Production of Blue Triphenylmethan Colouring Matters or Dyes.
Year: 1892

page_text: Date of Application, 11th July, 1892
Complete Specification Left, 27th Mar., 1893-Accepted, 6th May, 1893
PROVISIONAL SPECIFICATION.
Production of Blue Triphenylmethan Colouring Matters or Dyes.
We, JOHN RUDOLPH GEIGY of the firm of John Rudolph Geigy & Co. of Basle,
Switzerland, Colour Manufacturers, and Dr. TRAUGOTT SANDMEYER of the
same place Chemist do hereby declare the nature of this invention to be as
follows:-
:-
This invention relates to a blue colouring matter or dye stuff which I term
"crystallized blue" and which is produced from the mono-sulpho acid of
diphenylamine (Beilstein Handbook of Organic Chemistry, edition 1883, page 963)
by condensing two molecules of the same with one molecule of formaldehyde in acid
solution to the disulpho acid of diphenyldiamidodiphenylmethan and oxidising
the said derivative by means of chloride of iron or other oxidising agent such as
bichromate of potassium, chlorate of sodium, chloride of copper, nitrite of sodium
etcetera, in acidulated solution in combination with a further molecule of diphenyl-
amine mono-sulpho acid to the symmetrical trisulpho acid of triphenylpara-
rosaniline.
= one
In carrying out the invention 8.1 kilogrammes (= 3 molecules) of dry sodium
To this
salt of diphenylamine monosulpho acid are dissolved in 100 liters of water.
solution are added 10 liters of hydrochloric acid and 0.75 kilogramme
molecule) of a solution containing 40 per cent. of formaldehyde. The mixture is
then heated in a boiler with reflux-cooler at a temperature of from 100° to
105° centigrade during about half an hour until the combination (or the so-called
condensation) of two molecules of diphenylamine mono-sulpho acid with the
molecule of formaldehyde has been accomplished. A mixture of 16 kilogrammes
of a solution of chloride of iron containing 47 per cent. Fe,Cl, and 100 liters of
water is then gradually and under constant stirring added to the above boiling
solution.
The oxidation being accomplished the colouring matter crystallizes in small
needles exhibiting a bronze-like lustre and dissolving in water with a bright blue
colour.
The crystals are filtered, washed and dissolved in an aqueous solution of
carbonate of sodium in order to remove every trace of iron, and precipitated from
the filtered nearly colourless alkaline solution by means of hydrochloric acid.
Crystallized blue is the sodium salt of the symmetrical trisulpho acid of
triphenylpararosaniline and differs from the ordinary rosaniline blues, which are
mixtures of various colouring matters hitherto known in commerce only as
amorphous powders or lumps, principally by its crystallized condition and by its
uniformity of composition. Crystallized blue, dyes textile fibre a pure blue shade
similar in tint but brighter than the shade produced by the other derivatives of:
triphenylpararosaniline.
A colouring matter of an identical chemical constitution may be obtained by
combined oxidation of one molecule of methyldiphenylamine monosulpho acid with
two molecules of diphenylamine monosulpho acid, the carbon of the methyl group
of the methyldiphenylamine monosulpho acid furnishing the methan carbon of the
triphenylmethan derivative.
In both the above described processes instead of diphenylamine monosulpho acid,
the homologue of it may be taken, the methyldiphenylamine monosulpho acid.

page_text: The colouring matters thus obtained do not crystallize and are very easily soluble
in water.
Dated this 11th day of July 1892.
CAPITAINE & VON HERTLING,
89, Chancery Lane, London, W.C., Agents for the Applicants.
COMPLETE SPECIFICATION.
Production of Blue Triphenylmethan Colouring Matters or Dyes.
We, JOHN RUDOLPH GEIGY of the firmn of John Rudolph Geigy & Co. of
Basle, Switzerland, Colour Manufacturers, and Dr. TRAUGOTT SANDMEYER of
the same place, Chemist, do hereby declare the nature of this invention and in what
manner the same is to be performed to be particularly described and ascertained in
and by the following statement :-
This invention relates to a blue colouring matter or dye which we term
"crystallised blue" and which is produced from the mono-sulpho acid of
diphenylamine (Beilstein Handbook of Organic Chemistry, edition 1883, page 963)
by condensing two molecules of the same with one molecule of formaldehyde in
acid solution to the di-sulpho acid of diphenyldiamidodiphenylmethan and oxidising
the said derivative by means of chloride of iron or other oxidising agent, such as
bichromate of potassium, chlorate of sodium, chloride of copper, nitrite of sodium,
etcetera, in acidulated solution in combination with a further molecule of diphenyl-
amine mono-sulpho acid to the symmetrical tri-sulpho acid of triphenylpara-
rosaniline.
In carrying out the invention 8.1 kilogrammes (= 3 molecules) of dry sodium
salt of diphenylamine mono-sulpho acid are dissolved in 100 liters of water. To
this solution are added 10 liters of hydrochloric acid and 0.75 kilogramme (= one
molecule) of a solution containing 40 per cent. of formaldehyde. The mixture
is then heated in a boiler with reflux, cooler at a temperature of from 100° to
105° centigrade during about half an hour, until the combination (or the so-called
condensation) of two molecules of diphenylamine mono-sulpho acid with the
molecule of formaldehyde has been accomplished. A mixture of 16 kilogrammes
of a solution of chloride of iron containing 47 per cent. FeCl, and 100 liters of
water is then gradually and under constant stirring added to the above boiling
solution.
The oxidation being accomplished, the colouring matter crystallises in small
needles exhibiting a bronze-like lustre and dissolving in water with a bright blue
colour.
The crystals are filtered, washed, and dissolved in an aqueous solution of
carbonate of sodium in order to remove every trace of iron, and precipitated from
the filtered nearly colourless alkaline solution by means of hydrochloric acid.
Crystallised blue is the symmetrical tri-sulpho acid of triphenylpararosaniline
and differs from the ordinary rosaniline blues which are mixtures of various
colouring matters hitherto known in commerce only as amorphous powders or
lumps, principally by its crystallised condition and by its uniformity of composition.
Crystallised blue dyes textile fibre a pure blue shade similar in tint but brighter
than the shade produced by the other derivatives of triphenylpararosaniline.
The neutral sodium salt of the above symmetrical tri-sulpho acid of triphenyl-
pararosaniline obtained by evaporating the neutral solution of the acid in caustic
soda is commercially known as "Helvetia blue."
A colouring matter of an identical chemical constitution may be obtained by
combined oxidation of one molecule of methyldiphenylamine mono-sulpho acid with
two molecules of diphenylamine mono-sulpho acid, the carbon of the methyl group
of the methyldiphenylamine mono-sulpho acid furnishing the methan carbon of the
triphenylmethan derivative.

page_text: In both the above described processes instead of diphenylamine mono-sulpho acid,
the homologue of it may be taken, the methyldiphenylamine mono-sulpho acid.
The colouring matters thus obtained do not crystallise and are very easily soluble
in water.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
The production of blue triphenylmethan colouring matters ordres anotandi. 11.
CAPITAINE & VON HERTLING,
89, Chancery Lane, London, W.C., Agents for the Applicants.