Improvements in the Production of Discharge Effects on Indigo.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in the Production of Discharge Effects on Indigo.
I, BENJAMIN WILLCOX, of 47 Lincoln's Inn Fields, in the County of London,
Chartered Patent Agent, do hereby declare the nature of this invention (which
has been communicated to me from abroad by the Badische Anilin & Soda
Fabrik, of Ludwigshafen-on-Rhine, in the Empire of Germany) to be as
follows:
The most commonly used methods of producing discharge effects on goods,
which have been dyed in the vat with indigo, consist in printing an oxidizing
discharging mass onto the goods. Coloured discharge effects can only be pro-
duced by such colouring-bodies as for instance chrome-yellow, cinnabar, lead-
lakes of the eosines and the like, which are added to the discharging mass, or
are formed in the same, and which have to be fixed on the fibre by means of
albumen, or a similar agent. It has been hitherto impossible to use, for this
purpose, coal-tar colouring-matters dissolved in the discharging mass, since they
are destroyed by the oxidizing agent.
My foreign correspondents have discovered that it is possible to produce with
aniline-dyes most beautiful coloured discharge effects on an indigo ground by
employing a reducing discharging mass, containing acetine and also when desired
the coal-tar colouring-matter. The said acetine was first introduced by my
foreign correspondents into the art of dyeing and printing and is protected under
Letters Patent No. 6631 of 1886 as a dissolving agent for aniline-colouring-
matters when used in printing.
The present invention is of great importance in two directions, it not only
opens, for the employment of a series of aniline-dyes, a new field from which
this series has hitherto been excluded, but it also makes it possible to produce
indigo dyed goods with effects which are new or such as have hitherto only been
produced in a much more difficult and expensive manner.
As reducing agent a mixture of zinc-dust and sodium bisulphite is preferred.
Without the addition of aniline-colouring matter the discharging mass con-
taining acetine produces a pure white shade on an indigo-ground.
The following examples will serve to further illustrate the nature of the inven-
tion but I do not limit myself to the details.
ht
Dissolve about thirty parts of primuline in about two hundred and ten parts
of warm British-gum thickening (containing about three hundred and fifty parts
of British-gum in one litre of water) and about one hundred and fifty parts of
acetine. Cool, and add, slowly, avoiding any rise of temperature, about four
hundred and sixty parts of very finely sifted zinc-dust, and then about one hun-
dred and fifty parts of a sodium bisulphite solution (containing about forty

page_text: Print the dry goods previously prepared with tannin, with a mixture of the
following composition;-about fifteen parts of safranine T extra, about two
hundred and twenty-five parts of British-gum thickening, about one hundred and
fifty parts of acetine, about four hundred and sixty parts of zinc-dust, and about
one hundred and fifty parts of a sodium bisulphite solution (containing about 40%
Na H SO). Print the mass upon the goods and dry, steam as above described,
pass through a weak sulphuric acid bath, to which two parts of tartar emetic
acid per one thousand parts can with advantage be added, wash and dry.
EXAMPLE 3.
GREEN EFFECT.
The goods dyed with indigo are prepared with tannin, and a mass prepared in
the following manner is printed upon them; mix a solution of about twenty parts
of primuline dissolved in about one hundred parts of British-gum thickening
and about one hundred and fifty parts of acetine with a solution of about six
parts of nile-blue A, dissolved in about one hundred and fourteen parts of gum-
water (containing one part of gum-arabic to one part of water), cool the mixture,
add about four hundred and sixty parts of zinc-dust and about one hundred
parts of a sodium bisulphite solution (containing about 40% Na H SO3) and treat
as described in Example 2.
EXAMPLE 4,
WHITE EFFECT.
Print upon the goods about four hundred and sixty parts of zinc-dust, about
two hundred and forty parts of gum water, about one hundred and fifty parts
of acting and one hundred and fifty nouts of a caulium hiculuhita colution
Improvements in the Production of Discharge Effects on Indigo.
I, BENJAMIN WILLCOX, 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 the Badische Anilin and Soda Fabrik, of

page_text: Ludwigshafen on Rhine, in the Empire of Germany) and in what manner the
same is to be performed to be particularly described and ascertained in and by
the following statement:-
:-
The most commonly used methods of producing discharge effects on goods,
which have been dyed in the vat with indigo consist in printing an oxydizing
discharging mass onto the goods. Coloured discharge effects can only be pro-
duced by such colouring bodies as for instance chrome-yellow, cinnabar, lead-
lakes of the eosines and the like, which are added to the discharging mass
are formed in the same and which have to be fixed on the fibre by means of
albumen or a similar agent. It has been hitherto impossible to use for this
purpose coal-tar colouring matters dissolved in the discharging mass, since they
are destroyed by the oxydizing agent.
or
My foreign correspondents have discovered that it is possible to produce with
aniline-dyes, most beautiful coloured discharge effects on an indigo-ground by
employing a reducing discharging mass, containing acetine and also coal tar
colouring-matter which of course must be stable against the reducing agent
under the conditions herein used. Acetine was first introduced into the art of
dyeing and printing by my foreign correspondents, and is protected under Letters
Patent No. 6631 of 1886 as a dissolving agent for aniline colouring matters when
used in printing.
The present invention is of great importance in two directions, it not only
opens, for the employment of a series of aniline-dyes, a new field from which
this series has hitherto been excluded, but it also enables indigo dyed goods to
be produced with effects which are new, or such as have hitherto only been pro-
duced in a much more difficult and expensive manner.
As reducing agent a mixture of zinc dust and sodium-bisulphite is preferred.
Without the addition of aniline-colouring matter the discharging mass contain-
ing acetine produces, as my foreign correspondents have further discovered, a
pure white on an indigo-ground.
The following examples will serve to further illustrate the nature of the inven-
tion and the manner in which it can be performed but I do not limit myself to
the details The parts are by weight.
Dissolve about thirty parts of primuline in about two hundred and ten parts
of warm British-gum thickening (containing about three hundred and fifty parts
of British-gum in one liter of water), and about one hundred and fifty parts of
acetine. Cool and add slowly avoiding any rise of temperature, about four
hundred and sixty parts of very finely sifted zinc dust, and then about one hun-
dred and fifty parts of a sodium bisulphite-solution (containing about forty
per cent. of sodium bisulphite Na H SO3). Print the mass upon the goods, dry,
steam for an hour, at half an atmosphere of additional pressure, put the goods
in a weak acid-bath (containing half a part of concentrated sulphuric acid per
thousand parts of water) wash and dry.
In employing basic dyestuffs, such, for instance as safranine, methylene-blue,
nile-blue, phosphine and the like, it is preferable to prepare the indigo-
dyed goods with tannin before printing so as to obtain shades very fast against
washing. This can be effected by impregnating with a two per cent. tannin-
solution.

page_text: dred and twenty five parts of British-gum thickening, about one hundred and
fifty parts of acetine, about four hundred and sixty parts of zinc dust, and about
one hundred and fifty parts of a sodium-bisulphite solution (containing about
forty per cent. of sodium bi-sulphite Na H SO3). Print the mass upon the goods
and dry, steam as above described, pass through a weak sulphuric acid-bath, 5
to which two parts of tartar emetic per one thousand parts can with advantage
be added, wash and dry.
GREEN EFFECT..
The goods dyed with indigo are prepared with tannin and a mass, prepared in
the following manner, is printed upon them. Mix a solution of about twenty
parts of primuline dissolved in about one hundred parts of British-gum thicken-
ing, and about one hundred and fifty parts of acetine, with a solution of about
six parts of nileblue A, dissolved in about one hundred and fourteen parts of
gum-water (containing one part of gum-arabic to one part of water) cool the
mixture, add about four hundred and sixty parts of zinc-dust, and about one
hundred parts of a sodium-bisulphite solution (containing about forty per cent.
of sodium bisulphite NaHSO,) and treat as described in the preceding Example 2.
EXAMPLE 4,
WHITE EFFECT.
Print upon the goods about four hundred and sixty parts of zinc-dust, about
two hundred and forty parts of gum-water, about one hundred and fifty parts
of acetine, and one hundred and fifty parts of a sodium bisulphite solution (con-
taining about forty per cent. of sodium bisulphite Na H SO,) dry, steam as above
described, acidify, wash and dry.
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, white discharge effects on an indigo ground by means
of a reducing discharge mass consisting of zinc dust and bisulphite of sodium
and containing acetine substantially as herein before described.
2. The production of coloured discharge-effects on an indigo ground by means
of a reducing discharge mass consisting of zinc dust and bisulphite of sodium
and containing acetine with the addition of an aniline colouring matter stable
against the reducing agent substantially as herein before described.
3. The several processes for producing discharge effects on an indigo ground;
substantially as hereinbefore described under the foregoing examples.
Dated this 26th day of May 1898.
JOHNSONS & WILLCOX..
47, Lincoln's Inn Fields, London, W.C., Agents.