Improvements in the Production of Indigo on the Fibre.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in the Production of Indigo on the Fibre.
I, GEORGE WILLIAM JOHNSON, of 47, Lincoln's Inn Fields, in the County of
London, Patent Agent, do hereby declare the nature of this invention (which
has been communicated to me from abroad by Kalle & Co., of Biebrich-on-Rhine,
in the German Empire) to be as follows:-
Hitherto in using for the production of indigo on vegetable fibre the indigo
salt for which Letters Patent No. 4287 dated 27th February A.D. 1893 were
obtained on a communication from my foreign correspondents, the goods after
having been impregnated with the indigo salt were treated with caustic soda lye.
My foreign correspondents have now found that the production of indigo on
the fibre by means of the said indigo salt may be effected in the following
manner.
The indigo-salt is perfectly mixed with a suitable thickening and an excess of
caustic soda lye is added to this mixture whilst agitated and if necessary cooled.
The goods are printed with the paste prepared in this manner dried steamed for
some time, and washed. In carrying out the steaming process it is of great
advantage to exclude the air as completely as possible which can be done for
example, by quickly passing a great amount of steam through the steaming
apparatus. If a further reducing agent be added to the printing paste the time
necessary for the steaming process may be shortened. The same is the case if
the printed goods be steamed without back cloth and without being wrapped up.
EXAMPLE.
0.7 kilos of indigo salt dissolved in 1.3 litres of water, are stirred into 2.5 kilos
of British-gum thickening. 5.5 kilos of caustic soda-lye (of 400° Bé) are then
slowly added to this mixture the mass being stirred well and kept cool. The
goods are printed with the paste so obtained, dried steamed without back cloth,
or wrapper, for seven minutes washed, passed through acidulated water and
washed again. The blue obtained in this manner is bright with a reddish tinge.
By proceeding according to this invention the indigo salt is utilized to a much
greater extent and therefore produces much deeper shades than by the old
method whilst the shades are as bright and even, and the indigo-salt can be
combined for its application in cloth printing, with any steam colour, which
combination was impossible under the old method.
Dated this 13th day of Anril 1899
J
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.

page_text: COMPLETE SPECIFICATION.
Improvements in the Production of Indigo on the Fibre.
I, GEORGE WILLIAM JOHNSON, of 47, Lincoln's Inn Fields, in the County of
London, Patent Agent, do hereby declare the nature of this invention (which
has been communicated to me from abroad by Kalle & Co., of Biebrich-on-Rhine,
in the German Empire) and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement:-
Hitherto in using, for the production of indigo on vegetable fibre, the indigo
salt for which Letters Patent No. 4287 dated 27th February A.D. 1893 were
obtained on a communication from my foreign correspondents, the goods after
having been impregnated with the indigo salt, were treated with caustic soda lye.
My foreign correspondents have now found that the production of indigo on
the fibre by means of the said indigo salt may be effected in the following
manner.
The indigo salt is thoroughly mixed with a suitable thickening and an excess of
caustic soda lye is added to this mixture whilst agitated and, if necessary cooled.
The goods are printed with the paste prepared in this manner, dried steamed for
some time and washed. In carrying out the steaming process it is of great
advantage to exclude the air as completely as possible which can be done, for
example, by quickly passing a great amount of steam through the steaming
apparatus. The same is the case if the printed goods be steamed without back
cloth and without being wrapped up.
EXAMPLE.
0.7 kilos of the indigo salt, dissolved in 1.3 litres of water, are stirred into 2.5 kilos
of British-gum thickening. 5.5 kilos of caustic soda-lye (of 40° Bé) are then
slowly added to this mixture, the mass being stirred well, and kept cool. The
goods are printed with the paste so obtained, dried steamed without back cloth,
or wrapper, for seven minutes washed, passed through acidulated water, and
washed again. The blue obtained in this manner is bright with a reddish tinge.
By proceeding according to this invention the indigo salt is utilized to a much
greater extent and therefore produces much deeper shades, than by the old
method, whilst the shades are equally bright and even and the indigo-salt can be
combined, for its application in cloth printing, with any steam colour, which
combination was impossible under the old method.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is:-
-
1. The production of indigo on the fibre by preparing a paste by mixing a
concentrated solution of indigo salt (bisulphite compound of ortho nitro phenyl-
lacto-ketone) with a suitable thickening and then with an excess of caustic soda
lye and printing the goods therewith and steaming the goods after drying them,
in such a manner that the air is excluded as much as possible substantially as
herein before described.
2. The production of indigo on the fibre as hereinbefore described in the fore-
going example.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.