Manufacture of Diaethyldibenzyldiamido-diphenylmethan Disulpho Acid and Violet Dye Stuffs therefrom.
Year: 1890

page_text: Date of Application, 31st Dec., 1890.
Complete Specification Left, 14th Sept., 1891-Accepted, 24th Oct., 1891
PROVISIONAL SPECIFICATION.
Manufacture of Diaethyldibenzyldiamido-diphenylmethan Disulpho
Acid and Violet Dye Stuffs therefrom.
I, JOHN RUDOLPH GEIGY of the firm of John Rudolph Geigy & Co., of Basle,
Switzerland, Colour Manufacturers, do hereby declare the nature of this invention
to be as follows:-
This invention is based upon the discovery that aethylbenzylaniline sulpho-acid
acting upon formaldehyde forms diaethyldibenzyldiamido-diphenylmethan disulpho
acid a compound of value for the production of violet dye stuffs the manufacture of
which can be carried out in four operations in the same watery solution. These
operations are:
1. Condensation of aethylbenzylaniline sulpho acid with formaldehyde.
2. Oxidation of diaethyldibenzyldiamido-diphenylmethan disulpho acid thus
obtained into diaethyldibenzyldiamidobenzhydrol disulpho acid.
3. Condensation of the diaethyldibenzyldiamidobenzhydrol disulpho acid with.
dimethyl or diaethylaniline into dimethyldiaethyldibenzyl or tetraaethyldibenzyl-
paraleukaniline disulpho acid.
4. Oxidation of these leuko-disulpho acids into sulpho acids of the colouring
matter.
As an example of the method of carrying out the invention, 22 kilogrammes of
aethylbenzylaniline is heated with 88 kilogrammes of sulphuric acid monohydrate
to 180° Celsius until it is completely soluble in alkali, then 500 litres of water are
added, the solution neutralised with 95 kilogrammes of calcinated soda and again
acidulated with 20 kilogrammes of concentrated muriatic acid. This is boiled for
half an hour with 5 kilogrammes of 30 per cent. formaldehyde. By addition of
15 kilogrammes of calcinated soda the diaethyldibenzyldiamido-diphenylmethan
disulpho acid thus formed is kept in solution and diluted with water up to
1000 litres.
2. 200 litres of this solution is diluted with 200 litres of water and mixed whilst
stirring with 5-3 kilogrammes of 45 per cent. bi-oxide of lead. Gradually a mixture
of 6 kilogrammes of muriatic acid and 100 litres of water is added and the oxidation
to hydrol effected in about one hour.
3. Immediately afterwards 1.2 kilogrammes of dimethyl or 1.5 kilogrammes of
diaethylaniline is added. The condensation of these bases with the hydrol disulpho
acid is somewhat rapid. The end of the reaction is visible when the green colour
turns into violet.
4. The leuko-disulpho acid is now oxidated by addition of 5-3 kilogrammes of
a 45 per cent. paste of bi-oxide of lead. To develope the colour the solution is
constantly stirred for five hours, then filtered, and the dye stuff precipitated with
common salt forms when dry a blue violet powder easily soluble in water and dyeing
wool in fine violet shades.
Dated this 31st day of December 1890.
T. R. SHILLITO,
89, Chancery Lane, London, W.C., Agent for the Applicant.

page_text: COMPLETE SPECIFICATION.
Manufacture of Diaethyldibenzyldiamido-diphenylmethan Disulpho
Acid and Violet Dye Stuffs therefrom.
I, JOHN RUDOLPH GEIGY of the firm of John Rudolph Geigy & Co. of Basle,
Switzerland, Colour Manufacturers, 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 is based upon the discovery that aethylbenzylaniline sulpho acid
acting upon formaldehyde forms diaethyldibenzyldiamido-diphenylmethan disulpho
acid, a compound of value for the production of violet dye stuffs the manufacture
of which can be carried out in four operations in the same watery solution.
These operations are :-
1. Condensation of aethylbenzylaniline sulpho acid with formaldehyde.
2. Oxidation of diaethyldibenzyldiamido-diphenylmethan disulpho acid thus
obtained into diaethyldibenzyldiamidobenzhydrol disulpho acid.
3. Condensation of the diaethyldibenzyldiamidobenzhydrol disulpho acid with
dimethyl or diaethylaniline into dimethyldiaethyldibenzyl or tetraaethyldibenzyl-
paraleukaniline disulpho acid.
4. Oxidation of these leuko-disulpho acids into sulpho acids of the colouring
matter.
As an example of the method of carrying out the invention 22 kilogrammes. of
aethylbenzylaniline is heated with 88 kilogrammes of sulphuric acid. monohydrate
to 180° Celsius until it is completely soluble in alkali, then 500 litres of water are
added, the solution neutralised with 95 kilogrammes of calcinated soda and again
acidulated with 20 kilogrammes of concentrated muriatic acid. This is boiled for
an hour with 5 kilogrammes of 30 per cent. formaldehyde. By addition of 15 kilo-
grammes of calcinated soda the diaethyldibenzyldiamido-diphenylmethan disulpho
acid thus formed is kept in solution and diluted with water up to 1000 litres.
2. 200 litres of this solution is diluted with 400 litres of water and mixed whilst
stirring with 5-3 kilogrammes of a paste containing 45 per cent. bi-oxide of lead.
Gradually a mixture of 6 kilogrammes of muriatic acid and 100 litres of water is
added and the oxidation to hydrol effected in about 2 hours.
3. Immediately afterwards 1-2 kilogrammes of dimethyl or 1.5 kilogrammes of
diaethylaniline is added; the mixture is heated up to 35° Celsius and the end of
the condensation of these bases with the hydrol disulpho acid, taking half an hour,
is visible when the green colour turns into violet.
4. The leuko-disulpho acid is now oxidated by addition of 5.3 kilogrammes of a
paste containing 45 per cent. bioxide of lead. To develope the colour the solution
is constantly stirred for five hours, then filtered and the dye stuffs precipitated with
common salt.
Both combinations form, when dry, a blue violet powder easily soluble in water
and dyeing wool in fine violet shades.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :
The manufacture of diaethyldibenzyldiamido-diphenylmethan disulpho acid and
violet dye stuffs therefrom substantially as described.
Dated this 14th day of Cantombar 1901
T. R. SHILLITO,
89, Chancery Lane, London, W.C., Agent for the Applicant.