IMPROVED PROCESSES FOR THE MANUFACTURE OF ARTIFICIAL PURPURINE AND OTHER COLORING MATTERS, TOGETHER WITH THE APPLICATIONS OF SUCH PRODUCTS
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
"IMPROVED PROCESSES FOR THE MANUFACTURE OF ARTIFICIAL PURPURINE
AND OTHER COLORING MATTERS, TOGETHER WITH THE APPLICATIONS OF SUCH
PRODUCTS." -A communication from abroad by William Jules Samuel
Grawitz, of Paris, France.
Sealed the 5th May 1876, and dated the 29th November 1875.
PROVISIONAL SPECIFICATION left by the said Alexander Melville
Clark at the Office of the Commissioners of Patents, with his
Petition, on the 29th November 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 "IMPROVED PROCESSES FOR THE MANUFACTURE OF
ARTIFICIAL PURPURINE AND OTHER COLORING MATTERS, TOGETHER
APPLICATIONS OF SUCH PRODUCTs," to be as follows:-
.
WITH THE
This Invention relates to the manufacture of artificial purpurine, and
to its applications for dyeing and printing purposes, and also to the

page_text: production and application of other tinctorial products obtained in the
processes followed in making purpurine.
I produce artificial purpurine by either of the two following
methods :-
1st. By the transformation of the nitro-derivatives of artificial or
natural alizarine by the action of sulphuric acid concentrated by the aid
of heat (212° to 572° Fahr.).
2ndly. By the transformation of the oxychloric derivatives of
alizarine under the same conditions.
To form the nitro-derivatives of alizarine the latter may, for example,
be acted on by nitric acid or its salts in presence of concentrated sul-
phuric acid. A product is thus obtained which by the elevation of the
temperature disengages, under the influence of the sulphuric acid,
oxygenated compounds of nitrogen, and becomes transformed into
artificial purpurine, which is separated by the addition of water.
The second method is similar, chloric or perchloric acids or their salts
being substituted for the nitric acid or its salts.
The intermediate compounds formed in these reactions, viz., in the
first method, nitro-alizarine and nitro-oxyalizarine, and in the second
method chloroxyalizarine, are beautiful coloring matters, and constitute
novel tinctorial products suitable for use both in dyeing and printing.
These are obtained by not allowing the temperature to rise higher than
212° Fahr., and precipitating by water. These products are sparingly
soluble in cold water, and soluble in boiling water.

page_text: our Lord One thousand eight hundred and seventy-five, in the thirty-
ninth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Alexander Melville Clark, Her special
license that I, the said Alexander Melville Olark, my executors, admini-
strators, 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 Invention for
"IMPROVED PROCESSES FOR THE MANUFACTURE OF ARTIFICIAL PURPURINE AND
OTHER COLORING MATTERS, TOGETHER WITH THE APPLICATIONS OF SUCH PRODUCTS,'
a communication to me from abroad by William Jules Samuel Grawitz,
of Paris, France, upon the condition (amongst others) that I, the said
Alexander Melville Clark, my executors or administrators, by an instru-
ment in writing under my, or their, or one of their hands and seals,
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 manufacture of artificial purpurine, and
to its application for dyeing and printing purposes, and also to the pro-
duction and application of other tinctorial products obtained in the
processes followed in making purpurine.
The following are the products obtained :-
1st. Oxyalizarine or artificial purpurine formed by the transformation,
under the action of concentrated sulphuric acid and heat, of the nitro
derivatives or oxychloric derivatives of alizarine.
2nd. Nitro-alizarines, including,—
Mononitro-alizarine,
Binitro-alizarine,
M
I
10

page_text: 4th. Chloroxyalizarines.
The folowing is the process of preparing the oxyalizarine:-Alizarine,
either natural or artificial, is first dissolved in concentrated sulphuric
acid, either hot or cold. If heat be used the alizarine is allowed to cool
after being completely dissolved, so as to ensure regularity in the subse-
quent operations. Nitric acid is then added to the solution (the acid
being either free or in the form of a salt) in the proportion required by
the chemical equivalents, that is, about 26 per cent. in weight of the dry
alizarine treated. The temperature of the liquor is then gradually raised,
and on testing a drop of the liquor from time to time, by dissolving it in
potash, if the color resemble that of a red currant, without any tinge of
violet, the operation is complete, but if not a slight excess of nitric
acid is added.
The nitric acid or the nitrates may also be mixed with concentrated
sulphuric acid before being added to the sulphuric acid solution of
alizarine. When the operation is terminated the mass is run out in a
thin stream into a considerable quantity of water. The oxyalizarine
precipitates in flakes, and is then filtered and washed until the acids are
completely eliminated, and afterwards dried, if desired. The oxyali-
zarine, whether in paste or powder, may be employed generally in dyeing
and printing fabrics.
Chloric or perchloric acids or their salts may also be used to similarly
transform alizarine into oxyalizarine.
Preparation of Nitro-alizarines and Nitroxyalizarines.-If to a sul-
phuric acid solution of one equivalent of alizarine kept in a cold state
to prevent the formation of oxyderivatives be added one, two, or three
equivalents of nitric acid, either free or in the form of a salt, one, two,
or three equivalents of hyponitric acid are substituted for the same
number of equivalents of hydrogen, a sulphuric acid solution being
obtained containing three distinct compounds, viz.―
Mononitro-alizarine,

page_text: 1st. The manufacture of the following substances :-
1. Oxyalizarine.
2. Nitroalizarines.
3. Nitroxyalizarines.
4. Chloroxyalizarines.
2nd. The processes of preparing the above substances herein described.
3rd. The application of these various derivatives of alizarine and
oxyalizarine generally to dyeing and printing fabrics, these nitro-
derivatives and oxychloric derivatives being acids forming salts, with the
several bases of which I also claim the preparation and application for
the purposes mentioned.
In witness whereof, I, the said Alexander Melville Clark, have
hereunto set my hand and seal, this Twenty-seventh day of May,
in the year of our Lord One thousand eight hundred and seventy-
six.