IMPROVEMENTS IN THE MANU- FACTURE OF COLOURING MATTERS
Year: 1882

page_text: LETTERS PATENT to Ivan Levinstein, of the City of Manchester, in the County
of Lancaster, Chemist, for an Invention of "IMPROVEMENTS IN THE MANU-
FACTURE OF COLOURING MATTERS
"
PROVISIONAL SPECIFICATION left by the said Ivan Levinstein at the
Office of the Commissioners of Patents on the 30th November 1882.
IVAN LEVINSTEIN, of the City of Manchester, in the County of Lancaster,
Chemist, "IMPROVEMENTS IN THE MANUFACTURE OF COLOURING MATTERS."
:
My invention has for its object the production of yellow colouring matters, or
mixtures of the same, and consists in obtaining these products, by the action of
nitric acid upon the mono- and di-sulpho acid of Nitroso alpha naphtol or upon
mixtures of the same, and in the means and process employed therein; and
according to my present experience I prefer to dissolve 10 parts by weight of
Alpha Naphtol in 40 parts by weight of ordinary commercial rectified sulphuric
acid marking about 170 on Twaddels hydrometer, at a. temperature of about
100 degrees centigrade; as soon as the whole of the Naphtol is dissolved I increase
the temperature to about 130 degrees centigrade and keep it at that heat, for about
one hour, when the Alpha Naphtol will be converted principally into a disulpho
acid of Alpha Naphtol. I then treat this alpha naphtol sulpho acid (after previously
diluting it with about 30 parts of water) with 4-6 parts of Nitrite of Soda, or as
much as will be necessary to convert the same into a Nitroso alpha naphtol sulpho
acid, taking great care to keep the temperature as low as possible, by ice or other
means and not allowing it to rise above 10 degrees centigrade.
As soon as the whole of the Nitrite of soda is added; I prepare 24 parts of
Nitric acid of 1.456 specific gravity and dilute this with about 24 parts of water,
and add this diluted acid to the Nitroso alpha naphtol sulpho acid and let the
whole mixture stand for 2 to 3 days, when a large quantity of crystals will be
formed which I then remove by filtration or by any other means. These
crystals which have acid properties and dye a bright yellow may be either
used in this state or they may be converted into salts in a manner well known to
Chemists.
Instead of allowing the above mixture to stand for 2 to 3 days it may be
heated at once to boiling, when crystals will be thrown off but the result in not
so satisfactory.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Ivan Levinstein in the Great Seal Patent Office on the 26th May
1883.
IVAN LEVINSTEIN of the City of Manchester in the County of Lancaster,
Chemist, IMPROVEMENTS IN THE MANUFACTURE OF COLOURING MATTERS,"
"
My invention has for its object the production of yellow colouring matters or
mixtures of the same, and consists in obtaining these products by the action of
nitric acid upon the mono- and di-sulpho acid of Nitroso alpha Naphtol or upon
mixtures of the same, and in the means and process employed therein, and according
to my present experience I prefer to dissolve 10 parts by weight of Alpha Naphtol
in 40 parts by weight of ordinary commercial rectified sulphuric acid marking
about 170 degrees on Twaddells bydrometer, at a temperature of about 100 degrees
centigrade; as soon as the whole of the Naphtol is dissolved I increase the
temperature to about 130 degrees centigrade and keep it at that heat for about one
hour, when the Alpha Naphtol will be converted principally into a disulpho acid
of Alpha Naphtol-I then dilute this Alpha Naphtol sulpho acid by the addition of
30 parts by weight of water, and afterwards treat it with 46 parts by weight of
Nitrite of Soda or as much as will be necessary to convert the same into a Nitroso
alpha Naphtol sulpho acid, taking great care to keep the temperature as low as
possible, by ice or other known means of abstracting heat, so as not to allow it to
rise above 10 degrees centigrade.
As soon as the whole of the Nitrite of soda is added I prepare 24 parts by weight
of Nitric acid of 1456 specific gravity and dilute this with about 24 parts by
weight of water, and add this diluted acid to the Nitroso alpho naphtol sulpho
acid and let the whole mixture stand for 2 to 3 days at the ordinary température
when a large quantity of crystals will be formed, which I then remove by filtration
or by any other convenient means. These crystals which have acid properties and
dye a bright yellow are or may be either used in this state or they are or may be
converted into salts in a manner well known to Chemists.
Instead of allowing the said mixture to stand for to to 3 days, at the ordinary
temperature as above stated the temperature may be at once increased eventually
even to boiling when crystals will be thrown off but I prefer the crystallization
to take place by allowing the mixture to stand a few days at the ordinary
temperature.
I have now particularly described the nature of my said invention and the modes
of carrying the same into effect and claim as my invention.
Firstly. Yellow colouring matters or mixtures of the same obtained by the action
of nitric acid on the mono or di-sulpho acid of alpha nitroso naphtol or other
mixtures of these two acids.
Secondly. The production of and process for obtaining yellow colouring matters
or mixtures of the same by the action of nitric acid on the mono or di-sulpho acid
of alpha nitroso naphtol or on mixtures of these two acids, substantially as herein-
before described.
In Witness whereof I the said Ivan Levinstein have hereunto set my hand
and seal this twenty fifth day of May in the year of our Lord one
thousand eight hundred and eighty three.