AN IMPROVED PROCESS FOR DYEING AND PRINTING WITH CERTAIN DERIVATIVES OF ANILINE
Year: 1878

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, for the Invention of "AN IMPROVED
PROCESS FOR DYEING AND PRINTING WITH CERTAIN DERIVATIVES OF ANILINE."
A communication from abroad by Charles Collin and Henri Lenicque, both of
Paris, France.
ealed the 2nd July 1878, and dated the 14th February 1878.
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark at
the Office of the Commissioners of Patents on the 14th February 1878.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent. "AN IMPROVED PROCESS FOR DYEING AND PRINTING WITH CERTAIN
DERIVATIVES OF ANILINE." [A communication from abroad by Charles Collin and
Henri Lenicque, both of Paris, France.]
This Invention relates to dyeing and printing with certain so-called sulpho-
conjugated aniline products (which have hitherto only been used as soluble products,
dyeing the fibre directly), and consists in treating these sulpho-conjugated derivatives
of aniline after special preparation with a reducing agent, and re-oxidizing after the
coloring matter has been deposited on the fibre.
It has been found that by the reduction by means of nascent hydrogen or a metal
in a pulverulent condition, such as iron reduced by hydrogen, sublimed zinc, &c., of
certain sulpho-conjugated products derived from aniline, and more especially the
sulpho-conjugated compound known as blue black (noir bleu), which has been
specially prepared for the reducing action, a considerable economy may be realized
in dyeing animal or vegetable fibres.
The following is a description of the process:-I take a sulpho-conjugated deri-
vative of aniline, which is but little or not at all suited for dyeing, or which would
produce a color of but little body, and, after having saturated the alkali which it
contains, reduce it by means of nascent hydrogen or metals in a pulverulent form,
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page_text: The fibrous material is then immersed therein for a sufficient length of time, and
afterwards exposed to the air, and in a few moments the color changes, and at same
time becomes fixed on the fibre. The vat may now be replenished with a fresh
quantity of coloring matter (together with a suitable proportion of the acid and the
reducing agent) to replace the neutralized and reduced coloring matter that absorbed
by the fibre, after which the vat is again ready for uso.
The nascent hydrogen is produced in the vat in the presence of the coloring
matter by the re-action of an acid on a metal, such as, for example, that of sulphuric
or hydrochloric acid on zinc or iron; or any other known method of producing
hydrogen may be employed.
When metallic powders are employed they are worked up into a paste with the
neutralized coloring matter, and to prepare the vat it is simply necessary to dissolve
the paste in water, the rest of the operation being performed in the manner before
described.
The operation is performed for each kind of fibrous material at the ordinary tem-
peratures employed, viz., 100° C. for wool, 80° to 90° C. for silk, and either cold or at
about 60° for cotton.
The Invention therefore consists in the neutralization and the reduction, for the
purpose of dyeing and printing and the subsequent re-oxidation of the sulpho-
conjugated derivatives of aniline, which have never hitherto been employed in
dyeing except as soluble products, dyeing the fibre directly in conjunction with more
or less acid.
The above described process is also applicable to other similar coloring matters.

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
13th August 1878.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent.
"AN IMPROVED PROCESS FOR DYEING AND PRINTING WITH CERTAIN
DERIVATIVES OF ANILINE" A communication from abroad by Charles Collin and
Henri Lenicque, both of Paris, France.
This Invention relates to dyeing and printing with certain aniline products, dis-
tinguished as "sulpho-conjugated" derivatives of aniline, which have hitherto only
been used as soluble products, dyeing the fibre directly. This method of employing
them is disadvantageous, as the coloring matter is only partially utilised, the dye is
not a fast color, and the process of application presents certain difficulties.
It has been found that very much better and faster colors are obtained by
reducing these sulpho-conjugated derivatives of aniline [and more particularly that
made and sold in France under the name of "noir bleu" (blue black)] by means of
nascent hydrogen, and re-oxidising the reduced coloring matter after it has been
deposited on the fibre. The noir bleu above referred to is obtained by the re-action
of nitro-benzine or aniline at a high temperature in the presence of hydrochloric acid
and iron, as described in the Specification of a previous Patent granted to me, and
dated December 24th, 1867, No. 3657.
This Invention therefore consists in reducing by means of nascent hydrogen the
said sulpho-conjugated derivatives of aniline, and particularly the product called
noir bleu (after special preparation, as hereafter described), immersing in the solution
of reduced coloring matter so obtained the goods to be dyed, and then exposing the
same to the action of the air so as to re-oxidise the reduced coloring matter which
has been absorbed.
The special preparation above referred to consists in one of the following preli-
minary operations :-
1st. If in consequence of the process of manufacture adopted the said coloring
matter is acid, the quantity of acid present may be ascertained and reduced to the
exact proportion necessary to produce with the corresponding proportion of metal
(subsequently added, as hereafter described) the quantity of hydrogen desired.
2nd. Instead of reducing the quantity of acid present to a certain proportion, the
acid may be entirely removed by washing, in which case the proper proportions of
acid and metal must be afterwards added to the neutral coloring matter in order to
produce the quantity of hydrogen necessary, as hereafter described, for the case in
which the material is alkaline.
3rd. If the coloring matter is alkaline it is neutralised by the addition of sufficient
acid to saturate the alkali it contains, and the proper proportions of acid and metal
must be afterwards added to the neutral coloring matter in order to produce the
quantity of hydrogen necessary, as herein-after described.
In carrying out this Invention I take a sulpho-conjugated derivative of aniline
(which may be acid, neutral or alkaline), say, for example, the product above desig-
nated as noir bleu, and suppose it to be alkaline I first saturate the alkali which it
contains as above directed, and I then place it in a vat containing boiling water
together with substances capable of producing nascent hydrogen, such as sulphuric,
hdrochloric, or other similar acid, and a metal, such as zinc or iron, in small pieces,
or better still in powder (or any other suitable method of producing nascent hydrogen
may be adopted).
The hydrogen generated in the presence of the coloring matter itself reduces the
latter, which changes from blue to a greenish yellow; I thus obtain a solution of
reduced coloring matter, which I employ as follows:-
I would first observe that the vat, before the acid and metal are. added, as above
described, may be either neutral or acid, except when the sulpho-conjugate was.

page_text: alkaline at first, and afterwards neutralised, in which case a better result is
obtained if the vat gives an acid re-action before the further addition of acid and
and metal is made.
The reduction of the coloring matter having been effected, as above described, the
liquid is raised to the ordinary temperature employed for each kind of material [viz.,
100° C. (212° F.) for wool, 80° C. (176° F.) to 90° C. (193° F.) for silk and cotton], care
being taken to cover the vat with a lid to prevent the access of air. The cover is
then removed, the goods to be dyed are immersed in the liquid, and the cover
replaced. When it is judged by experience that the goods have been kept in the
vat a sufficient time to absorb enough of the coloring matter to give the desired
tint, the goods are removed from the vat and exposed to the air, by which the
coloring matter is rapidly re-oxidised and fixed on the fibre, and at the same time
caused to return to its original blue color. The vat, which is not entirely exhausted,
may now be replenished with a fresh quantity of coloring matter, metal, and acid in
the proper proportions to effect the reduction of the fresh coloring matter, after which
the vat is again ready for use.
I will now give by way of example the proportions I prefer to employ.
Water
Woollen goods
Coloring matter
Zinc in powder-
Sulphuric acid
-
-
1 cubic metre (220 gallons).
30 kilos. to 40 kilos. (462,960 to 617,280 grains).
1 kilo. (15,432 grains).
-
1 kilo. (15,432 grains).
50 grammes (771 grains).
When the water used contains lime, sulphuric acid is first added in such quantity
that the water will just redden litmus paper.
The dyeing process may be slow or rapid; it depends,―
(1st) Upon the strength of the vat, the dyeing being more rapid in a vat con-
taining much coloring matter than in a weak vat.
(2.) Upon the depth of tint required.
(3.) On the temperature of the vat, which acts more energetically at 100° C. than
at 80° or 90° C.
(4.) On the nature of the fibre; a fine wool requires a longer immersion than a
common wool.
(5.) On the more or less complete reduction of the coloring matter, and conse-
quently on the quantity of hydrogen produced, a vat in which the coloring matter
is reduced with an excess of hydrogen dyeing more rapidly than one in which the
hydrogen is produced in insufficient or just sufficient quantity.
I will now describe the application of the Invention to printing fabrics, say, of
wool or silk.
It will be understood that the proportions indicated may be varied according to
circumstances.
First. I make a paste composed, for example, of,-
Coloring matter (neutral or neutralized) 1 kilogramme (15,432 grains).
Metal, such as zinc
Gum
-
2 kilogrammes (30,864 grains).
-
3 kilogrammes (46,296 grains).
In order to ensure perfect regularity in the depth of color the colouring matter
and the zinc should be intimately ground together.
Secondly. I make the following mixture:-
Sulphuric acid at 66° Beaumé
Gum
-
200 grammes (3,086 grains).
3 kilogrammes (46,296 grains).
The gum should be in the form of a syrup marking 35° B., and it may be gum
tragacanth, gum senegal, or dextrine. When about to print I mix together these
two compositions, and I print therewith in the ordinary way, steam the goods, and
allow the color to dry before washing.
Brighter colors may be obtained by grinding intimately together 1 kilogramme
(15,432 grains) of coloring matter and 2 kilogrammes (30,864 grains) of zinc, and
throwing this mixture into 10 litres (2 gallons 2 pints) of boiling water, to which is
afterwards added 200 grammes (3,086 grains) of sulphuric acid, care being taken to

page_text: stir the liquid whilst adding the acid gradually. The liquid is then placed on a
filter, and the clear liquid is run into 6 litres (10 pints) of gum syrup marking
35° B. I print with this syrupy mixture, steam, and allow the color to dry before
washing.
Having described the nature of the said 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 reduction by means of nascent
hydrogen of the sulpho-conjugated derivatives of aniline (and particularly that known
as noir bleu), as and for the purpose herein specified, and dyeing or printing with
the reduced coloring matter, and afterwards re-oxidising the same by exposure to
the air.
In witness whereof, I, the said Alexander Melville Clark, have hereunto set
my hand and seal, this Thirteenth day of August, in the year of our Lord One
thousand eight hundred and seventy-eight.