Production of a Yellow Colouring Matter or Dye.
Year: 1890

page_text: Date of Application, 20th Oct., 1890
Complete Specification Left, 22nd June, 1891-Accepted, 25th July, 1891
PROVISIONAL SPECIFICATION.
Production of a Yellow Colouring Matter or Dye.
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 relates to the production of a yellow colouring matter or dye by
the action of sulphur on tetramethyldiamidothiobenzhydrol or tetramethyldiamido-.
benzhydrol in the presence of ammonia and muriate of ammonia.
As an example of the method of carrying out the invention, 14.3 kilogrammes
of tetramethyldiamidothiobenzhydrol or 13.5 kilogrammes of tetramethyldiamido-
benzhydrol and 1.6 kilogrammes of sulphur are heated in a digester or autoclave
to 140° Celsius with oil bath and inlet and outlet pipe. Addition is then made of
a mixture of 120 kilogrammes of common salt and 7 kilogrammes of muriate of
ammonia in powder at the aforesaid temperature of 140° Celsius. The temperature
of the oil bath is raised to 175° and a current of dry ammonia then passed
rapidly through the apparatus under a low pressure whilst the mass is constantly
stirred during seven or eight hours.
In order to separate the excess of ammonia from the sulphuretted hydrogen, the
gases are passed through caustic soda. By this means the sulphuretted hydrogen
is absorbed and the ammonia may be passed into water and again employed in
manufacture.
The product of the reaction forms a brown yellow mass, which, in order to
remove the common salt is first treated with a small quantity of cold water. The
undissolved portion containing the colouring matter requires for its purification
merely to be dissolved in hot water and precipitated from the filtered solution by
common salt,
Cotton mordanted with tannin is dyed in a pure yellow shade by the colour thus
obtained.
Tetramethyldiamidothiobeny hydrol may be made as follows:
25.4 kilogrammes of tetramethyldiamidodiphenylmethane is dissolved in 40 kilo-
grammes of concentrated muriatic acid and 1000 litres of water. This solution
is cooled with ice and whilst stirring addition is made thereto of a mixture of
80 kilogrammes of 30% bioxide of lead paste with 100 litres of water. When
the oxidation is finished, the lead is precipitated with 35 kilogrammes of crystallised
Glauber salt and the liquid then slightly heated and filtered. By means of a
solution of caustic soda the tetramethyldiamidobenzhydrol is now precipitated. To
obtain the thio compound it is pressed and dissolved in spirit, then slightly acidulated
with acetic acid and saturated with sulphuretted hydrogen. Some time afterwards
the thio hydrol separates, first in the form of oily drops and later in that of a
yellowish crystalline mass.
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page_text: COMPLETE SPECIFICATION.
Production of a Yellow Colouring Matter or Dye.
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 relates to the production of a yellow colouring matter or dye by
the action of sulphur on tetramethyldiamidothiobenzhydrol or tetramethyldiamido-
benzhydrol in the presence of ammonia and muriate of ammonia.
As an example of the method of carrying out the invention, 14.3 kilogrammes
of tetramethyldiamidothiobenzhydrol or 135 kilogrammes of tetramethyldiamido-
benzhydrol and 1.6 kilogrammes of sulphur are heated to about 140° Celsius in a
digester or autoclave fitted with an inlet and outlet pipe and contained in an oil
bath. Addition is then made of a mixture of 120 kilogrammes of common salt
and 7 kilogrammes of muriate of ammonia in powder at the aforesaid temperature
of 140° Celsius. The temperature of the oil bath is raised to 175° and a current
of dry ammonia then passed rapidly through the apparatus under a low pressure
whilst the mass is constantly stirred during seven or eight hours.
In order to separate the excess of ammonia from the sulphuretted hydrogen, the
gases are passed through caustic soda. By this means the sulphuretted hydrogen
is absorbed and the ammonia may be passed into water and again employed in
manufacture.
The product of the reaction forms a brown yellow mass which, in order to
remove the common salt is first treated with a small quantity of cold water. The
undissolved portion containing the colouring matter requires for its purification
merely to be dissolved in hot water and precipitated from the filtered solution by
common salt.
Cotton mordanted with tannin is dyed in a pure yellow shade by the colour thus
obtained.
Tetramethyldiamidothiobenzhydrol may be made as follows:
25.4 kilogrammes of tetramethyldiamidodiphenylmethane are dissolved in 40 kilo-
grammes of concentrated muriatic acid and 1000 litres of water. This solution
is cooled with ice and, whilst stirring, addition is made thereto of a mixture of
80 kilogrammes of 30% bioxide of lead paste with 100 litres of water. When
the oxidation is finished, the lead is precipitated with 35 kilogrammes of crystallised
Glauber salt and the liquid then slightly heated and filtered. By means of a
solution of caustic soda the tetramethyldiamidobenzhydrol is now precipitated. To
obtain the thio compound, it is pressed and dissolved in spirit, then slightly
acidulated with acetic acid and saturated with sulphuretted hydrogen. Some
time afterwards the thio-hydrol separates, first in the form of oily drops and later
in that of a yellowish crystalline mass.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is:
The manufacture of a yellow colouring matter or dye by treating tetramethyl-
diamidobenzhydrol or tetramethyldiamidothiobenzhydrol with sulphur and ammonia
in the presence of muriate of ammonia and common salt substantially as described.
Dated this 22nd day of June 1891.
T. R. SHILLITO,
89, Chancery Lane, London, W.C., Agent for the Applicant.