Production of Green and Blue Dyes or Colouring Matters.
Year: 1894

page_text: Date of Application. th Aug., 1894
Complete Specification Left, 1st May, 1895-Accepted, 1st June, 1895
PROVISIONAL SPECIFICATION.
Production of Green and Blue Dyes or Colouring Matters.
I, THOMAS RICHARD SHILLITO of 89 Chancery Lane, in the County of
Middlesex, 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, to be as follows:-
66
This invention relates to the production of dyes or colouring matters and consists
in the substitution of the amide group by hydrogen according to the reaction of
Griess," in the products obtained by condensation of tetramethyldiamidobenzhydrol
with the sulpho acids of primary aromatic amines and in the oxidation of the
leuko sulpho acids thus obtained, into the colouring matters.
In order to obtain the colouring matters of this invention the procedure is as
given in the following instances.
1. 15 kilog. of tetramethyldiamidobenzhydrol and 15 kilog. of a naphtylamine
3, sulphonate of sodium are boiled with 15 kilog. of concentrated sulphuric acid and
300 litres of water until a sample heated with acetate of sodium and acetic acid no
longer turns blue. The resulting product of condensation is precipitated by the
addition of 50 kilog. of acetate of sodium, filtered, and again dissolved in 20 kilog.
of sulphuric acid and 100 litres of water. After cooling, 100 litres of alcohol and a
solution of 6 kil g. of nitrite of sodium in 20 litres of water, are added. The
transformation of the diazo compound is very much accelerated by strewing in a
small quantity of suboxide of copper (Cu₂O). The evolution of nitrogen ceasing,
the solution is diluted with water up to 1000 litres, neutralised, acidulated with
acetic acid and warmed. The leukosulpho acid now separates in heavy lumps which
are dissolved in 40 kilog. of hydrochloric acid and 4000 litres of water and oxidised
by the addition of 35 kilog. of peroxide of lead (PbO₂) of 38 per cent.
Neutralisation is now effected by means of carbonate of sodium, the precipitate
filtered and the colouring matter separated from the carbonate of lead by
dissolving said precipitate in 6000 litres of water of 50° Celsius and kilog. of
carbonate of sodium. The filtered solution is precipitated with common salt and
the colouring matter filtered and dried, forming a black powder of bronze like lustre,
gives a green colour when dissolved in water and dyes wool a deep green shade.
The aqueous solution becomes colourless by heating with ammonia. The colour
appears again by adding acetic acid and if the solution is rather concentrated the
sulpho acid of the colouring matter is precipitated in green flocks.
2. 15 kilog. of tetramethyldiamidobenzhydrol and 11 kilog. of inetanilic acid are
boiled with 10 kilog. of sulphuric acid and 300 litres of water until a sample no
longer shews the presence of hydrol. The product of condensation is precipitated
by neutralisation with soda lye and acidulation with acetic acid, filtered, dissolved
in 20 kilog. of sulphuric acid-and 100 litres of water and to the cold solution are
added 100 litres of alcohol and 6 kilog. of nitrite of sodium in 20 litres of water.
A small quantity of suboxide of copper (Cu₂O) very much accelerates the
transformation of the diazo compound. The solution is now diluted with water up
to 4000 litres, mixed with acetate of sodium until it no longer contains mineral acid
and oxidised by the addition of the necessary quantity of peroxide of lead. When
the oxidation has been accomplished, neutralisation is effected with carbonate of
sodium, the solution containing the colouring matter filtered from the sulphate of
lead and evaporated after it has been again slightly acidulated, until the colouring

page_text: matter begins to separate completely. The colouring matter thus obtained forms a
bronze like powder dissolving in water with a blue shade, wool and silk being dyed
from a slightly acidulated bath. By the addition of soda lye or acetic acid the
solution is not altered, but mineral acids cause it to turn from blue to green and
yellow.
:
If, in place of metanilic acid the orthotoluidinparasulpho acid (NH, CH,
SO,H12:5) is employed a very similar colouring matter is obtained,
distinguished from that above mentioned by its greater solubility in water.
Dated this 9th day of August 1894.
THOMAS R. SHILLITO,
89, Chancery Lane, London, W.C.
I, THOMAS RICHARD SHILLITO of 89 Chancery Lane, in the County of
Middlesex, 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, 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 dyes or colouring matters and consists
in the substitution of the amido group by hydrogen according to the reaction of '
"Griess" in the products obtained by condensation of the tetramethyldiamidobenz-
hydrol with the sulpho acids of primary aromatic amines and in the oxidation of
the leuko sulpho acids thus obtained into the colouring matters.
In order to obtain the dyes or colouring matters of this invention the following
procedure is given by way of example.
1. 15 kilog. of tetramethyldiamidobenzhydrol and 15 kilog. of a naphtylamine
ẞ sulphonate of sodium are boiled with 15 kilog. of concentrated sulphuric acid and
300 litres of water until a sample heated with acetate of sodium and acetic acid no
longer turns blue. The resulting product of condensation is precipitated by the
addition of 50 kilog, of acetate of sodium, filtered, and again dissolved in 20 kilog.
of sulphuric acid and 100 litres of water. After cooling, 100 litres of alcohol and
a solution of 6 kilog. of nitrite of sodium in 20 litres of water are added. The
transformation, then soon beginning, of the diazo" compound is very much
accelerated by strewing in a small quantity of suboxide of copper (Cu2O). The
evolution of nitrogen ceasing, the solution is diluted with water up to 1000 litres,
neutralised, acidulated with acetic acid and warmed. The leucosulpho acid now
separates in heavy lumps which are dissolved in 40 kilog. of hydrochloric acid and
4000 litres of water and oxidised by the addition of 35 kilog. of peroxide of
lead (PbO2) of 38 per cent. Neutralisation is now effected by means of carbonate
of sodium, the precipitate filtered and the colouring matter separated from the
carbonate of lead by dissolving said precipitate in 6000 litres of water of 50° Celsius'
and kilog. of carbonate of sodium. The filtered solution is precipitated with
coniinon salt and the colouring matter 'filtered' and dried, forming a black powder
of bronze like lustre, gives a greèn colour when dissolved in water and dyes wool a
deep green shade. The aqueous solution becomes colourless by heating with
ammonia. The colour appears again by adding acetic acid and if the solution is
rather concentrated, the sulpho acid of the colouring matter is precipitated in green
flocks.
.
"
2. 15 kilog of tetramethyldiamidobenzhydrol and 11 kilog. of metanilic acid are
boiled with 10 kilog. of sulphuric acid and 300 litres of water until a sample no
longer shews the presence of hydrol. The product of condensation is precipitated
A

page_text: by neutralisation with soda lye and acidulation with acetic acid, filtered, dissolved in
20 kilog. of sulphuric acid and 100 litres of water and the cold solution has added to
it 100 litres of alcohol and 6 kilog. of nitrite of sodium in 20 litres of water.
A small quantity of suboxide of copper (Cu,O) very much accelerates the
transformation of the diazo compound. The solution is now diluted with water
up to 4000 litres, mixed with acetate of sodium until it no longer contains mineral
acid and oxidised by the addition of the necessary quantity of peroxide of lead.
When the oxidation has been accomplished neutralisation is effected with carbonate
of sodium, the solution containing the colouring matter filtered from the sulphate of
lead and evaporated after it has been again slightly acidulated, until the colouring
matter begins to separate completely. The colouring matter thus obtained forms
a bronze like powder dissolving in water with a blue shade, wool and silk being
dyed from a slightly acidulated bath. By the addition of soda lye or acetic acid
the solution is not altered, but mineral acids cause it to turn from blue to green and
yellow.
:
If, in place of metanilic acid the orthotoluidinparasulpho acid (NH, CH,
SO,H=1:2:5) is employed a very similar colouring matter or dye is obtained,
distinguished from that above referred to by its greater solubility in water.
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 production of green and blue dyes or colouring matters in the manner
substantially as described.
Dated this lot dore of Mar 1905
THOMAS R. SHILLITO,
89, Chancery Lane, London, W.C.