Improvements in the Manufacture of Greenish Blue Colouring Matters or Dyes of the Malachite Green Series.
Year: 1896

page_text: Date of Application, 6th Mar., 1896
Complete Specification Left, 26th Nov., 1896-Accepted, 24th ec., 1896
Improvements in the Manufacture of Greenish Blue Colouring
Matters or Dyes of the Malachite Green Series.
I, 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:-
In the Specification of the German Patent No. 80,982 granted to my foreign
correspondents, is described a process of producing the ortho sulpho acid of the
colouring matter generally known under the name of malachite green. At the
same time said correspondents have observed that with the entrance of the sulpho
group into the molecule in the ortho position to the methane carbon the colouring
matters receive all the excellent qualities of the so called patent blue dye stuff's
such as blue tone, fastness against alkalies and the property of furnishing very even
shades on wool.. The said correspondents thus proved that the properties of the
colouring matters belonging to the patent blue series as well as those of their
aforesaid patent are based upon the same fact, namely, upon the said ortho position
of the sulpho group. This observation led to the conclusion that similar colouring
matters may be obtained by starting from the ortho sulpho acid of the benzaldehyde,
which was then unknown, but which my foreign correspondents succeeded in
obtaining by treating the ortho chlorbenzaldehyde in an autoclave with an aqueous
solution of neutral sulphite of soda at a temperature of from 190° to 200° Celsius,
for about six hours. The ortho sulpho acid of benzaldehyde thus obtained can be
very easily condensed with the different alkylated aromatic amines and their sulpho
acids. The leuko sulpho acids thus obtained, furnish by oxidation very valuable
greenish blue colouring matters of remarkable fastness against alkalies.
EXAMPLE 1.
186 kilos. of a solution containing 10 per cent. of the above mentioned ortho
sulpho acid of benzaldehyde is boiled with 30 kilos. of dimethylaniline and kilos..
of sulphuric acid for 15 hours. Carbonate of soda is then added and the
dimethylaniline which has remained unacted upon, distilled off. The solution is
now diluted up to 5000 litres, acidulated by hydrochloric or acetic acid and the
product, which in chemical language may be called the leuko sulpho acid of the
colouring matter of this invention, is then by means of the calculated quantity of
peroxide of lead' submitted to an oxidising process analogous to that which is
generally used lor converting the leuko bases of malachite green or of similar dye
stuffs into their corresponding colouring matters. The sulphate of lead being-
filtered off, the solution which has been made alkaline by addition of ammonia is
evaporated to dryness.
EXAMPLE 2.

page_text: with hydrochloric acid is oxidised by addition of 100 kilos. of a paste containing
30 per cent. of peroxide of lead; then saturated with ammonia, filtered, and
evaporated to dryness. The colouring matter thus obtained forms a bronze like
powder, soluble in water with blue colour and dyeing wool in an acidulated bath in
very pure greenish blue shades.
Dated this 6th day of March 1896.
THOMAS R. SHILLITO,
89 Chancery Lane, London, W.C.
Improvements in the Manufacture of Greenish Blue Colouring
Matters or Dyes of the Malachite Green Series.
I, THOMAS RICHARD SHILLITO of 89 Chancery Lane, London, W.C., Engineer,
do hereby declare the nature of this invention-a communication to me from abroad
by Messieurs John Rudolph Geigy & Co., of Basle, Switzerland, Colour Manu-
facturers, and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
In the Specification of the German Patent No. 80,982 granted to my foreign
correspondents, is described a process of producing the ortho sulpho acid of the
colouring matter generally known under the name of malachite green; at the same
time said correspondents have made the surprising observation that with the
entrance of the sulpho group into the molecule in the ortho position to the methane
carbon, the colouring matters obtain all the excellent qualities of the so called
patent blue dye stuffs, such as blue tone, fastness against alkalies and the property
of furnishing very even shades on wool. The said correspondents thus proved that
the properties of the colouring matters belonging to the patent blue series as well
as those of the aforesaid patent are based upon the same fact, namely, upon the
above named ortho position of the sulpho group. From this observation they
concluded that similar colouring matters may be obtained by starting from the
orthosulpho acid of the benzaldehyde, which was then unknown, but which said
correspondents succeeded in obtaining by treating the orthochlorbenzaldehyde in
an antoclave with an aqueous solution of neutral sulphite of soda at a temperature
of from 190° to 200° Celsius for about eight hours. The ortho sulpho acid of
benzaldehyde thus obtained can be very easily condensed with the different
alkylated aromatic amines and their sulpho acids. The leukosulpho acids thus
obtained, furnish by oxidation very valuable greenish blue colouring matters of
remarkable fastness against alkalies.
EXAMPLE 1.
186 kilogr. of an acidulated solution containing 10 per cent. of the above
mentioned orthosulpho acid of benzaldehyde is boiled with 30 kilogr. of dimethyl-
aniline and 3 kilogr. of sulphuric acid for 15 hours. Carbonate of soda is then
added and the dimethylaniline which has remained unacted upon, distilled off. The
solution is now diluted up to 5000 liters, acidulated by hydrochloric or acetic acid
and the product which in chemical language may be called the leukosulpho acid of
the colouring matter of this invention, is then by..means of the calculated quantity
of peroxide of lead, subraitted-to an oxidising process analogous to that which is
generally used for converting the leuko bases of malachite green or of similar dye-
stuff into their corresponding colouring matters.
The sulphate of lead precipitated by means of Glauber salt is fittered off an
19

page_text: the solution which has been made alkaline by addition of ammonia, is evaporated.
to dryness.
EXAMPLE 2.
186 kilogr. of an acidulated solution containing 10 per cent. of the orthosulpho
acid of benzaldehyde is boiled with 60 kilogr. of ethyl-benzylanilinemonosulpho
acid for 15 hours. The solution after having been diluted up to 5000 liters and
acidulated with hydrochloric acid, is oxidised by addition of 100 kilogr. of a paste
containing 30 per cent. of peroxide of lead. The lead precipitated by addition of
Glauber salt is filtered off and the solution saturated with ammonia is evaporated
to dryness. The colouring matter thus obtained forms a bronze like powder,.
soluble in water with blue colour and dyeing wool in an acidulated bath in very
pure greenish blue shades.
Having now particularly described and ascertained the nature of said invention,.
as communicated to me by my foreign correspondents and in what manner the
same is to be performed, I declare that what I claim is :-
The production of greenish blue colouring matters by condensation of benzal-
dehydeorthosulpho acid with dimethylaniline, diethylaniline, methylbenzylaniline-.
monosulpho acid, ethylbenzylanilinemonosulpho acid and oxidation of the leuko--
sulpho acids thus obtained into the colouring matters, substantially as described.
Dated this 26th day of November 1896.
THOMAS R. SHILLITO,
89 Chancery Lane, London, W.C..