Improvements in the Production of Red Colouring Matters.
Year: 1896

page_text: Date of Application, 24th Aug., 1896
Complete Specification Left, >th May, 897-Accepted, 12th June, 1897
PROVISIONAL SPECIFICATION.
Improvements in the Production of Red Colouring Matters.
1, THOMAS RICHARD SHILLITO of 89 Chancery Lane, London, W.C., Engineer
and Patent Agent, do hereby declare the nature of this invention-a communication
to me from abroad by Messieurs John Rudolph Geigy & Co. of Basle, Switzerland,
Colour Manufacturers-to be as follows:-
It is generally known that the phtaleines of the alkylated metaamido phenols-
the so called rhodamines-belong to that class of the triphenylmethane colours
which are distinguished by a remarkable fastness against the action of alkalies like
the colours of the patent blue series. In a former patent specification my
correspondents have shown that the remarkable properties of the patent blue,
especially the fastness to alkalies, are based upon the position of the sulpho group
in ortho to the methane carbone. From this they concluded that in the rhodamine
colours the fastness is based upon the same fact, i.e., the ortho position of the
carboxyl group to the methane carbone. In fact my correspondents have found
that the carboxyl group in the rhodamines may be substituted by the sulpho group
without any diminution of the fastness of the new colouring matters thus obtained,
the production of which is shortly as follows:-
Benzaldehydeorthosulpho acid is condensed with alkylated metaamido phenoles
in slightly acidulated aqueous solution by a few hours boiling; the dihydroxylated
alkyldiamidotriphenylmethanemonosulpho acids thus obtained are evaporated to
dryness, then treated with water removing agents, for instance, concentrated
sulphuric acid, in order to remove one molecule of water and finally the derivates
of the triphenylmethanoxyde thus formed, are oxydised in aqueous solutions to
colouring matters, by means of one of the usual oxydising agents such as bichroinate.
of potash, peroxyde of lead, chloride of iron, etcetera.
The process for preparing the new colouring matters is more fully described in
the following example:-
37 kilos. of a solution containing 10 per cent. of benzaldehydeorthosulpho acid is
boiled with 7 kilos. of diethylmetaamidophenol for 8 hours; the solution of the
tetraethyldiamidodioxytriphenylmethanemonosulpho acid thus obtained is then
evaporated to dryness, the remainder is pulverised and heated with 40 kilos. of
concentrated sulphuric acid for an hour to from 135° to 140° Celsius, then diluted
with 400 liters of water and the cold solution boiled and filtered. To this is then
added 18 kilos. of a solution of chloride of iron containing 33 per cent. Fe 2 C16
and this product heated for 4 or 5 hours up to from 80° to 90° Celsius. The
colouring matter thus formed partly separates in crystals, partly it remains in
solution and can be precipitated by addition of common salt; it is filtered from the
acid solution, washed with a bot concentrated solution of common salt in order to
remove the adbering iron salts and finally boiled up with aqueous ammonia.
By this treatment the colouring matter is separated from other red colouring
matters of the same shade but soluble in alkalies; the pure product is filiored,
washed with water, dried, and crystallised from alcohol or acetic acid, and is thus
obtained as a greenish crystalline powder, scarcely dissolving in cold water, a little
better in hot water, very easily soluble in alcohol and acetic acid with a blueish
red shade.

page_text: All these solutions especially the alcoholic one, shew a very bright yellowish red
fluorescence. An addition of ammonia or soda lye to the aqueous solution does not
change the colour. In hydrochloric acid and diluted sulphuric acid the colouring
matter is very easily soluble with a yellowish red shade turning to blueish red by
addition of water. From these solutions wool and silk are dyed very pure blueish
red shades perfectly fast to alkalice.
If in the above example, instead of diethylmetaamidophenol, the dimethylmet-
amidophenol is employed, there is obtained a very similar colouring matter differing
only from the first one by its being less soluble and dissociating very easily from
its solution in mineral acide.
The described process may be varied in the way that the condensation of the
benzaldehydeorthosulpho acid with the alkylated amidophenol and the removal of
one molecule of water in the firstly formed product of condensation are accomplished
at the same time. For this purpose the calculated quantities of the above
mentioned dry substances are dissolved in concentrated sulphuric acid. At first
heat is applied up to 100° Celsius during a few hours and finally up to from 130°
to 140° Celsius, the further working up being the same as set forth in the
example.
Dated this 24th day of August 1896.
THOMAS R. SHILLITO,
89 Chancery Lane, London, W.C.
COMPLETE SPECIFICATION.
Improvements in the Production of Red Colouring Matters.
I, THOMAS RICHARD SHILLITO of 89 Chancery Lane, London, W.C., Engineer
and Patent Agent, do hereby declaro the nature of this invention and in what
manner the same is to be performed, a communication to me from abroad by
Messieurs John Rudolph Geigy & Co. of Basle, Switzerland, Colour Manufacturers,
to be as follows:-
It is generally known that the phtaleines of the alkylated metaamido phenols-
the so called rhodamines-belong to that class of the triphenylmethane colours
which are distinguished by a remarkable fastness against the action of alkalies
like the colours of the patent blue series. In a former patent specification my
correspondents have shewn that the remarkable properties of the patent bluo,
especially the fastness to alkalies, are based upon the position of the sulpho group
in ortho to the methane carbon. From this they concluded that in the rhodamine
colours the fastness is based upon the same fact, that is, the ortho position of the
carboxyl group to the methane carbone. In fact ny correspondents have found
that the carboxyl group in the rhodamines may be substituted by the sulpho group
without any diminution of the fastness of the colouring matters thus obtained, the
production of which is shortly as follows:-
Benzaldehydeorthosulpho acid is condensed with alkylated metaamidophenolos
in slightly acidulated, or better, in alkaline aqueous solution, by a few hours
boiling the dihydroxylated alkyldiamidotriphenylmethane mono sulpho acids thus
obtained are evaporated to dryness, then treated with water removing agents, for
instance, concentrated sulphuric acid, in order to remove one molecule of water and
finally the derivatives of the triphenylmethan oxide thus formed, are oxidised in
aqueous solution to colouring matters by muaus of one of the usual oxidising agents
such as bichromate of potash, peroxyde of lead, chloride of iron, etcetera.
The process for preparing the new colouring matters is more fully described in
the following example:-
37 kilos. of a solution containing 10 per cent. of benzaldehydeorthosulpho acid is

page_text: boiled with 7 kilos. of diethylmetaamidophenol and 1 kilo. of carbonate of soda for
8 hours; the solution of the tetraethyldiamidodioxytriphenylmethane monosulpho
acid thus obtained, is then evaporated to dryness, the remainder is pulverised and
heated with 40 kilos. of concentrated sulphuric acid for from 3 to 5 hours to from
135° to 145° Celsine, then diluted with 400 liters of water and the cold solution
boiled and filtered. To this is then added 18 kilos, of a solution of ahloride of iron
containing 33 per cent. Fe 2 C16 and this product heated for 4 or 5 hours up to
from 90° to 100° Celsius. The colouring matter thus formed partly separates in
crystals, partly it remains in solution and can be precipitated by addition of
common salt, it is filtered from the acid solution, washed with a hot concentrated
solution of common salt in order to remove the adhering iron salts and finally boiled
up with aqueous ammonia. By this treatment the colouring matter is separated
from other red colouring matters of the same shade but soluble in alkalics; the
pure product is filtered, washed with water, dried, and crystallised from alcohol or
acetic acid, and is thus obtained as a greenish crystalline powder, scarcely dissolving
in cold water, a little better in hot water, very easily soluble in alcohol and acetic
acid with a blueish red shade.
All these solutions especially the alcoholic one, alew a very bright yellowish red
fluorescence. An addition of ammonia or soda lye to the aqueous solution does not
change the colour. In hydrochloric acid and diluted sulphuric acid, the colouring
matter is very easily soluble with a yellowish red abado turning to blueish red by
addition of water. From these solutions, wool and silk are dyed very pure blueish
red shades perfectly fast to alkalies.
If, in the above examplo, instead of diethylmetaamidophenol, the dimethylmeta-
amidophenol is employed, there is obtained a very similar colouring matter differing
only from the first one, by its being less soluble and dissociating very easily from
its solution in mineral acids.
The described process may he varied in the way that the condensation of the
benzaldehydeorthosulpho acid with the alkylated amidophenol and the removal of
one molecule of water in the firstly formed product of condensation are accomplished
at the same time. For this purpose, the calculated quantities of the above
mentioned dry substances are dissolved in concentrated sulphuric acid. At first,
heat is applied up to 100° Celsius during a few hours and finally up to from 135°
to 145° Celsius, the further working up being the same as set forth in the
example.
Having now particularly described and ascertained the nature of said inveu-
tion and in what manner the same is to be performed, as communicated to me by
my foreign correspondents, I declare that what I claim is :-
1. The production of new blueish red colouring matters fast against the action
of alkalies, and belonging to the triphenylmethane series, by condensation of
benzaldehydeorthosulpho acid with mono or dialkylated (in the amido group)
metaamidophenols, by further treating the thus obtained dihydroxylated di or
tetraalkyldiamidotriphenylmethane mono sulpho acids with water removing agents,
especially sulphuric acid, and by final transformation of the formed derivatives
of triphenylmethan oxyde by oxidation to colouring matters substantially as
described.
2. As new compounds the new colouring mattera referred. to in Claim 1,
substantially as described.
Dated tho 1
2007
THOMAS R. SHILLITO,
89 Chancery Lane, London, W.C.