IMPROVEMENTS IN THE TREATMENT OF INDIGO FOR USE IN, DYEING AND. PRINTING
Year: 1883

page_text: 1
LETTERS PATENT to William Brookes of 59 Chancery Lane, London, in the
County of Middlesex, Patent Agent for an Invention of "IMPROVEMENTS IN
THE TREATMENT OF INDIGO FOR USE IN, DYEING AND. PRINTING" communi-
cated to him from abroad by Thomas Holliday of the firm of Read Holliday
and Sons of Huddersfield in, the County of York, but at present residing
at Houlme near Malaunay Seine Inférieure, in the Republic of France
Manufacturing Chemist.
'
PROVISIONAL SPECIFICATION left by the said William Brookes at the
Office of the Commissioners of Patents on the 18th May 1883.
1.A
.
I
WILLIAM BROOKES of 59 Chancery Lane, London, in the County of Middlesex,
Patent Agent;
"IMPROVEMENTS IN THE TREATMENT OF INDIGO FOR USE IN
DYEING AND PRINTING." (communicated to me from abroad by Thomas Holliday
of the firm of Read Holliday and Sons of Huddersfield in the County of York but
at present residing at Houlme near Malaunay, Seine Inférieure, in the Republic of
France, Manufacturing Chemist.).
In carrying out my improvements I precipitaté artificial Alizarine, Alpha ör
Beta Napthols, Resorcine or other bodies formed by treating sulpho-compounds
with caustic potash or caustic soda for the purpose of introducing the hydros-cyl
from the melt produced by such treating by the use of sulphurous acid which I add
to the hot or cold solution of the melt until it shews an acid reaction. I then filter
the resulting imagma and I then further saturate the filtrate with sulphurous acid
if such filtrate be not thoroughly or sufficiently saturated before such filtration-
and I employ the saturated filtrate, in dissolving, and dyeing with indigo, by
converting the same into impure Hydrosulphites with iron or zine and I mix the
converted matters with Indigo adding sufficient lime to hold the Indigo white
produced in solution and I use the same converted impure hydrosulphite already,
described in dyeing with Indigo by adding it to an Indigo vat thereby keeping the
Indigo deoxidised during the process of dyeing.
This process has the advantages of not only utilizing the alkali employed in the
manufacture of the melt but also the sulphurous acid formed in the production of
the melt. I am consequently enabled to economise or dispense, with the use of the
bisulphite of soda usually employed for dissolving and dyeing with Indigo,' in' a
pure or comparatively pure state.
...

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Brookes in the Great Seal Patent Office on the 15th November
1883.
WILLIAM BROOKES of 59, Chancery Lane, London in the County of Middlesex
Patent Agent
"IMPROVEMENTS IN THE TREATMENT OF INDIGO FOR USE IN
DYEING AND PRINTING ." (communicated to me from Abroad by Thomas Holliday
of the firm of Read Holliday and Sons of Huddersfield in the County of York but
at present residing at Houlme near Malaunay Seine Inférieure in the Republic of
France Manufacturing Chemist
In carrying out my improvements I precipitate artificial Alizarine Alpha-, or
Beta, Napthols, Resorcine, or other bodies, formed by heating sulpho-compounds
with caustic potash, or caustic soda, for the purpose of introducing the hydroxyl
from the melt produced by such heating by the use of sulphurous acid which I add
to the hot, or cold, solution of the melt until it shows an acid reaction I then filter
the resulting magma and I then further saturate the filtrate with sulphurous acid,
if such filtrate be not thoroughly or sufficiently saturated before such filtration
and I employ the saturated filtrate in dissolving and dyeing with indigo by
converting the same into impure hydrosulphites with iron, or zinc, and I mix the
converted matters with Indigo adding sufficient lime to hold the Indigo white
produced in solution and I use the same converted impure hydrosulphite already
described in dyeing with Indigo by adding it to an Indigo vat thereby keeping the
Indigo deoxidized during the process of dyeing
As a further example of means of carrying this invention into practical effect I
give the following detailed instance
Taking (say) the melt produced by fusing Sulpho napthaline with caustic soda
I dissolve the same in hot water to such an extent that the solution will indicate
(say) 10° Besumé and I neutralize the alkali by passing through the melt sulphurous
gas until all the napthol therein is precipitated, or I dissolve the melt in as little
water as is practicable and I add thereto a super saturated solution filtered from a
previous treatment of melt, until the napthol is precipitated by the sulphurous acid
in excess.
I then filter the resulting magma to separate the napthol and if the filtrate has
not already as much sulphurous acid in it as it is capable of taking up I pass
still more sulphurous gas through it-the fact of the filtrate having already
sulphurous acid in quantity, as great as it will take up may be known by its
strong smell.
The super-saturated product may then be employed for reducing indigo by
adding to it about six per centum (6%) of zinc in a state of powder, or as much
zinc as will cause the strong smell of sulphurous acid to disappear and the mixture
may then be added to ground indigo in its dry state, or in water, in such quantity
that the blue of the indigo disappears and by having lime present the white of
indigo so produced will pass into solution. This solution can then be added to
more water and employed for dyeing or printing purposes, or the indigo in a dye
bath can be reduced or deoxydized by adding to it the supersaturated product
mixed with zinc and, further adding enough lime to keep the indigo in
solution, A condition which will be apparent to any one accustomed to dyeing
with Indigo
This process has the advantages of not only utilizing the alkali employed in the
manufacture of the melt, but also the sulphurous acid formed in the production of
the melt. I am consequently enabled to economise, or dispense, with the use of the

page_text: bisulphite of soda usually employed for dissolving and dyeing with indigo in a
pure, or comparatively pure, state
Having thus described my Invention and means I adopt in carrying the same
into practical effect I would have it understood that what I claim is the
"Improvements in the treatment of indigo for use in dyeing and printing
whereby I attain the utilization of the alkali and sulphurous acid present in the
melt produced by heating sulpho compounds with caustic soda or caustic potash
substantially as herein described.
In witness whereof I the said William Brookes have hereunto set my hand
and seal this Twelfth day of November in the year of our Lord One thousand eight
hundred and eighty three
Witness: ALFRED GEORGE BROOKES.
59 Chancery Lane London.
Patent Agent.
WILLIAM BROOKES (L.S.)