close

Вход

Забыли?

вход по аккаунту

?

Патент USA US2135368

код для вставки
Nov. 1, 1938.
N. H. VAGENiUS ET AL
2,135,363
METHOD OF PREPARING QUINCNE
Filed Oct. 10, 195-1,
FlG.-l
2/
20
IN VENTORS
M23 HAROL 0
By
V'Gf/V/l/é‘ Ma
120440 1[ ff/ao.
94
A TTORNEKS‘
.
Patented Nov; 1, 1938
/
'
__.
UNITED STATES‘ PATENT o..FFicEjf-,_'
2,135,368
METHOD or PREPARING QUINONE
Nels' Harold Kidd,
Vagcnius,
Warrensville,
Chicago, Ohio
Ill., and Rollo
Application October 10,
Serial No. ‘147,726 3,
7 ‘Claims. (Cl. 204-9)
Our invention relates to a method of producing
quinones, the phenol addition products thereof
and hydroquinones, and more particularly to an
improved method vof producing such compounds
by the oxidation of the phenols. In producing
quinones or hydroquinones it has heretofore been
proposed to oxidize aromatic hydrocarbons, such
as benzene, by passingtan electric current through
A further. object'of our invention is to provide
an improved process of producing quinone or the
phenol addition products thereof by the electro
chemical oxidation of phenol by'means of which.
high uniform yields of such compounds may be 5
obtained.
-
-'
Another object of'our invention is to
‘
provide
a process of producing quinone-or the phenol
anode serving to oxidize the hydrocarbon. Such
addition products’ thereof from an electrolyte
containing phenol by means of which the con
centration of the phenol is maintained substan
processes, however, are diflicult to control and
tially constant and the quinone or a phenol ad
an emulsion of benzene in an aqueous solution of
. a salt or mineral acid, the oxygen formed at the
various other ‘compounds may be formed, such as
phenols and polyphenols, or if the oxidation is
continued for a suf?cient length of time, the de
sired products are oxidized to complete disinte
gration in preference to the hydrocarbons.
Attempts have also been made to oxidize the
phenols, particularly phenol itself. Reports of
investigations show, however, that in addition to
quinone and phenoquinone other oxidation prod
1o
dition product-thereof is quickly removed from
the oxidation zone as soon ash is formed.
A further object of our invention is‘to provide 15
an improved method of preparing hydroquinone
by means of which quinone or a phenol addition
product of quinone is ?rst formed by the oxida
tion of a phenol and the hydroquinone is formed
by the‘ electrochemical reduction of the quinone
201
or a phenol addition product thereof.
Another object of our invention is to provide an
ucts are formed, such as resinous bodies, ‘poly-v
phenols, catechol, fatty acids, etc.
In view of
improved solution or electrolyte in which quinone
the side reactions which take place and the num
erous other products which are formed it has.
heretofore been impractical to produce quinone,
the phenol addition products thereof or hydro
quinone, commercially by such processes.
We have made the discovery that if phenol is
. or a phenoladdition product thereof isv insoluble
dissolved in an aqueous solution of a mineral
acid or an acidv salt in certain speci?ed propor
trochemical reduction to produce hydroquinone
and phenol, and the phenol is again utilized in
tions and the temperature maintained within a
speci?ed range, phenols may be effectively and
commercially oxidized to quinone or the phenol
the process.
an addition products thereof, depending upon the
' ‘at certain speci?ed temperatures.
T25
A still further object of our invention is to pro
vide an improved process in which a phenol addi
tion product of quinone is formed by the oxida
tion of a phenol, the product is subjected to elec
Although we do not desire to be limited in this
respect we prefer to utilize the electrochemical
method of oxidizing the vphenols to produce qui-' 35
nones or the phenol'addition products thereof,
and this method has accordingly been illustrated
in the accompanying drawing in which Fig. 1 is
a diagrammatic view of an apparatus for pro
concentration of the phenol and the temperature
at which the reaction takes place. The quinone,
or the phenol addition products thereof, may
then be reduced to hydroquinone.
While we do not desire to be limited in this
respect, our process is particularly adapted for
producing quinones or the phenol addition prod- '
ucts thereof by the electrochemical oxidation of,
the phenols. Our invention also contemplates in
its more speci?c form the production of quinone
or the phenol addition products thereof by the
oxidation of the phenols and their subsequent
reduction preferably by electrochemical means,
to form hydroquinone.
paratus for producing quinone or a phenol addi
tion product thereof, and reducing it to hydro
vide an improved process of producing quinone or
phosphoric acid. ' Solvents'which are neutral or
the phenol addition products thereof by the oxi
slightly acid may also be ‘employed, such as the
ducing quinone or the phenol addition products
40
thereof; and Fig. 2 is a similar view of an ap
quinone.
.
r
45
' In practicing our invention in accordance with I
the method illustrated in the drawing, phenol or
a homologue‘ of phenol, such as cresol or xylenol,
is dissolved in the electrolyte composed of a
dilute solution of a mineral acid which does not
It is therefore an object of our invention to pro- ' react with the phenol, such as sulphuric acid or
dation of phenols.
'
'
Another object of our invention is to provide an
effective process of preparing quinone, the phenol
alkali bisulphates. For example, sodium bisul
phate, aluminum sulphate and potassium alum 55
inum sulphate have been found suitable.
The
addition products thereof, or hydroquinone, by ' electrolyte may be present in amounts ranging
means of which such compounds may be econom-. from 5% to 20%, although we do not desire to
ically and practically produced in an economical
be limited in this respect as good results have
manner.
-.been obtained when the electrolyte-is present in 60
2,185,868
2 I
amounts as low as 1%.
As the electrolyte we
prefer to utilizean aqueous solution containing
approximately 10% of sulphuric acid. vAs illus
trated in the drawing, the electrolytelwhich con
. tains the dissolved phenol is placed in a suitable
plating tank ,2 that is capable of resisting the
solvent action of the electrolyte or any of the
oxidation products which are formed. The plat
ing tank or cell is provided with an anode 3 which
10 is preferably formed of rolled or polished lead.
,
maintain a substantially uniform concentration _.
of-the phenol in the electrolyte. As the quinone
or phenol addition product thereof is produced
and removed from the oxidation zone, additional 10
phenol should be added from the supply tank ‘I.
gauze having approximately twenty meshes per
square inch. In preparing quinone or pheno
quinone a porous diaphragm 5 is preferably inter
posed between the electrodes although this is not
process may ‘be improved by adding a small
_ seen that the concentration of the phenol in the
electrolyte is a material factor in determining
whether quinone, phenoquinone or a mixture of
these two compounds is formed.
While we have enumerated certain concentra
tions of phenol and speci?ed certain temperatures
at which quinone, phenoquinone or a mixture
thereof will crystallize from the electrolyte, we
prefer to maintain the electrolyte at a tempera
ture below 7° C. The temperature of the elec
trolyte should be above the freezing point and
below 12° C.
The most desirable temperature,
however, is slightly, above the freezing point, say
from approximately3° to 5° 0., because the qui
50 none or phenoquinone is less soluble in the elec
trolyte at low temperatures. Suitable means, such
as coils 6 through which.a cooling fluid or refrig
erant is passed, may be provided to maintain the
electrolyteat the desired temperature.
If itis desired to produce q?inhydrone', the
electrolyte is maintained at a temperature from
approximately 12° to 17° 0., preferably about 15°
C. In producing qi?nhydrone it is also essential
that the porous diaphragm be omitted.
.In plTQducing quinone,“ is essential that the
concentration of the phenol should be maintained
below 1% and in producing the addition products
of quinone, such as phenoquinone or quinhydrone,
it is essential that the concentration of the phenol
65 in the electrolyte should be maintained below 5%
and preferably below 3%,; otherwise undesirable
side reactions will take place.
During the passage of the current the quinone
or phenol addition product thereof is removed
70 from‘ the zone of oxidation, ?ltered as indicated at
8 from the mother liquor which may be returned
to the electrolyte'by means of a suitable pump 9
75
proximately one ampere per twenty-eight square
inches of surface.
5
To obtain uniform yields it is also desirable to
The cathode 4 may be formed of 'copper or bronze
essential. If it is desired to produce quinhydrone,
however, the porous diaphragm should be omit
‘ted; otherwise a precipitate containing undesir
able products will be obtained. A direct current
is then passed through the electrolyte.
The particular product which is formed will
depend upon the temperature and the concentra
tionyof the phenol and whether a porous dia
phragm is employed. If the concentration of the
25 phenol is maintained low, for example, if not
more than 1% is present and the temperature is
kept below 12° C., the product will be composed
principally of quinone, although some pheno
quinone may be produced. If the concentration
30 of the phenol is increased, a greater amount of
phenoquinone will be produced. When the con
centration of the phenol in the electrolyte is pres
ent in amounts ranging from 2% to 5% and the
temperature is_ maintained below 12° C. pheno
35 quinone will be produced. ‘It will therefore be
55
the anode may be varied within reasonable limits,
we prefer to maintain the voltage below 3.5 volts.v
The current density at the anode should be ap-~
We have also found that the e?iciency of the
amount of a catalyst. For example, approximate
ly one gram of chromium sulphate for each ?ve 15
hundred grams of electrolyte has been found suit
able.
The quinone or phenol addition product thereof
may, if desired, be reduced to hydroquinone by
any; of the usual processes. In accordance with 20
our invention the quinone or phenol addition
product thereof is ?rst formed by‘the method
which has just been described and then reduced
to hydroquinone by electrolytic reduction. The
oxidation of the phenols to quinone or the phenol 25
addition products thereof and the subsequent re
duction may be performed separately or the two
processes may be combined as illustrated in Fig. 2
of the drawing.
As illustrated in Fig. 2, the apparatus utilized in 30
producing the quinone or phenol addition product
thereof, is similar to that shown in Fig. 1 and the
parts have consequently been designated by the
same numerals. The quinone or phenol addition
product thereof which ‘is separated from the 35
mother liquor by ?ltration or other suitable means
is introduced into the electrolyte l2a of an elec
troplating cell or tank i2. The electrolyte in the
reducing step may be composed of a dilute solu
tion of sulphuric acid. It is not necessary that all 40
of the quinone or the phenol addition product
thereof should be in solution.
The cell I2 is provided with an anode 13 which
may be formed of lead and a cathode M which
may be formed of copper or bronze gauze similar 45
to that utilized in the oxidation cell. The current
is then passed through theelectrolyte utilizing ap
proximately two volts and substantially the same
current density as that employed during the'oxi
dation step. The temperature of the electrolyte 50
is maintained at approximately 60° C. and if nec
essary suitable coils I5 through which a heating
?uid may be .passed are provided for this purpose.
The efficiency of the reduction step may also be
improved by adding a suitable catalyst, such as 55
titanium sulphate or tin sulphate. Approximate
ly twp grams of the catalyst for each one hundred
grams of electrolyte has been found satisfactory.
The contents of the cell are then treated with av
small amount of charcoal and allowed to cool.
60
If quinone orpquinhydrone are ?rst prepared
they will be reduced to hydroquinone during ‘the
reduction step. If phenoquinone is-?rst prepared,
during the reducing step the quinone is reduced
to hydroquinone and the phenol floats upon the
surface of the hydroquinone and may be removed
by ‘any suitable means or method, ~such as by
skimming or decantation, or as illustrated in the
drawing the phenol may be returned to the sup
ply tank ‘I by means of a pump l6 and pipe 41.
The hydroquinone which separates in the form of .
crystals may then be removed from the cell l2 and
and pipe Hi. the crystallized product being col
separated from the mother liquor at I8 by ?ltra
lected in the receptacle ll.
tion or other suitable means and collected in the
'
'
Although the voltage and current density at
' .
receptacle I9. The mother liquor may then be ‘(I
3
2,185,868
returned to the cell I 2 by pump 20 and pipe 2|.
As previously stated, we do not desire to limit
our invention to the electrochemical method of
producing quinone or the phenol addition prod
ucts thereof. For example, the phenol in the
concentration speci?ed may be dissolved in a
dilute solution of phosphoric or sulphuric acid,
say a solution containing 1% to 20% of such acid
or preferably from 5% to 20%, and the oxidation
10 may be performed by means of suitable oxidizing
agents such as ozone, hydrogen peroxide or per
sulphuric acid.
‘
By oxidizing the phenol and maintaining the
concentration of the phenol and the tempera
15 ture within the range speci?ed during the elec
trochemical method of oxidation, either quinone
or a phenol addition product thereof, such as
phenoquinone or quinhydrone, will precipitate
and may be intermittently or continuously re
from the spirit and scope thereof. ' Our disclosure,
description and examples given herein are purely
illustrative and are not intended to be in any
sense limiting.
-
What we claim is:
1. The process of producing a quinone oxida
tion product of a phenol, at least part of which
is obtained as a precipitated solid, which com
prises passing a direct electric current through
an aqueous solution of an acidic inorganic elec 10
trolyte which is a solvent for the phenol and
which contains a substantial amount but less
than three per cent of the phenol in solution while
maintaining the electrolyte at a temperature
15
ranging from 0° C. to 17° C.
2. The process of producing a quinone oxida
tion product of a phenol, at least part of which
is obtained as a precipitated solid, which com
prises passing a direct electric currentthrough
an aqueous solution of an acidic inorganic elec 20
trolyte which is a solvent for the phenol and
which contains a substantial amount but less
than three per cent of the phenol in solution while
phenol is added to or mixed with a chilled aque- ' maintaining the electrolyte at a temperature
20 moved from the sphere of the reaction.
By utilizing the essential features of our inven
tion it is also possible to prepare the phenol ad
dition products of quinone. For example, if
ous solution of quinone or an aqueous solution
containing an electrolyte such as sulphuric or
ranging from 0° C. to 17° C., and removing'the
phosphoric acid, and the temperature is main
tained below 12° C., or preferably below 7° C.,
as they are formed. .
phenoquinone will separate. In a like manner,
by adding an aqueous solution of hydroquinone,
3. The process of producing a quinone oxida
tion product of a' phenol, at least part of which is
obtained as a precipitated solid. which comprises 30
or an aqueous solution of hydroquinone contain
passing a direct electric current through a di
ing an electrolyte, to an aqueous solution of
lute aqueous solution of sulphuric acid contain
ing a substantial amount but less than three
per cent of phenol to ,oxidize the phenol while
maintaining the electrolyte at a temperature. 35
ranging from 0° C. to 17° C.
4. The process of producing phenoquinone, at
least part of which is obtained as a precipitated
solid, which comprises passing a’ direct electric
current through an acidic inorganic electrolyte 40
quinone, or mixing the solutions together and
maintaining ‘the temperature between 12° and 17°
C., quinhydrone may be precipitated. It will
therefore be seen that the quinhydrone may be
readily converted into hydroquinone, or hydro
quinone may in turn be converted into quinhy
drone.
40
oxidation products from the zone of reaction
'
‘
.
From the foregoing speci?cation it will be ap
parent that we have provided a practical and
effective method of producing quinone or the
phenol addition products thereof byv the oxida
tion of phenols ‘which may be commercially and
economically utilized in preparing the desired
product.
It will also be seen that we have provided an
which is a solvent forv phenol and which con
tains more than one per cent and less than
three per cent of phenol in solution while mainr
taining the electrolyte at a temperature ranging
from 0° C. to 7° C.
n
5. The process of producing quinone which
comprises passing a direct electric current
economical and practical method of electrochem
ically oxidizing the phenols by means of which
through an aqueous solution of an acidic inor
quinones, phenoquinones, quinhydrones and hy
and which contains a substantial amount but
less than one per‘ cent of phenol while main
droquinones may be produced in an e?ective and
commercial manner.
It will also be apparent that we have provided
an improved process by means of which phenols
may be readily oxidized to quinone or the phenol
ganic electrolyte which is a solvent for phenol
taining the temperature of the electrolyte be
tween 0° C. and 7° C.
6. The process of producing a mixture of qui
none and phenoquinone, at least part of which 55
addition products thereof without forming large is obtained as a precipitated solid, which com
quantities of other oxidation products and that prises passing a direct electric current through
the products thus obtained may be readily and an aqueous solution of an acidic inorganic elec
trolyte which is a solvent for'phenol and which
effectively reduced to hydroquinone by electro
contains from one per cent to three per cent of
chemical means.
phenol in solution while maintaining the tem
It will also be‘ understood that we have pro
vided a method by means of which quinones or
the phenol addition, products thereof may be
effectively converted into hydroquinones by elec
tro chemical reduction.
It will be understood in the specification and
perature of the electrolyte between 0° C. and 7° C.
7. The process of producing quinhydrone, at
least part of which is obtained as a precipitated
solid, which comprises passing a direct electric
current between electrodes placed inan acidic
' claims that the term “quinone oxidation product
inorganic electrolyte which is a solvent for
of a phenol” is intended to include not only
quinone itself but also the phenol addition prod
phenol and which contains phenol in substantial
amounts but less than three per cent while
maintaining the temperature of the electrolyte
ucts thereof.
_
To those skilled in the“ art many modi?cations
and widely differing embodiments of our inven
tion will suggest themselves without departing
between 12° C. and 17° C.
NE'LS HAROLD VAGENIUS.‘
RDLLO J. EDD.
Документ
Категория
Без категории
Просмотров
0
Размер файла
541 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа