IMPROVEMENTS IN DYEING TEXTILE FIBRES BLACK OR GREY COLORS WITH ANILINE
Year: 1877

page_text: LETTERS PATENT to Thomas Holliday, of the Firm of Read, Holliday, and
Sons, of Huddersfield, in the County of York, Manufacturing Chemists, for the
Invention of "IMPROVEMENTS IN DYEING TEXTILE FIBRES BLACK OR GREY
COLORS WITH ANILINE." A communication from abroad by William Jules
Samuel Grawitz, of 1, Boulevard Henry IV., Paris, in the Republic of France.
Sealed the 18th December 1877, and dated the 9th October 1877.
PROVISIONAL SPECIFICATION left by the said Thomas Holliday at the Office
of the Commissioners of Patents on the 9th October 1877.
THOMAS HOLLIDAY, of the Firm of Read, Holliday, and Sons, of Huddersfield, in
the County of York, Manufacturing Chemists. "IMPROVEMENTS IN DYEING TEXTILE
FIBRES BLACK OR GREY COLORS WITH ANILINE." A communication from abroad
by William Jules Samuel Grawitz, of 1, Boulevard Henry IV., Paris, in the Republic
of France.
The Invention consists in dyeing textile fibres black and grey colors of different
shades with aniline without the necessity of ageing, and in one single bath, by the
following reactions
Progressive transformation is obtained on textile fibres of aniline in an acid solu-
tion into the green products known by the generic name emeraldine by the oxidizing
action of the metallic salts and acids which are known to produce them, and the
changing of these green products in the same bath into black or grey by the action
of chromic acid.
When, for example, say about ten pounds of yarn or cotton are required to be
dyed, these matters to be dyed are placed in a bath containing one pound of aniline
in about twenty gallons of water, and the other reactives indicated above are added
in about chemical equivalent proportions, the presence of the textile fibres prevents
the formation of a precipitate in the liquor by absorbing the color, and they become
green, and deeper in color until they are black, in proportion to the quantity of
chromic acid that is reduced.

page_text: The rapidity of the reaction and the shade and quality of the color obtained
varies according to the concentration and temperature of the bath, the quantity of
chromic acid, the nature and quantity of aniline, acids, and metals employed.
Grey shades are obtained by diminishing the quantity of the chemicals employed,
one-fifth the quantity in the example giving a grey.
The metals employed in the bath in the state of salts or acids, notably the chrome,
are fixed wholly or partially on the fibre with the coloring matter.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas Holliday in the Great Seal Patent Office on the 28th March
1878.
THOMAS HOLLIDAY, of the Firm of Read, Holliday, and Sons, of Huddersfield, in
the County of York, Manufacturing Chemists. "IMPROVEMENTS IN DYEING TEXTILE
FIBRES BLACK OR GREY COLORS WITH ANILINE." (A communication from abroad
by William Jules Samuel Grawitz, of 1, Boulevard Henry IV., Paris, in the Republic
of France.)
The Invention consists in dyeing textile fibres black and grey colors of different
shades with aniline without the necessity of ageing, and in one single bath by the
following reactions :—
Progressive transformation on textile fibres of aniline in an acid solution into the
green products known by the generic name emeraldine is obtained by the oxidizing
action of the metallic salts and acids which are known to produce them, and the
changing of these green products in the same bath into black or grey is further
obtained by the action of chromic acid.
When, for example, say about ten pounds of yarn or cotton are required to be
dyed, these matters to be dyed are placed in a bath containing one pound of aniline
in about twenty gallons of water, and the other reactives indicated above are added
in about chemical equivalent proportions. The presence of the textile fibres prevents
the formation of a precipitate in the liquor by absorbing the color, and the result is
that such textile fibres first become green, and then gradually deeper in color until
they become black in depth in proportion to the quantity of chromic acid that is
reduced.
It will generally be found advantageous to apply heat towards the end of the
operation, particularly when the only metal employed is chromium. The tempera-
ture of the bath may be raised to near the boiling point. The completion of the opera-
tion will be readily ascertained by the color obtained resisting the action of sulphurous
acid.
The rapidity of the reaction and the shade and quality of the color obtained varies
according to the concentration and temperature of the bath, the quantity of chromic
acid, the nature and quantity of aniline, acids, and metals employed.
Grey shades are obtained by diminishing the quantity of the chemicals employed,
one-fifth the quantity in the example giving a grey color.
The metals employed in the bath in the state of salts or acids, notably the chrome,
are fixed wholly or partially on the fibre with the coloring matter.

page_text: Having thus described the Invention as communicated to me, I would have it
understood that what I claim is, the improvements in dyeing textile fibres black or
grey colors with aniline in a single bath, substantially as described.
In witness whereof, I, the said Thomas Holliday, have hereunto set my hand
and seal, this Twenty-sixth day of March, in the year of our Lord One
thousand eight hundred and seventy-eight.
Witness,
ALFRED GEORGE BROOKES,
37, Southampton Buildings,
Chancery Lane,
London.
THOMAS HOLLIDAY. (LS.)