IMPROVEMENTS IN THE MANUFACTURE OF BLUE COLORING MATTER
Year: 1866

page_text: LETTERS PATENT to Charles Adam Girard, of 66, Rue des Ecoles, Paris,
in the Empire of France, Chemist, for the Invention of "IMPROVEMENTS
IN THE MANUFACTURE OF BLUE COLORING MATTER."-Partly a communi-
cation from abroad by George de Laire, residing at Rue de Sévres, Paris,
Chemist.
Sealed the 9th April 1867, and dated the 17th October 1866.
PROVISIONAL SPECIFICATION left by the said Charles Adam Girard at
⚫ the Office of the Commissioners of Patents, with his Petition, on the
17th October 1866.
I, CHARLES ADAM GIRARD, of 66, Rue des Ecoles, Paris, in the Empire of
France, Chemist, do hereby. declare the nature of the said Invention for:
"IMPROVEMENTS IN THE MANUFACTURE OF BLUE COLORING MATTER," to be as
follows:-
.5
- This Invention has for its object improvements in the manufacture of blue
coloring matter. For this purpose I take diphenylamine, such as is prepared:
from commercial aniline or a mixture of diphenylamine with its homologues,.
or one of them, and I treat it with the sesquichloride of carbon in the.
proportion, say, of two parts by weight of commercial diphenylamine to three:
parts of chloride of carbon. I heat the mixture to a temperature of say:

page_text: from 140° to 180° centigrade for several hours, by which time the mass will
have a bronzed aspect and will be brittle on cooling; it is powdered, and
the untransformed sesquichloride of carbon and commercial diphenylamine
is dissolved out by a solvent such as benzole or petroleum spirit. The color
is thus obtained in a state fit for use, or it may be further purified by dis-
solving it in alcohol or methylated spirit, and precipitating it with an excess
of hydrochloric acid. In place of employing the sesquichloride of carbon,
oxalic acid may be used in a similar manner. Arsenic acid and the perchloride
of naphtaline will also yield a blue color with diphenylamine and its homo-
logues by a process similar to that above described. The oxalic acid may be
mixed with sulphuric acid, or it may be used alone, but in this case the heat
employed should be somewhat lower.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filod
by the said, Charles Adam Girard in the Great Seal Patent Office on
the 16th April 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
ADAM GIRARD, of 66, Ruc des Ecoles, Paris, in the Empire of France,
Chemist, send greeting..
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventeenth day of October, in the year of our
Lord One thousand eight hundred and sixty-six, in the thirtieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Charles Adam Girard, Her special licence that I, the said Charles
Adam Girard, my executors, administrators, and assigns, or such others as I,
the said Charles Adam Girard, 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," the result
partly of my own Invention and partly of communications made to me abroad
by George de Laire, a person resident- at Rue de Sevres, Paris, Chemist,
upon the condition (amongst others) that I, the said Charles Adam Girard,
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.

page_text: 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 Charles Adam Girard, do hereby declare
the nature of the said Invention, and in what manner the same is to bo
performed, to be particularly described and ascertained in and by the follow-
ing statement thereof, that is to say:-
.
. In order to obtain blue dye I introduce into a distilling apparatus (the
retort and receiver may be of enamelled cast iron) 2 parts of commercial
diphenylamine and 3 parts of sesquichloride of carbon, and I heat the mixture,
taking care to maintain- the temperature between 170° and 190° centigrade:
The blue color is rapidly developed, and in 5 or 6 hours the mass assumes
a bronzed aspect and becomes brittle on cooling. During the reaction
hydrochloric acid is evolved and protochloride of carbon distils over. Tho
quantity of protochloride of carbon collected is proportionate to the
diphenylamine transformed into coloring matter; a small quantity of sesqui-
chloride of carbon is also volatilized and condenses in the neck of the retort.
The retort and receiver should be of enamelled cast iron, and the retort should'
be furnished with an agitator worked by a rod or axis passing into the retort
through a stuffing box at the top. The melt with the bronzed aspect is
powdered and treated until complete exhaustion in a displacement apparatus
with benzole or ether at a gentle heat; in this apparatus the warm solvent
filters through the powdered melt and is afterwards distilled, the vapour is
condensed and returned on to the melt, and so on continually. The untrans-
formed sesquichloride of carbon and commercial diphenylamine are dissolved
as well as a small quantity of bluish violet; the greater part and the best
part of the blue remains undissolved; the blue is then collected and dried,
and may after being dissolved in alcohol or methylated spirit be at once
employed in dyeing or printing; but if it be desired to purify it further it
may be dissolved in boiling alcohol; filtered and precipitated from the filtered
solution by hydrochloric acid. The proportions of alcohol and hydrochloric
acid which I prefer are about 2 volumes of acid for one volume of alcohol;
after one or two successive solutions and precipitations the blue is almost
chemically purc. The acid alcoholic liquors contain in solution a mixture of
blue, and principally of violet and brown coloring matters. I have observed
that pure ditolylamine yields under the same conditions a brown coloring
matter; pure diphenylamine yields a blackish-violet blue; and phenyltolylamine
a bluish violet or violet blue; but a mixture of diphenylamine and ditolylamine
and of diphenylamine and phenyltolylamino in any proportions yield a blue.

page_text: I would remark, however, that some proportions are better than others, and I
find that 2 parts of diphenylamine and 1 part of ditolylamine are good pro-
portions; commercial diphenylamino should therefore contain such proportions
of diphenylamine and ditolylamine as nearly as practicable. Oxalic acid may
also be employed for the transformation of commercial diphenylamino into
blue dye, but the yield is less. The proportions which I prefer are about
equal parts of commercial diphenylamine and oxalic acid. The mixture is
heated to a temperature of 110 to 120° centigrade for from 3 to 5 hours;
it is very important not to raise the heat beyond this temperature, as the dyo
would then be destroyed. When the mixture has reached its maximum of
coloring power it is allowed to cool, and boiling water is added to remove the
excess of oxalic acid; it is then dried and treated with benzole, which
dissolves the untransformed diphenylamine. One treatment with alcohol and
precipitation by hydrochloric acid as described above yields the dye in a state
of purity.
What I claim is, the treating diphenylamine and the other similar sub-
stances herein mentioned with sesquichloride of carbon so as to obtain blue
coloring matter, as herein-before described.
I also claim the treating diphenylamine and the other similar substances
herein mentioned with oxalic acid so as to obtain blue coloring matter, as
herein-before described.
In witness whereof, I, the said Charles Adam Girard, have hereunto
set my hand and seal, this Thirteenth day of April, in the year of
our Lord One thousand eight hundred and sixty-seven.