IMPROVEMENTS IN THE PRODUCTION OF ANILINE BLACK, FOR PRINTING AND OTHER PURPOSES, AND IN DYEING ANILINE BLACK
Year: 1875

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane,
in the County of Middlesex, Patent Agent, for the Invention of
"IMPROVEMENTS IN THE PRODUCTION OF ANILINE BLACK, FOR PRINTING AND
OTHER PURPOSES, AND IN DYEING ANILINE BLACK."-A communication
PROVISIONAL SPECIFICATION left by the said Alexander Melville
Clark at the Office of the Commissioners of Patents, with his
Petition, on the 1st May 1875.
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County
of Middlesex, Patent Agent, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE PRODUCTION OF ANILINE BLACK FOR
PRINTING AND OTHER PURPOSES, AND IN DYEING ANILINE BLACK," to be as
follows:-
This Invention relates to the production of aniline black by the con-
current reaction on aniline oil or on its salts of certain metallic salts.
and of certain chromates or bichromates.

page_text: -
The salts suitable for producing the black are those of the following
metals:
Iron, copper, manganese, cerium, aluminum, chromium,
nickel, cobalt, tungsten, vanadium, lead, and generally all metals sus-
ceptible of two degrees of oxidation capable of conversion from the one
to the other. Take iron, for example, the salts of the protoxide of this
metal pass into the state of salts of sesquioxide by oxidation, while the
salts of the sesquioxide are changed into salts of protoxide under
reductive influences.
The said reaction may be applied in two distinct ways so as, 1st., to
produce a black in the state of paste or powder suited for printing on
fabrics or paper, and for the manufacture of colors, varnishes, and inks
of all kinds; and 2ndly., to produce the black in the fibres of the textile
fabric itself.
I will first describe the production of a black pigment in the form of
paste or powder.
The following is an example of the method I adopt:-I take a solution
of a salt of iron for example, whose base is at the maximum degree of
oxidation, and add thereto aniline oil so long as a precipitate is thrown
down. I then add to the semi-fluid mass an acid solution of bichromate
of potash. A black precipitate is formed, which I wash either by
filtration or decantation, first in. pure water and then in an alkaline
solution for removing the greenish tinge.
The total quantity of oxide employed should be sufficient to neutralize
the potash of the bichromate, and the oxide of chromium resulting
from the reduction of the chromic acid. The reaction is promoted by
raising the temperature.
I will now describe the production of the black on textile fibres. I
may employ either of the three following methods :—
First. I print with the aid of a suitable thickening, such as starch or
gum tragacanth, a mixture of a salt of aniline, salt of either of the
metals before indicated, and a soluble bichromate or chromate. The
color is then developed in the drying room.
Second. I print with a mixture of salt of aniline formed with an
organic acid and a metallic chromate, which is readily decomposable, and
then steam.

page_text: Third. I print a mixture of salt of aniline and a salt of one of the
metals before indicated, and afterwards pass it through a weak neutral
or preferably acid solution of chromate or bichromate.
The proportion of aniline in the mixture may vary from 5 to 10 per
cent.
The best relative proportions of the aniline, the metallic salt, and
the chromate or bichromate are those of their chemical equivalents.
I apply these reactions not only to pure aniline which gives a black
color, but also to commercial anilines producing shades bordering on
black; to toluidine, which gives a brown color; to naphthylamine,
which gives a puce color; and also to the alkaloids derived from aniline
by substitution, such as ethylaniline, methylaniline, diphenylamine, and
others.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alexander Melville Clark in the Great Seal Patent
Office on the 1st November 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the First day of May, in the year of
our Lord One thousand eight hundred and seventy-five, in the thirty-
eighth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Alexander Melville Clark, Her special
licence, that I, the said Alexander Melville Clark, my executors,
administrators, and assigns, or such others as I, the said Alexander
Melville Clark, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Inven-
tion for "IMPROVEMENTS IN THE PRODUCTION OF ANILINE BLACK FOR PRINTING
OTHER PURPOSES, AND IN DYEING ANILINE BLACK," a communication
AND

page_text: to me from abroad by William Jules Samuel Grawitz, of Paris, France,
upon the condition (amongst others) that I, the said Alexander Mel-
ville Clark, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and scals, 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 I, the said Alexander Melville Clark, 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, that is to say :—
This Invention relates to the production of aniline black by the con-
current reaction on aniline or on its salts of certain metallic salts, and
of certain chromates or bichromates, the oxidizing action of the latter
being produced in a distinct operation, which may either follow or
precede the action of the metallic salts.
The salts suitable for producing the black are those of the following
metals: Iron, copper, manganese, cerium, aluminium, chromium, nickel,
cobalt, tungsten, vanadium, lead, and generally all metals susceptible of
two degrees of oxidation capable of conversion from the one to the
other. Take iron for example, the salts of the protoxide of this metal
pass into the state of salts of sesquioxide by oxidation, while the salts
of the sesquioxide are changed into salts of protoxide under reductive
influences.
The said reaction may be applied in two distinct ways so as, 1st, to
produce a black in the state of paste or powder suited for printing on
fabrics or paper, and for the manufacture of colors, varnishes, and inks
of all kinds; and 2ndly, to produce the black in the fibres of the textile
fabric itself.
I will first describe the production of a black pigment in the form of
paste or powder.
The following is an example of the method I adopt :-I take for
example, a solution of a persalt of iron, that is to say, a salt whose base
is at the maximum degree of oxidation, and add thereto aniline oil until
a precipitate ceases to be thrown down. I then add to the now semi-

page_text: fluid mass an acid solution of bichromate of potash. A black pre-
cipitate is formed, which I wash either by filtration or decantation, first
in pure water and then in an alkaline solution for removing the greenish
tinge.
The total quantity of oxide employed should be sufficient to neutralize
the potash of the bichromate, and the oxide of chromium resulting from
the reduction of the chromic acid. The reaction is promoted by raising
the temperature.
I will now describe the production of the black on textile fibres. I
may employ either of the three following methods :—
First. I print, with the aid of a suitable thickening, such as starch
or gum tragacanth, a mixture consisting of, 1st, a salt of aniline; 2nd,
a salt of either of the metals before mentioned; and 3rd, a soluble
bichromate or chromate. The color is then developed in the drying
room.
Second. I print with a mixture of an organic salt of aniline and a
metallic chromate, which is readily decomposable, and I then "steam."
Third. I print with a mixture of salt of aniline and a salt of one of
the metals before mentioned, and afterwards pass it through a weak
neutral, or preferably acid solution of a soluble chromate or bi-
chromate.
The proportion of aniline in the mixture may vary from 5 to 10 per
cent.
The best relative proportions of the aniline, the metallic salt, and the
chromate or bichromate, are those of their chemical equivalents.
I apply these reactions, not only to pure aniline which gives a black
color, but also to commercial anilines producing shades bordering on
black; to toluidine, which gives a brown color; to napthylamine, which
gives a puce color; and also to the alkaloids derived from aniline by
substitution, such as ethylaniline, methylaniline, diphenylaniline, and
others of similar composition.
Having described the nature of the Invention, and the manner of
performing the same, I declare that what I claim as the Invention to be
protected by the herein-before in part recited Letters Patent is, the pro-
duction of aniline black or shades bordering on black, either in the

page_text: state of paste or powder, or in the fibres of the textile fabric itself, by
the concurrent reaction on aniline oil, or on its salts or derivatives of
certain metallic salts herein specified, and a solution of soluble chromate
or bichromate, the oxydizing action of the latter being produced in a
distinct operation, which may either follow or precede the action on the
aniline of the metallic salts, all as hercin-before described.
In witness whereof, I, the said Alexander Melville Clark, have
hereunto set my hand and seal, this Thirtieth day of October, in
the year of our Lord One thousand eight hundred and seventy-
five.