A NEW OR IMPROVED PROCESS FOR THE MANUFACTURE OF RED AND YELLOW COLOURING SUBSTANCES
Year: 1882

page_text: LETTERS PATENT to Jasper Wetter, of New Wandsworth, Surrey for an
invention of A NEW OR IMPROVED PROCESS FOR THE MANUFACTURE OF RED
AND YELLOW COLOURING SUBSTANCES a communication from abroad by Otto
Bredt and Company, of Unter-Barmen, Germany.
PROVISIONAL SPECIFICATION left by the said Jasper Wetter at the Office
of the Commissioners of Patents on the 12th April 1882.
JASPER WETTER, of New Wandsworth, Surrey, A NEW OR IMPROVED PROCESS
FOR THE MANUFACTURE OF RED AND YELLOW COLOURING SUBSTANCES, a com-
munication from abroad by Otto Bredt and Company, of Unter-Barmen, Germany,
For producing red colouring matter a naphtylamine mixed with five times its
quantity of concentrated sulphuric acid is heated to a temperature of 120 degrees
Centigrade until the solution solidifies and becomes a stiff, greyish-white substance,
after which the excess of sulphuric acid is washed away with water.
This sulphonic acid, which has previously been diazotized by the calculated
quantity of sodic-nitrite and hydro-chloric acid, is caused to flow into a solution of
naphty lamine-sulphonic acid, which is kept strongly alkaline until the end of the
re-action the proportion of the mixture being: one molecule of the sulphonic acid to
two molecules of naphtylamine-sulphonic acid, and to this mixture is added the
quantity of sodic nitrite calculated for two molecules of naphtylamine-sulphonic
acid. Subsequently concentrated hydro-chloric acid is added, while continually
stirring, sufficient to liberate the nitrous acid and give to the whole liquid a
strongly acid re-action. The hexachloride compound thus formed is then united
with a solution of one molecule of B-naphtol in soda-lye, and the solution
carefully kept alkaline until the re-action is completed.
The product, which at the end of the process has the consistence of a broth, is
neutralized by hydro-chloric acid and heated to the boiling point-The colouring
matter is precipitated by common salt and purified by repeated solution and
precipitation. Similar colouring substances are produced by the action of one
molecule of diazobenzol-sulphonic acid on two molecules of naphtylamino-sulphonic
acid. By employing, instead of B-Naphtol, a Naphtol or its sulphonic acids, or
resorcin, or generally phenols, the colouring matters obtain tints ranging from
yellow to intense red.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Jasper Wetter in the Great Seal Patent Office on the 9th October
1882.
JASPER WETTER, of New Wandsworth, Surrey, A NEW OR IMPROVED PROCESS
FOR THE MANUFACTURE OF RED AND YELLOW COLOURING SUBSTANCES, a com-
munication from abroad by Otto Bredt and Company, of Unter-Barmen, Germany,
For producing red colouring matter a-naphthylamine mixed with five times its
quantity of concentrated sulphuric acid is heated to a temperature of 120 degrees
Centigrade until the solution solidifies and becomes a stiff greyish-white substance,
after which the excess of sulphuric acid is washed away with water. This
sulphonic acid, which has previously been diazotized by the calculated quantity of
sodic nitrite and hydro-chloric acid, is caused to flow into a solution of naphthy-
lanine-sulphonic acid, which is kept strongly alkalino until the end of the
reaction, the proportion of the mixture being: one molecule of the sulphonic acid
to two molecules of naphthylamine-sulphonic acid, and to this mixture is added
the quantity of sodic nitrite calculated for two molecules of naphthylamine-
sulphonic acid. Subsequently concentrated hydro-chloric acid is added, while
continually stirring, sufficient to liberate the nitrous acid and give to the whole
liquid a strongly acid reaction. The hexachloride compound thus formed is then
united with a solution of one molecule of B-naphthol in soda-lye, and the solution
carefully kept alkaline until the reaction is completed.
The product, which at the end of the process has the consistence of a broth, is
neutralized by hydro-chloric acid and heated to the boiling point. The colouring
matter is precipitated by common salt and purified by repeated solution and
precipitation. Similar colouring substances are produced by the action of one
molecule of dinzobenzol-sulphonic acid or two molecules of naphthylamino-sulphonic
acid. By employing, instead of B-Naphthol, a-Naphthol or its sulphonic acids, or
resorcin, or generally phenols, the colouring matters obtain tints ranging from
yellow to intenso red. Colouring matters as described are sometimes called
Barmen Scarlets"
CLAIM:
The manufacture of red and yellow colouring matters by treating the hexa-
chlorides of hexnzo-coinpounds of naphthalene-benzol, and other aromatic hydro-
carbons with naphthol, resorcin, and other phenols, and the sulphonic acids of the
saine, substantially as described.
In witness whereof I the said Jasper Wetter have hereunto set my hand and
seal this fourteenth day of September A.D. 1882.