IMPROVEMENTS IN DYEING THREADS, YARNS, AND FABRICS ANILINE BLACK
Year: 1874

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lanc,
in the County of Middlesex, Patent Agent, for the Invention of
" IMPROVEMENTS IN DYEING THREADS, YARNS, AND FABRICS ANILINE
BLACK." A communication from abroad by William Jules Samuel
Grawitz, of Paris, France.
Scaled the 6th April 1875, and dated the 21st October 1874.
•
PROVISIONAL SPECIFICATION left by the said Alexander Melville
Clark at the Office of the Commissioners of Patents, with his
Petition, on the 21st October 1874.
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 DYEING THREADS, YARNS, AND
FABRICS ANILINE BLACK," to be as follows:-
This Invention relates to dyeing all kinds of fibres, threads, yarns, or
fabrics black, or in shades appraoching thereto by means of aniline or
salts of the same.
•

page_text: The color is developed by the concomitant reaction on oil of aniline or
its salts of the following reagents, viz. :-1st, soluble chromate or bi-
chromate or soluble chlorate; 2ndly, salt of iron or copper whose basc is
at a maximum degree of oxidation.
The following is the method of applying this reaction for cotton and t
flax :-I pass the cotton through a bath containing in solution, with any
salt of aniline, a salt of iron or copper, as above. The cotton, after being
impregnated by the solution, is then drained, rinsed, and steeped in a
solution of soluble chlorate, or preferably chromate or bichromate. The
order of the operation may also be reversed. The intensity of the color 1
will be increased if the bath is acidified, but with acids which will not
affect the fibres, such a acetic acid for example.
In order to intensify the color on wool or silk it is preferable to employ
an energetic acid, such as sulphuric acid for example.
sing nonnations of the incendiants nea given me oxamples

page_text: The color will always be deeper when salts of copper are used instead
of salts of iron, while it varies from a brown to a blue or violet black,
according to the nature of the acid combined cither with the aniline or
with the iron or copper.
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 20th April 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 Twenty-first day of October, in the year of
our Lord One thousand cight hundred and seventy-four, 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 the said Alexander Melville Clark, 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
"IMPROVEMENTS IN DYEING THREads, Yarns, and FABRICS ANILINE BLACK,” 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
instrument 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.

page_text: is to be performed, to be particularly described and ascertained in and
by the following statement, that is to say :-
This Invention relates to dyeing aniline black or shades approaching
thereto by the concurrent reaction on aniline oil or on its salts of certain
metallic salts and a soluble chromate or bichromate.
The metals whose salts may be employed are the following:- Iron,
copper, manganese, cerium; aluminum, chromium, nickel, cobalt, tung-
sten, vanadium, load, 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 iron pass into the state of salts
of the sesquioxide by oxidation, while the salts of the sesquioxide of iron
are changed to salts of protoxide by reduction..
For dyeing textile matters black by means of aniline the following is
the method of operation, a salt of iron being employed for example:-I
form a bath, which I hereafter designate by the letter A, containing per
220 gallons of water 14 pints of hydrochloric acid at from 19 to 20 degrees
Beaumé, 7 pints of aniline oil, and 7 pints of liquid perchloride of iron at
45 degrees Beaumé.
I also form a second bath B containing water 220 gallons,' bichromate
of potash 17 lbs.
The textile matters (cotton for example) are mordanted in the first.
bath A, after which they are drained, and the liquid in excess carefully.
expressed and preserved. The cotton, after being mordanted in this
manner, is then digested in the second bath B for 5 or 6 hours. This
bath is sufficient to develop the color in two cwts. of cotton, for example.
The cotton is then removed from bath B, and washed in cold water, and
afterwards in lukewarm water, after which the same series of operations
is repeated, viz., 1st, mordanting in bath A; and, 2ndly, digesting in
bath B until a sufficient depth of colour is obtained. The completion of
the operation is indicated by the dyed matters presenting a brown tinge
or lustre after being thoroughly washed in cold and then in hot water on
leaving the bath of chromate.
The color, after a thorough washing in boiling water, may then be
brought to a bluish black by passing the cotton through a bath of boiling
soap water in the proportion of about 3 oz. per gallon. Carbonate of
soda may be used for imparting a violet hue..

page_text: Piece goods may be mordanted by dipping, and the development or
the color may be effected by passing the goods through a vat by means
of rollers on which the goods are wound, or other. similar apparatus may
be used. The development of the color is accelerated by increasing the
concentration of the liquors, and especially by increasing their degree of
acidity.
In dyeing cotton care should be taken not to employ anything which
would injure the fibre.
The chromate bath may be replaced by a bath of chlorate, but the
latter is more expensive, and the tints produced are inferior. I however
reserve the power to use the same.
Pure aniline alone will produce a perfect black of a bluish cast after
soaping. I however apply to Invention to anilines of commerce,
.toluidine, and to alkaloids derived from aniline by substitution. In this
manner I obtain shades verging on black, as well as puce color, by using
naphthylamine.
1 Cotton, flax, hemp, wool, silk, feathers, skins, hair, wood, and all
matters generally which are capable of absorbing moisture may be dyed
in the above manner.
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 hercin-before in part recited Letters Patent is, dyeing
aniline black, or shades approximate thereto, by the concurrent action
on anilinc oil or its salts of certain metallic salts herein specified, and of
a solution of a chromate, bichromate, or chlorate, as specified, the
oxidizing action of the latter being a distinct operation, that is to say,
this oxidizing action either succeeds or precedes the action of the
metallic salts on the aniline, all as herein-before described.
In witness whereof, I, the said Alexander Melville Clark, have
hereunto set my hand and seal, this Nineteenth day of April,
in the year of our Lord One thousand eight hundred and
seventy-five.