IMPROVEMENTS IN THE MANUFACTURE OF ANILINE DYES
Year: 1876

page_text: LETTERS PATENT to William Virgo Wilson, of 7, Cottage Grove, Bow, in the
County of Middlesex, Manufacturing Chemist, and Homington Caut, of 8,
Coborn Street, Bow, aforesaid, Analytical Chomist, for the Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF ANILINE DYES."
Sealed the 20th April 1877, and dated the 20th December 187
PROVISIONAL SPECIFICATION left by the said William Virgo Wilson and
Hemington Cant at the Office of the Commissioners of Patents on the 20th
December 1876.
WILLIAM VIRGO WILSON, of 7, Cottage Grove, Bow, in the County of Middlesex,
Manufacturing Chemist, and HEMINGTON CANT, of 8, Coborn Street, Bow, aforesaid,
Analytical Chemist. "IMPROVEMENTS IN THE MANUFACTURE OF ANILINE DYES."
This Invention has for its object the purification of rosaniline by means of benzole
or its homologues.
The rosaniline is first rendered basic by treating its crude salts with caustic soda,
lime, or other well known roagent of this class. The resulting product being crude
rosaline base we then digest with commercial benzole, preferring that of a low
boiling point. By this process the chrysaniline and chrysotoluidine, together with
the associated resinous and gummy matters are dissolved and may by filtration be
separated from the rosaniline, which after further washing in the same manner
remains in a high state of purity. The chrysaniline and chrysotoluidine may then be
recovered by the evaporation of the bonzole, and after purification by well known
means can be sold as phosphine, a dye of great commercial importance.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said William Virgo Wilson and Hemington Cant in the Great Seal Patent
Office on the 4th May 1877.
WILLIAM VIRGO WILSON, of 7, Cottage Grove, Bow, in the County of Middlesex,
Manufacturing Chemist, and HEMINGTON CANT, of 8, Cobon Street, Bow, aforesaid,
Analytical Chemist. 'IMPROVEMENTS IN THE MANUFACTURE OF ANILINE DYES,”
[Paving 2.1 ¦

page_text: In the manufacture of rosaniline or red aniline dye certain secondary products are
simultaneously obtained, among these occurring chrysaniline and chrysotoludine,
yellow dyes known in commerce as as phosphine and other resinous products.
The object of our Invention is the separation of these associated bodies from the
red dye, and we effect this by first treating the crude red melt with a caustic alkali
or alkaline earth, in practice however prefering caustic soda, and we thus obtain
the colouring matter in a basic form..
When the above process is complete the resulting bases must be washed and dried,
and then submitted to the action of commercial benzol, either in the cold or by
heat, without pressure, or preferably with pressure, when after a sufficient digestion
with this reagent, that is, when the foreign matters are to a great extent dissolved,
the insoluble rosaniline base, now in a high state of purity, is collected upon a filter,
and can be at once employed for the manufacture of magenta crystals or other well
known dyes by the usual processes.
Commercial benzol is always associated with its higher homologues, which also
have a solvent action, but for the purposes of this Invention we prefer that known
as ninety per cent. benzol.
The vessel in which the operation is conducted may be of iron or copper or other
suitable material, and so enclosed as to prevent the loss of any appreciable quantity
of the solvent.
Bye-products and residues resulting from the manufacture of aniline dyes may
also be similarly treated.
Having thus described the nature of our Invention, and the method of performing
the saine, we would have it understood that we claim, the use of benzol for the
purification of red aniline dye in the manner above described.
In witness whereof, we, the said William Virgo Wilson and Hemington
Cant, have hereunto set our hands and seals, this Fifth day of March, in
the year of our Lord One thousand eight hundred and seventy-seven.