Improvements in the Purification of Anthracene.
Year: 1894

page_text: Date of Application, 20th Apr., 1894
Complete Specification Left, 18th Jan., 1895-Accepted, 23rd Feb., 1895
[Communicated from abroad by THE FARBENFABRIKEN, vormals FRIEDRICH
BAYER & Co., of Elberfeld, Germany.]
Improvements in the Purification of Anthracene.
I, HENRY EDWARD NEWTON of The Office for Patents, 6 Bream's Buildings,
Chancery Lane, in the County of London, Patent Agent, do hereby declare the
nature of this invention to be as follows:-
This invention relates to a new method of purifying anthracene.
It is known that the purification of raw anthracene has been effected hitherto by
means of hydro-carbons or naphtha, or with the aid of aromatic bases, such as bases
of the aniline or pyridine or quinoline series (see the Specification of the English
Letters Patent No. 5785 of 1887), or by means of liquid sulphur dioxide, as
described in the Specification of the English Letters Patent No. 5539, dated
21st March 1892.
My foreign correspondents have now found that, in order to purify raw or
technical anthracene, the ketones of the fatty series, especially acetone and the
homologues thereof, which are advantageously employed for cheapness' sake in the
form of so called "raw acetone," or "acetone oils," can be used, as, according to
the researches of my foreign correspondents, these agents possess in a high degree
the property of dissolving the associated impurities in crude anthracene, whilst the
anthracene itself is almost insoluble therein.
In order to illustrate one method of carrying out this new process, the following
example is given. The parts are by weight.
EXAMPLE.
500 parts of raw anthracene are mixed (while being stirred) with 750 parts of,
acetone in a closed cylinder, with steam jacket and stirring apparatus. The mass
is heated to 60 degrees Centigrade, and kept at this temperature during one hour.
After this time, the mass is allowed to cool. The anthracene is filtered off and
washed with 375 parts of fresh acetone. The latter acetone, after being used for
washing, is separated, and then employed for purifying a fresh quantity of
anthracene. The first obtained mother-liquors are distilled, in order to recover the
acetone. The anthracene remaining on the filter is pressed and dried in the usual
manner.
When, for instance, anthracene containing from 34 to 35 per cent. is used, a
purified anthracene containing 82 per cent. is obtained with the greatest readiness,
whilst the residue obtained after distilling off the mother liquor, contains but a very
slight percentage of anthracene.
In the carrying out practically of this new process, my foreign correspondents do
not limit themselves to the directions given in the above example, as these can be
varied. For instance, the quantity of the acetone used can vary within certain
limits, according to the percentage of the raw anthracene. The so called "acetone
oils or raw acetone, or the higher homologues of acetone, such as methylethyl-
ketone, can be used with the samne result, in place of acetone employed as mentioned
in the above example. The temperature can also be higher or lower, and.
"
077

page_text: accordingly the duration of the process may be shorter or longer. The process can
be carried on in closed or open vessels; but, as a matter of course, it is more
advantageous to use closed vessels, thereby preventing the loss of the agents used
for effecting the purification.
Such or similar modifications do not alter the nature of the present invention,
which relates to the purification of anthracene, or raw anthracene, by means of
ketones of the fatty series, or mixtures of such ketones, for instance, with the aid
of acetone, acetone oil, methylethylketone, or the like.
Dated this 20th day of Anril 1894
NEWTON & SON,
Agents for the Applicant.
Improvements in the Purification of Anthracene.
HENRY EDWARD NEWTON of The Office for Patents, 6 Bream's Buildings,
Chancery Lane in the County of London, Patent Agent, 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 a new method of purifying anthracene.
It is known that the purification of raw anthracene has been hitherto effected by
means of hydrocarbons or naphtha, or with the aid of aromatic bases, such as bases
of the aniline or pyridine or quinoline series (see the Specification of the English
Letters Patent No. 5785 of 1887), or by means of liquid sulphur dioxide, as
described in the Specification of the English Letters Patent No. 5539, dated
21st March 1892.
My foreign correspondents have now found, that the purification of raw or
technical anthracene may be effected by means of ketones of the fatty series,
especially acetone and the homologues thereof, which are advantageously used, for
the sake of cheapness, in the form of so-called "raw acetone," or "acetone oils,'
these agents possessing in a high degree the property of dissolving the associated
impurities in crude anthracene, whilst the anthracene itself is almost insoluble
therein.
In order to illustrate one method of carrying out this new process, the following
example is given. The parts are by weight.
EXAMPLE.
500 parts of raw anthracene are mixed, by stirring, with 750 parts of acetone in
a closed cylinder provided with a steam jacket and stirring apparatus. The mixture
is heated to 60 degrees Centigrade, and kept at this temperature during about one
hour, after which time the mass is allowed to cool. The anthracene is then filtered off
and washed with 375 parts of fresh acetone. The acetone thus used for washing
is separated and made use of in purifying a fresh quantity of anthracene. The first
mother liquors are distilled, in order to recover the acetone. The anthracene
remaining on the filter is pressed and dried in the usual manner.
When, for instance, a crude material containing from 34 to 35 per cent. of
anthracene is used, a purified anthracene containing 82 per cent. is obtained with the
greatest readiness, the residue obtained on distilling off the mother liquor containing
but a very slight percentage of anthracene.
In carrying out this new process practically, my foreign correspondents do not
limit themselves to the directions given in the above example, as these can be varied.
For instance, the quantity of acetone used can be varied within certain limits,
according to the percentage of anthracene in the raw material. So-called "acetone

page_text: oils," or «
raw acetone," or the higher homologues of acetone, such as methylethyl-
ketone, can be equally well used instead of acetone. The temperature can also be
higher or lower, and, accordingly, the duration of the process may be shorter or longer.
The process can be carried on in closed or open vessels, but, as a matter of course,
it is more advantageous to use closed vessels, thereby preventing the loss of the
agents used for effecting the purification.
Such or similar modifications do not alter the nature of the present invention,
which relates to the purification of anthracene, or raw anthracene, by means of
ketones of the fatty series, or mixtures of such ketones, for instance, with the aid
of acetone, acetone oil, methylethylketone, or the like.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me
from abroad, I declare that what I claim is :-
1. The use of ketones of the fatty series, such as acetone, the homologues thereof,
raw acetone, ocetone oils, or the like, for purifying anthracene.
or
2. The process for purifying anthracene, which consists in treating raw
technical anthracene with fatty ketones, such as acetone, its homologues, or raw
acetone, or acetone oils or the like, and separating the undissolved purified
anthracene from the associated foreign matters dissolved in the ketone or the like
means used for purifying.
Dated this 17th day of January 1895.
NEWTON & SON,
Agents for the Applicant