IMPROVEMENTS IN EMPLOYING CERTAIN PREPARATIONS OF
Year: 1871

page_text: LETTERS PATENT to Paul Schützenberger and Felix de Lalande, of
Rue des Ecoles, No. 40, at Paris (France), Chemists, for the
Invention of "IMPROVEMENTS IN EMPLOYING CERTAIN PREPARATIONS OF
"
G
Sealed the 22nd May 1872, and dated the 13th December 1871.
PROVISIONAL SPECIFICATION left by the said Paul Schützenberger
and Felix de Lalande at the Office of the Commissioners of Patents,
with their Petition, on the 13th December 1871.
We, PAUL SCHÜTZENBERGER and FELIX DE LALANDE, of Rue des
Ecoles, No. 40, at Paris (France), Chemists, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN EMPLOYING CERTAIN PREPARATIONS
OP INDIGO IN PRINTING AND DYEING," to be as follows:-

page_text: pression by means of subsequent vaporisation and oxidation when
employed in the presence of certain compounds, more particularly
those of which the base is susceptible of giving with white indigo a
soluble compound, such as the salts of potash, soda, ammonia (and its
derivatives by substitution), lime, baryta, strontia, lithia, and par-
ticularly salts with alkaline or weak acid reaction. We precipitate for
instance the white indigo from any suitable vat (such as a vat of vitriol,
of tin, of orpiment, or of hydrosulphites), by the addition of an acid or
a salt. This precipitate, drained and filtered if necessary, is mixed with
one or more of the above-named compounds in proportions which
vary according to the nature of the compound and the richness of the
white indigo paste or indigotate; thus for a paste containing one-seventh
part of indigo we take of the said paste 5 parts, of bi-carbonate of soda
about one part.
These proportions are entirely arbitrary, and the bi-carbonate of soda
given as example can be replaced by one of the other substances above
named, or by a mixture of such substances, by alkaline or ammoniacal
carbonates or bi-carbonates, by carbonate of lithia, by cyanide of
potassium, by soluble borates or phosphates, or a mixture of these
bodies. It may also be advantageous to add to the white indigo paste
a reducing agent in case it is too oxidisable. The colour thus produced
thickened in any desired manner, either cold or hot, according to the
nature of the salts added, is printed on a tissue, dried and evaporated,
and then the tissue is subjected to oxidation either in the air or in
running water, or by exposure to a chromate or other oxidating agent.
When necessary it is in the first place passed through an acid bath.
After washing the colour remains fixed on the tissue with a tint of
greater or less intensity, according as the paste applied in printing has
been more or less rich in indigo.
Moreover, by printing with the paste of white indigo or of indigotate
mixed or not in varied proportions with one of the above-named salts
or with a mixture of them, and by thickening with albumen, caseine,
gluten, or other substance usually employed, by drying, evaporating,
oxidating in air or water or by an oxidating bath, there is obtained on
the tissue a blue colour with a coppery glance of peculiar character.
We have also observed that by causing bydrosulphurous acid or
hydrosulphites to react at high or low temperatures on powdered

page_text: indigo in presence of an alkaline or alkaline earth base, or of an alkaline
substance, a very rapid reduction of the indigo is obtained, thus allowing
the rapid production of a vat of more or less concentrated dye. This
vat may be employed for various dyeing operations after suitable
dilution. We employ it also with advantage for preparing the pre-
cipitate used for printing according to our method.
For producing a vat, for example, we take bruised indigo, 2lbs. ;
water in sufficient quantity to hold the indigo in suspension; con-
centrated hydrosulphite of soda, from 6 to 10lbs., according to its
strength.
By the term "hydrosulphurous acid" we mean the liquid obtained
by the action of an aqueous solution of sulphurous acid on a metal such
as iron or zinc. Concentrated hydrosulphite of soda or potash is
obtained by the action of iron or zinc on a concentrated solution of
bisulphite of soda or potash.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Paul Schützenberger and Felix de Lalande in the
Great Seal Patent Office on the 7th June 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, PAUL
SCHÜTZENBERGER and FELIX DE LALANDE, of Rue des Ecoles, No. 40,
at Paris (France), Chemists, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirteenth day of December, in the
year of our Lord One thousand eight hundred and seventy-one, in
the thirty-fifth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto us, the said Paul Schützenberger and Felix
de Lalande, Her special licence that we, the said Paul Schützenberger and
Felix de Lalande, our exccutors, administrators, and assigns, or such
others as we, the said Paul Schützenberger and Felix de Lalande,
our executors, administrators, and assigns, should at any time agree

page_text: with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make,
usc, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN EMPLOYING CERTAIN PREPARATIONS OF INDIGO IN PRINTING
AND DYEING," upon the condition (amongst others) that we, the said
Paul Schützenberger and Felix de Lalande, our executors or adminis-
trators, by an instrument in writing under our or their hands
and seals, or under the hand and seal of one of us or them, should
particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the
same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that we, the said Paul Schützenberger and Felix
de Lalande, do hereby declare the nature of the said Invention, and in
what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement thereof, that is
to say :-
We have discovered that the precipitate of white indigo or of
indigotate obtained by precipitation from any solution of indigo by
means of an acid or a salt can after printing be fixed on a tissue by
exposure to vapor and subsequent oxydation when certain compounds
are present, especially those which have bases capable of dissolving
white indigo, such as salts of potash, soda, ammonia, lime, baryta,
strontia, or magnesia, and especially salts having an alkaline or feebly acid
reaction. We precipitate the indigo from any vat or solution, such as
those with vitriol, tin, orpiment, or hydrosulphites. This precipitate,
drained and strained if necessary, is mixed with one of the substances
named above in proportions which may vary according to the nature
of the added substance and the richness of the paste of indigo or
indigotate. Thus, for example, for a paste containing one-seventh of
indigo we take five parts of paste and one part of bi-carbonate of soda.
The colour thus formed, with the addition of such a quantity of
thickening as may be necessary to obtain the desired shade, is printed
upon tissue, which is then dried, exposed to vapour, and then to
oxydation either in the air, or in running water, or to a chromate. It
may be useful in the first place to pass the tissue through an acid bath.

page_text: It should be exposed to the action of the vapour only for a very short
time; long exposure destroys a portion of the indigo.
Moreover, by printing with the paste of white indigo or of indigotate
mixed or not in varied proportions with one of the above-named salts or
with a mixture of them, and by thickening with albumen, cascine,
gluten, or other substance usually employed, by drying, exposing to
vapor, oxidating in air or water, or by an oxidating bath, there is
obtained on the tissue a blue colour with a coppery glance of peculiar
character.
We have also observed that by causing hydrosulphurous acid or
hydrosulphites to react either at a high or a low temperature upon
powdered indigo in presence of a base of an alkali or alkaline earth, or
of an alkaline substance, a very rapid reduction of the indigo is obtained,
which gives great facility for producing a vat or solution more or less
concentrated.
For preparing a vat or solution there may be taken, for example,
about 2 lbs. of bruised indigo, water sufficient to hold the indigo in
suspension, and from 8 to 10 lbs. of concentrated hydrosulphite of
soda, or a quantity sufficient for thoroughly reducing the indigo, and
alkali, such as soda, potass, ammonia, lime, or other alkaline earth in
sufficient quantity to dissolve the reduced indigo. This vat or solution
may be employed like various known solutions for different dyeing
operations after having been suitably diluted. We employ it for pre-
paring the precipitate of white indigo, which we use for printing as
above described, and which may also be used for preparing indigo vats
or solutions. This vat or solution after being thickened may be printed
on tissue with marked advantage; for the hydrosulphite which it
contains in excess, and which we increase in this particular case, reduces
in a continuous manner the indigo, which becomes oxidized on contact
with the air, so that the colour to be printed maintains constantly the
same concentration of dissolved colouring matter.
To produce a colour for printing we add to the vat or solution
produced as above described a quantity of hydrosulphite of soda which
may be varied, but which may be, for example, 4 to 5 lbs. to the pound
of bluc indigo. It may be useful to neutralize this hydrosulphite by

page_text: an alkali or alkaline earth, such as potash, soda, or lime before adding
it to the vat or solution, employing only the clear liquid. This vat or
solution is then thickened with a suitable quantity of thickening
matter, and the colour is ready for printing. The last step of the
process is completing the oxydation of the white indigo on the tissue by
leaving it for some time in running water and soaping it. The
colour bears, without being notably affected, most of the kinds of
treatment to which other colours are usually subjected.
A similar result is attained by forming a colour with suitable pro-
portions of blue indigo or white indigo paste, alkali, neutralized hydro-
sulphite of soda and thickening. When a colour is mixed with
thickening matter it is well to add at the same time a certain proportion
of hydrosulphite, for example one part to five parts of thickening. The
proportions we have given are not absolutely fixed, the important feature
of this process being the use for the reduction of indigo of the sub-
stances which we call bydrosulphites.
We mean by the term " hydrosulphurous acid" the liquid obtained.
by the action of an aqueous solution of sulphurous acid on a metal,
such as iron or zinc. The hydrosulphite of soda or of potash concentrated
is obtained by the action of iron or zinc on a concentrated solution of
bi-sulphite of soda or of potash, or of other bi-sulphites, at a low or high
temperature.
Having thus described the nature of our Invention, and in what
manner the same is to be performed, we claim,—
First. The production of a fast blue colour by printing with a
thickened paste containing precipitate of indigo or indigotate com-
pounded with an alkaline or feebly acid salt, whose base can dissolve
white indigo (such base being an alkali or alkaline earth), and after
printing exposing to vapor and oxydating, substantially as herein
described.
Second. The production of a blue colour with coppery glance by
printing with a paste thickened with any of the substances usually
employed for fixing and containing white indigo or metallic indigotate
with or without an alkaline salt, substantially as herein described.

page_text: Third. The use for the reduction of indigo and the preparation of its
solutions for dyeing or printing of hydrosulphurous acid or hydrosul-
phites, substantially as herein described.
In witness whereof, we, the said Paul Schützenberger and Felix de
Lalande, have hereunto set our hands and seals, this Third day
of June, in the year of our Lord One thousand eight hundred
and seventy-two.
o Witness,
CH. ARMENGAUD,
Civil Engineer,
PAUL SCHÜTZENBERGER. (L.S.)
FELIX DE LALANDE.
'
(L.S.).
Boulevard de Strasbourg, No. 23,
Paris.