Improvements in the Treatment of Textiles by Means of Ammoniacal Oxide of Copper for the purpose of Rendering same Waterproof and Non-combustible.
Year: 1889

page_text: COMPLETE SPECIFICATION.
Improvements in the Treatment of Textiles by Means of Ammoniacal
Oxide of Copper for the purpose of Rendering same Waterproof
and Non-combustible.
I CARL BASWITZ of the firm of A. Baswitz of Holzmarktstrasse 4 Berlin in the
German Empire Manufacturer do hereby declare the nature of this invention and
in what manner the same is to be performed to be particularly described and
áscertained in and by the following statement :—
The quality of an ammoniacal oxide of copper as a means of dissolving
vegetable fibre has to this day been of slight importance for finishing or dressing
purposes as the fabric which has been treated with such oxide shows no substantial
change in its original textile qualities after the evaporation of the ammonia and the
removal of the hydrate of copper oxide. Its increased power of suction for liquids is
easily remarkable even when the visible pores of the textile are closed by some dissolved
and rehardened vegetable substance which was pressed into the pores by strong
pressure while in a soft state.
But if vegetable parchment is dissolved in ammoniacal oxide of copper and the
textile impregnated with the solution as soon as the ammonia has evaporated the fabric
possesses all the characteristic qualities of parchment. The waste or refuse from
parchment manufactories is suitable for this purpose. Liquids can permeate only by
means of the dialysis.
For this purpose so much hydrate of copper oxide is dissolved in spirit of
sal ammoniac of the specific weight of 91 that there are 30 gramines of copper to
every litre of the solution and then 15 grammes of vegetable parchment must be
added. The mechanical process remains in every respect the same as that described
in the Specification of my Application for Patent dated the 22nd October 1889
No. 16708 and the apparatus therein described may now he employed for my present
improved process. After the textile has been impregnated with the solution of
parchment in ammoniacal oxide of copper the chief thing is to remove the copper
therefrom. Every acid employed for this purpose requires, with the only exception
of acetic acid, a supplemental treatment of the textile with ammonia in order to
absorb the free acid which would otherwise destroy the fabric whilst a part of the
acetic acid would be bound by the copper, another part stop in the fabric and it is
true evaporate but would thereby become expensive and troublesome. Therefore and
for the second purpose to make the textile contain the air which has been withdrawn
during the previous operation a solution of acetate of alumina or the specific weight
of 104 is taken and 100 grammes of sulphate of ammonia p. litre is dissolved
therein in order to hasten the transposition of the hydrate of copper oxide with the
acetate of alumina. A vigorous osmose begins by means of the layer of parchment
lying on both sides of the fabric and the sub-sulphate of alumina-ammonia remains in
the textile whilst valuable acetate of copper passes into solution. At the same time
the presence of the sub-sulphate of alumina-ammonia in the textile effects a lasting
protection against combustion because in any heat this compound supplies the same
non-combustible decomposing products as the sulphate of ammonia and has this
advantage that it cannot be washed out by water.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
The treatment of textile fabrics by means of a solution of ammoniacal oxide of
copper as being novel and peculiar.
1st. The employment of a solution of vegetable parchment in an ammoniacal

page_text: oxide of copper for permeating the textile fabrics substantially as and for the purposes
set forth.
2nd. The employment of exhausting and absorbing apparatus for regaining the
ammonia which are connected with the impregnating box and the drying chamber
and which have for their object the exhaustion of those amoniacal fumes emitted
from the liquid and from the impregnated pieces of the fabric and also the absorption
of same by means of sulphuric acid substantially as set forth.
3rd. The employment of a compound of sulphate of ammonia and acetate of
aluminium for removing the hydrate of copper oxide from the fabric and for
obtaining sub-sulphate of aluminium-ammonia in the fabric substantially as herein-
before set forth.
Dated this 23rd day of December 1889
TONGUE & BIRKBECK,
34, Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicant.