IMPROVEMENTS IN THE PREPARATION OF ARTIFICIAL INDIGO, AND IN THE APPLICATION OF THE SAME TO DYEING, PRINTING, AND MARKING TEXTILE FABRICS AND MATERIALS
Year: 1881

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields, in the
County of Middlesex, Gentleman, for an Invention of "IMPROVEMENTS IN
THE PREPARATION OF ARTIFICIAL INDIGO, AND IN THE APPLICATION OF
THE SAME TO DYEING, PRINTING, AND MARKING TEXTILE FABRICS AND
MATERIALS." A communication from abroad by Adolphus Baeyer, Doctor
of Philosophy and Professor of Chemistry in the University of Munich, in the
Kingdom of Bavaria, Empire of Germany.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at
the Office of the Commissioners of Patents on the 3rd February 1881.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN THE PREPARATION OF ARTIFICIAL INDIGO, AND
IN THE APPLICATION OF THE SAME TO DYEING, PRINTING, AND MARKING TEXTILE
FABRICS AND MATERIALS." A communication from abroad by Adolphus Baeyer,
Doctor of Philosophy and Professor of Chemistry in the University of Munich, in
the Kingdom of Bavaria, Empire of Germany.
In the Specification of Letters Patent granted to me for an Invention of
improvements in preparing coloring matters suitable for dyeing and printing, and
in materials used in the manufacture of the same, and dated 18th March, 1880,
No. 1177, I have described a process for producing so called "artificial indigo" by
submitting orthonitrophenylpropiolic acid to the action of reducing or deoxydizing
agents, such as glucose or similar bodies, in the presence of caustic or carbonated
alkalies or of alkaline earths.
In the Specification of Letters Patent granted to me for an Invention of
"Improvements in Dyeing, Printing, and Marking Textile Fabrics and Materials,"
and dated 30th April 1880, No. 1771, I have described the manner in which the
above said process, may be applied to dyeing, printing, and marking purposes by
producing artificial indigo within the fibre of textile fabrics and materials.

page_text: Now my foreign correspondent has discovered that artificial indigo may be pro-
duced from orthonitrophenylpropiolic acid by replacing the reducing or deoxydizing
agents named in the above recited Letters Patent, such as glucose, milk, sugar, or
similar saccharine substances by the sulphides, sulphydrates, polysulphides, sulpho
carbonates and sulphocarbonic ethers of the alkali metals and alkaline earth
metals, and more especially by the alkaline ethyldisulphocarbonates or xanthates.
My said foreign correspondent has discovered that the said sulphur compounds
possess more powerful reducing or deoxydizing properties than the above mentioned
saccharine agents, and to be capable of effecting the production of artificial indigo
from orthonitrophenylpropiolic acid in the cold or at an ordinary temperature; their
reaction however is perceptibly assisted by heat. The said reagents may be
employed in aqueous or alcoholic solution, but in the case of xanthates being used
my foreign correspondent has observed the desired deoxidation of orthonitro-
phenylpropiolic acid chiefly to proceed after the evaporation of the solvent.
The following is an example of the manner in which this Invention may be
applied to the preparation of artificial indigo:
Orthonitrophenylpropiolic acid is taken and neutralized with a solution of a
caustic or carbonated alkali. A. solution of an alkaline sulphydrate is then added,
and the reaction is allowed to proceed at an ordinary or at an elevated temperature
until the formation of dark colored precipitate appears to be finished. The said
precipitate contains, artificial indigo blue and allied coloring matters and also free
sulphur; it may be collected on a filter, washed with water, and dried, and the
sulphur if desired may then be removed by treatment with bisulphide of carbon or
by any other convenient method. The artificial indigo thus obtained may or may
not afterwards be treated with alcohol or other suitable solvents in order to extract
therefrom purple or red coloring matters allied to indigo blue.
As another example, a mixture of an alkaline salt of orthonitrophenylpropiolic
acid with an alkaline xanthate and with as much water as is required to form a
paste is prepared; the said mixture is then allowed to dry up spontaneously, or the
evaporation of the solvent may be assisted by a moderate heat. The mixture
gradually turns blue, and the reaction is finished when the blue colour no longer
increases in intensity. The dark blue product thus obtained contains in addition to
colouring matters soluble salts or compounds, which may be eliminated therefrom
by repeated washings with water, and the insoluble residue may or may not be
further purified by treatment with suitable solvents, such as bisulphide of carbon,
alcohol, or by any other convenient method.
An example of the manner in which this Invention may be applied to dyeing,
printing, and marking purposes by producing artificial indigo within the fibre
of textile fabrics and materials is as follows:-
For dyeing textile fabrics, yarn, or cloth with artificial indigo, a cold aqueous
solution containing an alkaline salt of orthonitrophenylpropiolic acid and an alkaline
xauthate is prepared, and with the said solution the materials to be dyed are
impregnated. For dark shades a concentrated solution is to be employed, and for
light shades the solution is to be diluted accordingly. The goods are then allowed
to dry and to age at a moderate temperature until the blue colour becomes fully
developed. The textile fabrics and materials thus dyed may then be washed and
dried.
As another example the goods to be dyed are impregnated with the solution of
an alkaline salt of orthonitrophenylpropiolic acid, then dried, and the color
developed by a passage through a hot and concentrated solution of an alkaline
polysulphide. For printing or marking purposes an alkaline salt of orthonitro-
phenylpropiolic acid is mixed with an amount of gum water, starch paste, or any
other suitable thickening proportionate to the depth or shade of color required.
An alkaline xanthate is then added in the cold state, and the whole is well mixed.
The printing colour or marking ink thus prepared ought to be employed without
much delay, as upon standing it is liable to decompose..

page_text: The textile fabric or material may also be first prepared or impregnated
with an alkaline xanthate, and then be printed or marked with an alkaline
salt of orthonitrophenylpropiolic acid, or the latter salt may be applied first, and
then a printing colour or marking ink containing the alkaline xanthate may be
used.
After printing or marking by any of the above described methods the blue
colour becomes developed within the fibre of the textile fabric or material by
mere drying and ageing at a moderate temperature; steaming or heating is not
required. After the artificial indigo is fully produced the goods may be washed
and dried.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Henry Johnson in the Great Seal Patent Office on the
29th July 1881.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN THE PREPARATION OF ARTIFICIAL INDIGO, AND
IN THE APPLICATION OF THE SAME TO DYEING, PRINTING, AND MARKING TEXTILE
FABRICS AND MATERIALS." A communication from abroad by Adolphus Baeyer,
Doctor of Philosophy and Professor of Chemistry in the University of Munich, in
the Kingdom of Bavaria, Empire of Germany.
In the Specification of Letters Patent granted to me for an Invention of
"Improvements in Preparing Coloring Matters suitable for Dyeing and Printing, and
in Materials Used in the Manufacture of the same," and dated Eighteenth March
1880, No. 1177, I have described a process for producing so called "artificial
indigo" by submitting ortho-nitro-phenyl-propiolic acid to the action of reducing or
deoxydising agents, such as glucose or similar bodies, in the presence of caustic or
carbonated alkalies, or of alkaline earths.
In the Specification of Letters Patent granted to me for an Invention of
"Improvements in Dyeing, Printing, and Marking Textile Fabrics and Materials,"
and dated the 30th April 1880, No. 1771, I have described the manner in which the
above mentioned process may be applied to dyeing, printing, and marking purposes
by producing artificial indigo within the fibre of textile fabrics and materials.
Now my foreign correspondent has communicated to me that artificial indigo
may be produced from ortho-nitro-phenyl-propiolic acid by replacing the reducing
or deoxydising agents named in the above recited Letters Patent, such as glucose,
milk, sugar, or similar saccharine substances, by the sulphides, sulphydrates, poly-
sulphides, sulpho-carbonates, and sulpho-carbonic ethers of the alkali metals, and
alkaline earth metals, and more especially by the alkaline ethyl-disulpho-carbonates
or xanthates.
The said sulphur compounds are capable of effecting the production of artificial
indigo from ortho-nitro-phenyl-propiolic acid in the cold, or at an ordinary
temperature; their reaction may however be perceptibly assisted by heat. The said
reagents may be employed in aqueous or alcoholic solution, but in the case of
xanthates being used, the desired deoxidation of ortho-nitro-phenyl-propiolic acid
chiefly proceeds after the evaporation of the solvent.
The following is an example of the manner in which this Invention may be
applied to the preparation of artificial indigo:-Ortho-nitro-phenyl-propiolic acid,
say, about ten parts by weight, is taken and neutralized with a solution of a caustic
or carbonated alkali, say, with a solution of about two parts by weight of pure
hydrate of sodium in about ten parts of water, and a solution of an alkaline
sulphydrate, say, about three parts by weight of sulphydrate of sodium dissolved
in about six parts of water, is then gradually added, and the reaction is allowed to
proceed at an ordinary or an elevated temperature, say, at from about 20 to 50
degrees centigrade; until the formation of a dark colored precipitate appears to be
finished, or until no appreciable amount of unchanged ortho-nitro-phenyl-propiolic
acid can be detected in the filtered liquor by means of the glucose test, as is well
understood by chemists. The said precipitate contains artificial indigo blue and
purple or red allied coloring matters, and also free sulphur; it may be collected on
à filter, washed with water and dried, and the sulphur if desired may then be
removed by treatment with bisulphide of carbon, or by any other convenient
method. The artificial indigo thus obtained may or may not afterwards be treated
with alcohol or other suitable solvents, in order to extract therefrom purple or red
coloring matters allied to indigo blue, and the said coloring matters may thus be
separated and obtained in the dry state after the evaporation of the solvent.

page_text: As another example, and which in practice has been found to produce a larger
proportion of indigo blue than the above described action of alkaline sulphydrates,
about ten parts by weight of ortho-nitro-phenyl-propiolic acid are mixed with
about ten parts by weight of water, and the pasty mixture thus obtained is
neutralized with about four parts by weight of carbonate of potash, or with the
equivalent amount of any other caustic or carbonated alkali. A freshly prepared
and concentrated solution of pentasulphide of sodium, such, for instance, as may
be prepared by, saturating or boiling solution, of caustic soda with sulphur, and
concentrating the solution thus obtained to about 14 specific gravity, is then
gradually added in the cold until no further action is observed to be produced by
a fresh addition of the said pentasulphide, and until the latter appears in strong
The dark colored mixture thus obtained is then treated with water in
order to remove the soluble products, and the insoluble residue, which chiefly
consists of artificial indigo-blue and sulphur, is afterwards filtered, dried, and treated
with bisulphide of carbon or any other suitable solvent in order to remove the
sulphur. The indigo-blue remaining after the said treatment may then be further
purified by washings with alcohol, or it may be submitted to any other known
process in use for the preparation of pure or refined indigo blue.
! excess.
In an analogous manner ortho-nitro-phenyl-propiolic acid may be submitted to
the deoxydising action of an alkaline sulphide, such as sulphide of sodium or
potassium, by preference in a highly concentrated solution or in a similar manner;
the trisulpho-carbonates of the alkaline metals may be employed in the above
described process.
+
As another example, a mixture of an alkaline salt of ortho-nitro-phenyl-propiolic
acid, say, about ten parts by weight of ortho-nitro-phenyl-propiolate of sodium
with an alkaline xanthate, say, about fifteen parts by weight of xanthate of sodium,
and with as much water as is required to form a paste is prepared; the said mixture
is then allowed to dry up spontaneously, or the evaporation of the solvent may be
assisted by a moderate heat, say, by a temperature of about forty to fifty degrees
centigrade. The mixture gradually turns blue, and the reaction is finished within
about 48 hours, or when the blue color no longer increases in intensity, and no
appreciable amount of unchanged ortho-nitro-phenyl-propiolic acid
can be
discovered in the mixture by the glucose test, as is well understood by chemists.
The dark blue product thus obtained contains, in addition to coloring matters,
soluble salts or compounds, which may be eliminated therefrom by repeated
washings with water, and the insoluble residue may or may not be further purified,
as above described, by treatment with suitable solvents, such as bisulphide. of
carbon, alcohol, or by any other convenient method.
An example of the manner in which this Invention may be applied to dyeing,
printing, and marking purposes, by producing artificial indigo within or upon the
fibre of textile fabrics and materials is as follows:-
For dyeing textile fabrics, yarn, or cloth, with artificial indigo, a cold aqueous
solution containing an alkaline salt of ortho-nitro-phenyl-propiolic acid, and an
alkaline xanthate in the proportion of about one part by weight of the said acid to
about from one and a half to two parts by weight of the xanthate is prepared, and
with the said solution the materials to be dyed are impregnated; for dark shades &
concentrated solution is to be employed, say, for instance, a solution containing
about ten parts by weight of ortho-nitro-phenyl-propiolate of sodium, about fifteen
parts by weight of xanthate of sodium, and about one hundred parts by weight of
water, and for light shades the solution is to be diluted accordingly. The goods
are then allowed to dry and to age at a moderate temperature, say, from about
20° to 50° centigrade for about 48 hours, or until the blue color becomes fully
developed. The textile fabrics and materials thus dyed may then be washed and
dried.
For printing or marking purposes an alkaline salt of ortho-nitro-phenyl-
propiolic acid is mixed with an amount of gum water, starch, paste, or any other
suitable thickening, proportionate to the depth or shade of color required. An alkaline

page_text: xanthate is then added in the cold state, and this whole is well mixed. The
printing color or marking ink thus prepared ought to be employed without much
delay, as upon standing it is liable to decompose.
The textile fabric or material may also be first prepared. or impregnated with an
alkaline xanthate, and then be printed or marked with an alkaline salt of ortho-
nitro-phenyl-propiolic acid, or the latter salt may be applied first, and then a
printing color or marking ink containing the alkaline xanthate may be used.
After printing or marking by any of the above described methods, the blue color
becomes developed within the fibre of the textile fabric or material by mere drying
and ageing at a moderate temperature, steaming or heating is not required; after
the artificial indigo is fully produced, the goods may be washed and dried.
In practice the following process has been found to produce good.results :-In
printing cotton or linen with artificial indigo blue, take one pound by weight of
dry ortho-nitro-phenyl-propiolic acid, three pounds of water, and one pound by
weight of borax finely powdered, mix well. The mixture first becomes fluid, and
at last turns stiff; then add three quarts of white starch thickening (wheat starch),
inix well and strain. In the standard thus produced, dissolve immediately
before printing one pound and a half of xanthate of soda, stir well, and ready for use.
For lighter shades reduce the above printing color with the following:-In one
gallon of white starch paste dissolve about one pound. by weight of xanthate of
soda. For the preparation of the above printing color, borax answers best as an
alkaline solvent of ortho-nitro-phenyl-propiolic acid; it may however be replaced
by acetate of soda (from about 1 to 1%, lbs) or by about 6 ounces of pearlash or
soda. The acid may likewise be neutralized by a caustic alkali, but any excess of
caustic potash or soda ought to be carefully avoided.
With the above printing color the goods may then be printed and dried as usual.
The indigo blue is best developed by allowing the printed goods to remain in a
dry atmosphere and at an ordinary temperature for about 48 hours. After the
blue is ready formed the pieces are first thoroughly washed, then boiled in water
for half an hour, cleaned in a soap bath at a temperature not above 40° centigrade,
then washed, dried, and finished.
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be practically carried
out, I would observe in conclusion that what I consider to be novel and
original; and therefore claim as the Invention secured to me by the hereinbefore
in part recited Letters Patent is,―
First. The preparation of artificial indigo by submitting ortho-nitro-phenyl-
propiolic acid to the reducing or deoxydising action of the sulphides, sulphydrates,
polysulphides, sulpho-carbonates, and, sulpho-carbonic ethers, of the alkali metals
and alkaline earth metals, and more especially of the alkaline ethyl-disulpho-
carbonates or xanthates, substantially as herein before described.
Second. The application of the within described process for the preparation of
artificical indigo to dyeing, printing, and marking textile fabrics and materials, by
submitting ortho-nitro-phenyl-propiolic acid in or upon the fibre of textile fabrics,
yarn, or cloth to the reducing or deoxydising action of the before mentioned
alkaline ethyl-disulpho-carbonates, or xanthates, substantially as hereinbefore
described.
In witness whereof, I, the said John Henry Johnson, have to this my
Specification set my hand and seal, this Twenty eighth day of July, One
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sight handed and night..