of per-
forming the process the operation is longer than in the first way and that the
product thereby obtained will be stronger and more durable than that obtained
in the first way.

page_text: Further a number of other operations, for instance that of the hydrocarbon on
the cementing substances of the connective tissue, are brought about but which
for the purpose of this invention it is unnecessary to describe.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
The process of treating hides and leather, for the purpose of rendering the
same stronger and more durable, with a solution of resin in carbon disulphide
or in hydrocarbons in which resin is soluble, substantially as described.
Dated this 7th day of October 1899.
CAPITAINE & VON HERTLING,
15, Tooks Court, London, E.C.,
Agents for the Applicant.