IMPROVEMENTS IN THE MANUFACTURE OF DYE-PRODUCTS FROM INDIGO AND SULPHOCON- JUGATED DERIVATIVES OF ANILINE
Year: 1881

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, for an Invention of "IMPROVEMENTS
IN THE MANUFACTURE OF DYE-PRODUCTS FROM INDIGO AND SULPHOCON-
JUGATED DERIVATIVES OF ANILINE." A communication from abroad by
Charles Collin, of Paris, France.
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark
at the Office of the Commissioners of Patents on the 30th June 1881.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of
Middlesex, Patent Agent. "IMPROVEMENTS IN THE MANUFACTURE OF DYE-
PRODUCTS FROM INDIGO AND SULPHOCONJUGATED DERIVATIVES OF ANILINE." [A
communication from abroad by Charles Collin, of Paris, France.]
This Invention relates to the manufacture of dye products obtained by mixing
indigo or indigotine and so called sulpho-conjugated derivatives of aniline, and
more particularly what is known in France as noir-bleu (blue-black).
In a former Patent granted to me bearing date February 14th, 1878, No. 630, I
have described and claimed a process of reducing sulpho-conjugated derivatives of
aniline and more particularly blue-black, whereby they are rendered available for
dyeing in the same manner as natural indigo. It has been since found that by
mixing in the same vat a sulpho-conjugated aniline product with either indigo or
indigotine after reduction by either of the agents ordinarily used for reducing
indigo, constituting what may be termed a mixed vat, the most important results
are obtained both as regards economy and effect. The present Invention therefore
consists in the series of dye products obtained by the mixture of indigo or indigotine
with any of the sulpho-conjugated derivatives of aniline; for example, it is found
that a mixture of blue black (one of the sulpho-conjugated derivatives of aniline)
and indigo or indigotine, either in the form of sulphate of indigo or indigo carmine,

page_text: has a great practical value. The proportions and conditions of the mixture depend,
1st, upon the quantity of indigotine, or which is the same thing, upon the richness
in indigotine of the indigo employed; 2nd, upon the red and brown matters con-
tained in the indigo which are retained or eliminated either partially or entirely
according to the tint required. The mixture may be effected in either of the
following ways:-1st. By digesting the sulpho-conjugated derivative and indigo
in sulphuric acid as is now practised with indigo alone; or 2nd, by adding the
sulpho-conjugated derivative, and more particularly blue black to sulphate of indigo
already prepared; or 3rd, by digesting the sulpho-conjugated derivative and
indigotine in sulphuric acid, or by adding the sulpho-conjugated derivative and
more particularly blue-black to sulphate of indigotine already prepared.

page_text: 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
30th December 1881.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of
Middlesex, Patent Agent. "IMPROVEMENTS IN THE MANUFACTURE OF DYE-
PRODUCTS FROM INDIGO AND SULPHO-CONJUGATED DERIVATIVES OF ANILINE."
A communication from abroad by Charles Collin, of Paris, France.
This Invention relates to the manufacture of dye-products obtained by mixing
indigo or indigotine with so called sulpho-conjugated derivatives of aniline, and
more particularly with what is known in France as noir-bleu (blue-black).
In a former Patent granted to me bearing date February 14th, 1878, No. 630, I
have described and claimed a process of reducing sulpho-conjugated derivatives of
aniline and more particularly blue-black, whereby they are rendered available for
dyeing in the same manner as is natural indigo. It has been since found that by
mixing in the same vat a sulpho-conjugated aniline product with either indigo or
indigotine, and reducing by either of the agents ordinarily used for reducing indigo
(constituting what may be termed a mixed vat), the most important results are
obtained both as regards economy and effect. It will be evident that the indigo
or indigotine may be mixed with any blue obtained from an alkaloid derived from
coal tar and capable of being reduced, and I have here only instanced the sulpho-
conjugated derivatives of aniline, and preferably "noir-blue" by way of example.
The present Invention therefore consists in the series of dye-products obtained
by the mixture of indigo or indigotine with any blue capable of being reduced,
obtained from an alkaloid derivative of coal tar, and more especially from any one of
the sulpho-conjugated derivatives of aniline, and among others "noir-bleu." Taking
'noir-bleu" therefore merely by way of example (and reserving to myself the
right of applying an analogous treatment to any reducible blue obtained from an
alkaloid derived from coal tar), it has been found that the mixture of "noir-bleu.".
with indigo or indigotine, whether for dyeing in the vat by reduction by means of
any suitable reducing agent, or whether for dyeing by sulphates of indigo or indigo
carmine, is of considerable practical value. This new class of coloring matters,
which I term "mixed colors," acts from a tinctorial point of view in the same
way as indigo, but whilst equally effective it is very much more economical.
"3
Thus it has been found that (1) part of "noir-bleu" will give as deep a shade
as (3) parts of Bengal indigo, first quality, and by mixing 3 parts of indigo with
1 part of "noir-bleu a deeper color is obtained than if 6 parts of indigo were
employed. The same results are obtained with indigo carmine and sulphate of
indigo. If I add that there exists no means of separating a reducible blue obtained
from an alkaloid derived from coal tar (such as "noir-bleu" for example) from its
combination with indigotine, notwithstanding that the characters of the two
products are very different, it follows as an indisputable fact that this mixture or
combination gives rise to the formation, of a new product which I term a mixed
color. The proportions and conditions of the mixture depend, 1st, upon the
quantity of indigotine entering into the combination, or which is the same thing,
upon the richness in indigotine of the indigo employed; 2nd, upon the red and
brown matters contained in the indigo which are retained or eliminated either
wholly or in part according to the tint required.
I will now specify the best conditions of working that practice has suggested up
to the present time. The dye product resulting from the mixture of "noir-bleu"
(for example) and indigo or indigotine is obtained in the following manner :-
Either indigo or indigotine is mixed with "noir-bleu" and the whole ground up