IMPROVEMENTS IN THE MANUFACTURE OF BLUE COLORING MATTER
Year: 1874

page_text: LETTERS PATENT to Edouard George Peter Thomas, of the Star
Chemical Works, Brentford, in the County of Middlesex, for the
Invention of "IMPROVEMENTS IN THE MANUFACTURE OF BLUE COLORING
MATTER." A communication from abroad by Charles Adam Girard,
of 20, Rue des Ecoles, Paris, in the Republic of France.
Sealed the 29th December 1874, and dated the 4th July 1874.
PROVISIONAL SPECIFICATION left by the said Edouard George Peter
Thomas at the Office of the Commissioners of Patents, with his
Petition, on the 4th July 1874.
I, EDOUARD GEORGE PETER THOMAS, of the Star Chemical Works,
Brentford, in the County of Middlesex, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN THE MANUFACTURE OF BLUE
COLORING MATTER," to be as follows:-
The Invention consists in the manufacture of blue coloring matters
from mixed tertiary monamines, as hereinafter described, namely,
methyldiphenylamine base, distilling between 285° centigrade and 290°;.
ethyldiphenylamine base, distilling between 292° and 297°, amyldiphe-

page_text: nylamine base, distilling between 330° and 340°. These bases heated,
either mixed together or separately with oxalic acid (two parts oxalic
acid to one part of the base), during from 10 to 15 hours at a tem-
perature between 110° and 115° change into blue coloring matters. To
purify these blue coloring matters it is sufficient to treat them first with
water to remove excess of oxalic acid, then with a neutral solvent, such
as petroleum, ether, or alcohol, diluted with water, in which the bases
(mixed tertiary monamines) are soluble, whilst the blue coloring matters
are almost entirely insoluble. These blue coloring matters, treated with
from 2 to 5 times their weight of concentrated sulphuric acid, and
hcated to from 60° to 120°, yield sulpho-conjugated combinations soluble
in water. These sulpho-conjugated combinations may also be obtained
by the direct reaction of a mixture of oxalic and sulphuric acid upon the
mixed tertiary monamines.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Edouard George Peter Thomas in the Great Seal 30
Patent Office on the 4th January 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDOUARD
GEORGE PETER THOMAS, of the Star Chemical Works, Brentford, in the
County of Middlesex, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourth day of July, in the year of our Lord
One thousand eight hundred and seventy-four, in the thirty-eighth year
of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said Edouard George Peter Thomas, Her special license
that I, the said Edouard George Peter Thomas, my executors, admini-
strators, and assigns, or such others as I, the said Edouard George
Peter Thomas, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom
of Great Britain and Ireland, the Channel Islands, and Isle of Man,
an Invention for "IMPROVEMENTS IN THE MANUFACTURE OF BLUE COLORING
MATTER," (a communication to me from abroad by Charles Adam Girard,
of 20, Rue des Ecoles, Paris, in the Republic of France,) upon the con-
dition (amongst others) that I, the said Edouard George Peter Thomas,
my executors or administrators, by an instrument in writing under my,
or their, or one of their hands and seals, should particularly describe
and ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Edouard George Peter Thomas, do
hereby declare the nature of the said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement thereof, that is to say :-
The Invention consists in the manufacture of blue coloring matter
from mixed tertiary monamines, as herein-after described, namely,
methyldiphenylamine base, distilling between 285° and 290° centrigrade;
ethyldiphenylamine base, distilling between 292° and 297°; amyldiphe..
nylamine base, distilling between 330° and 340°. These bases heated,
either mixed together or separately with oxalic acid (two parts oxalic
acid to one part of the base), during from 10 to 15 hours at a tem-
perature between 110° and 115° change into blue coloring matters, or
5 the temperature may be raised even to 130 degrees without injury to
the product.

page_text: purify these blue coloring matters it is sufficient to treat them first with
water to remove excess of oxalic acid, then with a neutral solvent, such
as petroleum, ether, or alcohol diluted with water, in which the bases
(mixed tertiary monamines) are soluble, whilst the blue coloring matters
'are almost entirely insoluble.
The excess of methyldiphenylamine, ethyldiphenylamine, or amyl-
diphenylamine, may also be easily removed by treatment in a large
still, heated by means of a double bottom, through which a current of
steam is caused to pass. The mass is constantly agitated by means of a
mechanical agitator, and a tube entering into the interior of the still and
passing to the bottom permits a strong current of steam to be passed
into it. The crude mass having been washed with water is saturated
with a slight excess of caustic soda. It is heated by means of the double
bottom, and the heat is continued for some time whilst the mass is
agitated, then a current of steam is passed through it. The still com-
municates with a condensing coil, round which cold water circulates.
The water and the bases which pass off with the current of steam are
collected and separated by decantation. When the water passing over
contains no more of the tertiary monamies the mass to purify it
further is treated in the still itself with strong alcohol. It is allowed
to cool and is decanted. The purification is finished by washing with
alcohol diluted with an equal volume of water. The solution is filtered,
and the blue collected and dried.
Another method of treatment consists in removing the excess of
tertiary monamines by means of successive washings with concentrated
'sulphuric acid. The crude mass is dissolved cold in this acid (one part
'crude blue to four parts sulphuric acid, 66 Beaumé). It is diluted with
its own volume of water, then filtered through sand filters. Two or
three washings will suffice to remove the excess of tertiary monamines.
Finally the pulverulent mass is washed with hot water; it is decanted or
'filtered, and dried. The blue matters after these treatments can be
easily transformed into blues soluble in water, it is sufficient for this
purpose to heat them for several hours at a temperature of from 50° to
110° with several times their weight of concentrated sulphuric acid,
according to the combination of blue and acid which it is desired to
obtain. They yield sulpho-conjugated combinations soluble in water.
These sulpho-conjugated combinations may also be obtained by the

page_text: 1 to 2 parts of tertiary monamines (bases).
1 to 2 parts concentrated sulphuric acid (66° Beaumè).
2 parts oxalic acid of commerce.
The mass becomes gradually blue and thickens. The mass is then
washed once or twice with water, so as to remove the excess of sulphuric
and oxalic acids, taking care to dissolve as little blue as possible. After
these washings boiling water is added to the product, and it is saturated
with a slight excess of ammonia. It is allowed to cool, and is decanted.
The liquid is treated when boiling with caustic lime or baryta, so as to
decompose the ammoniacal salt previously formed and to give origin to
sulpho-conjugated combinations of lime or baryta. It then becomes
easy to separate by evaporation the calcareous combinations of the
soluble blue from the calcareous combinations of the tertiary mona-
mines. These latter not having the same solubility as the combinations
of blue. The calcareous salts of the blue are next decomposed at a
boiling temperature by carbonate or sulphate of ammonia. In this way
is obtained carbonate or sulphate of lime and the sulpho-conjugated
ammoniacal salt of the blue. The liquid is filtered and evaporated to
dryness to obtain the blue soluble in water.
To obtain potash and soda salts it is sufficient to replace the ammonia
salt by the carbonate or sulphate of potash or soda.
ن
The excess of the tertiary monamine which has not been transformed
can be again heated with oxalic and sulphuric acids to produce a further
quantity of blue coloring matter.
The mixed tertiary monamines may be readily obtained by heating

page_text: The temperature should be kept between 250° and 280° for from 12 to
15 hours, the pressure being from 10 to 12 atmospheres. After this
time decant, treat with a hot solution of caustic soda, again decant the
oily layer, and distil.
For methyldiphenylamine 24 kos. of pure methylic alcohol (wood 5
spirit) should be used.
For amyldiphenylamine the proportion of alcohol will be about 56
kos. amylic alcohol.
Having thus described the nature of my said Invention, and the
manner of performing the same, I would have it understood that I 1
claim,―
1st. The manufacture of blue coloring matter soluble in alcohol by
action of oxalic acid upon the tertiary monamines, methyldiphenylamine,
ethydiphenylamine, and amyldiphenylamine.
2nd. The manufacture of blue coloring matter directly soluble in 1
water by the simultaneous action of oxalic and sulphuric acids upon the
said tertiary monamines.
In witness whereof, I, the said Edouard George Peter Thomas,
have hereunto set my hand and seal, this Thirtieth day of
December, in the year of our Lord One thousand eight hundred 2
and seventy-four.