U.S. patent application number 10/115235 was filed with the patent office on 2002-08-08 for process for the preparation of vinylene carbonate, polyvinylene carbonate and the use thereof and the preparation of a lithium ion battery comprising said vinylene carbonate.
This patent application is currently assigned to Merck Patent GmbH. Invention is credited to Becker, Sylvia, Neuschutz, Mark, Seifert, Bernhard.
Application Number | 20020107407 10/115235 |
Document ID | / |
Family ID | 7929786 |
Filed Date | 2002-08-08 |
United States Patent
Application |
20020107407 |
Kind Code |
A1 |
Seifert, Bernhard ; et
al. |
August 8, 2002 |
Process for the preparation of vinylene carbonate, polyvinylene
carbonate and the use thereof and the preparation of a lithium ion
battery comprising said vinylene carbonate
Abstract
The invention relates to a process for the preparation of
vinylene carbonate of the formula (I) 1 by reacting a
monohaloethylene carbonate of the formula (II) 2 in which X is a
halogen atom, with a dehydrohalogenating agent at elevated
temperature in the presence of an organic solvent, characterized in
that the organic solvent employed is ethylene carbonate. The
process according to the invention enables vinylene carbonate to be
prepared in a simple manner and in high yield. The vinylene
carbonate prepared in accordance with the invention can be used for
various applications.
Inventors: |
Seifert, Bernhard;
(Ober-Ramstadt, DE) ; Becker, Sylvia;
(Seeheim-Jugenheim, DE) ; Neuschutz, Mark;
(Darmstadt, DE) |
Correspondence
Address: |
MILLEN, WHITE, ZELANO & BRANIGAN, P.C.
2200 CLARENDON BLVD.
SUITE 1400
ARLINGTON
VA
22201
US
|
Assignee: |
Merck Patent GmbH
Darmstadt
DE
64293
|
Family ID: |
7929786 |
Appl. No.: |
10/115235 |
Filed: |
April 4, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10115235 |
Apr 4, 2002 |
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09715048 |
Nov 20, 2000 |
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6395908 |
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Current U.S.
Class: |
549/230 |
Current CPC
Class: |
H01M 10/0525 20130101;
C07D 317/40 20130101; Y02E 60/10 20130101; H01M 10/0567
20130101 |
Class at
Publication: |
549/230 |
International
Class: |
C07D 317/08 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 19, 1999 |
DE |
19955944.9 |
Claims
1. A process for the preparation of vinylene carbonate of formula
(I) 5comprising reacting a monohaloethylene carbonate of formula
(II) 6in which X is a halogen atom, with a dehydrohalogenating
agent at elevated temperature in the presence of an organic solvent
comprising ethylene carbonate.
2. The process according to claim 1, carried out at a temperature
of 40-80.degree. C.
3. The process according to claim 1, carried out at a temperature
of 60.degree. C.
4. The process according to claim 1, carried out for 1 to 4
hours.
5. The process according to claim 1, carried out for 2 hours.
6. The process according to claim 1, wherein the
dehydrohalogenating agent comprises an alkali metal solution, an
amine, an alkylamide or a heterocyclic nitrogen compound.
7. The process according to claim 1, wherein the
dehydrohalogenating agent comprises a trialkylamine.
8. The process according to claim 1, wherein the
dehydrohalogenating agent comprises triethylamine.
9. The process according to claim 1, wherein the monohaloethylene
carbonate comprises monoethylene carbonate.
10. The process according to claim 1, wherein the reaction is
carried out under an inert gas atmosphere.
11. The process according to claim 1, further comprising separating
vinylene carbonate by distillation.
12. The process according to claim 1, further comprising separating
vinylene carbonate by vacuum distillation in a thin-film
evaporator.
13. A process according to claim 1, further comprising introducing
into a cell an electrolyte containing said vinylene carbonate, to
form a lithium ion battery.
14. A process according to claim 1, further comprising polymerizing
said vinylene carbonate to produce polyvinylene carbonate.
Description
SUMMARY OF THE INVENTION
[0001] The present invention relates to a process for the
preparation of vinylene carbonate, and to the use of the vinylene
carbonate prepared, for example as an additive for lithium ion
batteries, as a component of surface coatings or as a monomer for
the preparation of polyvinylene carbonate.
[0002] J. Am. Chem. Soc., 77, 3789 -3793 (1955) discloses a process
for the preparation of vinylene carbonate in which, in a first
synthesis step, monochloroethylene carbonate is prepared by
chlorination of ethylene carbonate. In a second step, a solution of
monochloroethylene carbonate in ether is reacted with triethylamine
overnight underref lux to give vinylene carbonate by elimination of
hydrogen chloride. After removal of the ether and distillation,
crude vinylene carbonate is obtained in a yield of 59%, and is
purified by further rectification. Disadvantageous features of this
process are thus the long reaction times, the relatively complex
work-up of the reaction product for removal of undesired
components, such as solvents, and the relatively low yield of the
target product.
[0003] The present invention provides a process which enables, in a
simple and economical manner, the preparation of vinylene carbonate
in high yields.
[0004] The invention thus relates to a process for the preparation
of vinylene carbonate of the formula (I) 3
[0005] by reacting a monohaloethylene carbonate of the formula (II)
4
[0006] in which X is a halogen atom(e.g., Br, Cl, F, I), with a
dehydrohalogenating agent, preferably at elevated temperature in
the presence of an organic solvent, which is characterized in that
the organic solvent employed is ethylene carbonate.
[0007] The ether used in the conventional process is replaced in
the process according to the invention by ethylene carbonate as
solvent in the dehydrohalogenation reaction. This reduces the
number of interfering compounds present in the reaction mixture and
thus simplifies work-up of the reaction mixture. Furthermore,
significantly higher yields are achieved in the process according
to the invention compared with the known process. For certain
applications, for example as solvent for non-aqueous electrolytes
in lithium ion batteries, it is not necessary to separate off the
ethylene carbonate present in the reaction mixture, but instead a
vinylene carbonate/ethylene carbonate mixture of this type is
virtually desired for this use.
[0008] Experiments have shown that vinylene carbonate is highly
temperature-sensitive and can decompose within hours at
temperatures above 60.degree. C. and even within minutes at above
80.degree. C. However, elimination reactions generally proceed in
higher yields at higher temperatures. It has been shown in
accordance with the invention that the dehydrohalogenation reaction
here can favorably be carried out at temperatures in the range 40
-80.degree. C., preferably at about 60.degree. C., although lower
(e.g., room temperature) or higher temperatures are possible. In
this case, the reaction can be completed within a period of 1-4
hours, preferably within about 2 hours. Under such reaction
conditions, the yield of crude vinylene carbonate is usually
greater than 80%. Preferably, a ratio of monohaloethylene
carbonate: dehydrohalogenating agent from 1:1 to 1:2, more
preferably 1:1.5, is used. The monohaloethylene carbonate is
preferably 99.5% pure, with <0.01% glycol, e.g., ethylene
glycol.
[0009] Conventional dehydrohalogenating agents, for example alkali
metal hydroxide solutions, amines, alkylamides or heterocyclic
nitrogen compounds, can be employed for the process according to
the invention. Preference is given to trialkylamines, particularly
preferably triethylamine. Preferably the dehydrohalogenation agent
is 99% pure.
[0010] The process according to invention proceeds particularly
favorably in the presence of monochloroethylene carbonate as
monohaloethylene carbonate of the above formula (II).
[0011] It is furthermore particularly advantageous to use an inert
gas atmosphere for the reaction according to the invention in order
to avoid decomposition reactions. Examples of suitable protective
gases are nitrogen and noble gases, such as argon. The use of a
stabilizer which is usually employed for the vinylene carbonate
obtained as reaction product is thus unnecessary.
[0012] For a complete and uniform reaction, it is furthermore
advantageous to ensure good mixing of the reaction components.
[0013] The monohaloethylene carbonates employed as starting
compounds according to the invention are known compounds which can
be prepared, for example, by photochemical halogenation or by
azoisobutyronitrile-(AIBN-)i- nitiated halogenation of ethylene
carbonate using, for example, sulfuryl chloride. Residual amounts
of AIBN or sulfuryl chloride in the monohaloethylene carbonate are
permissible here. Residual amounts of sulfuryl chloride present can
be eliminated in the process according to the invention, for
example by using a corresponding excess of dehydrohalogenating
agent, such as triethylamine.
[0014] Whereas in the conventional process the work-up of the crude
vinylene carbonate obtained is carried out by simple distillation,
it has been found in accordance with the invention that undesired
reductions in yield can occur in this case. Preferably, therefore,
a work-up process which ensures that the vinylene carbonate remains
at the corresponding evaporation temperature for the shortest
possible time is employed in accordance with the invention. This is
achieved, for example, by means of vacuum distillation in a
thin-film evaporator at bath temperatures of about 100.degree. C.
and a pressure of about 5 mbar. This enables vinylene carbonate to
be obtained directly from the dehydro-halogenation reaction product
as a colorless product in a yield of about at least 75%.
[0015] The vinylene carbonate prepared in the process according to
the invention can be employed for various applications, for example
as an additive for lithium ion batteries, e.g. as solvent for
non-aqueous electrolytes, (U.S. Pat. Nos. 5,626,981, 5,712,059 and
5,352,548) as a component of surface coatings or as a monomer for
the preparation of polyvinylene carbonate. In the latter
polymerization, high-molecular-weight, colorless polymers can be
obtained which give water-soluble polymers through a subsequent
hydrolysis reaction.
[0016] Without further elaboration, it is believed that one skilled
in the art can, using the preceding description, utilize the
present invention to its fullest extent. The following preferred
specific embodiments are, therefore, to be construed as merely
illustrative, and not limitative of the remainder of the disclosure
in any way whatsoever.
[0017] In the foregoing and in the following examples, all
temperatures are set forth uncorrected in degrees Celsius; and,
unless otherwise indicated, all parts and percentages are by
weight.
[0018] The entire disclosure of all applications, patents and
publications, cited above, and of corresponding German application
No. DE 199 55 944.9, filed Nov. 19, 1999 is hereby incorporated by
reference.
EXAMPLES
Example 1
[0019] A 250 ml twin-jacket, four-neck apparatus equipped with
precision glass stirrer, stirrer motor, coil condenser, dropping
funnel and thermometer in the liquid phase is flushed with argon.
0.420 mol of chloroethylene carbonate and 84 ml of ethylene
carbonate (anhydrous) are then introduced with continued flushing
with argon. The internal temperature is raised to 57.6.degree. C.
by means of a heating bath. 0.630 mol of triethylamine are then
added dropwise via a dropping funnel over the course of 25 minutes
with stirring, during which the internal temperature is kept at
between 56 and 590C. When the addition of the triethylamine is
complete, the reaction mixture is stirred at about 60.degree. C.
for 1 hour. Excess triethylamine is then distilled off on a rotary
evaporator at a bath temperature of 40.degree. C. and a pressure of
150 mbar. The amount of vinylene carbonate present in the crude
vinylene carbonate mixture is 77.2% of theory.
Comparative Example 1
[0020] Vinylene carbonate is prepared by the process described in
J. Am. Chem. Soc. 77, 3789 -3793 (1955). To this end, the apparatus
described in Example 1 is flushed with argon. 0.280 mol of
chloroethylene carbonate and 33.4 ml of tert-butyl methyl ether
(ultra-pure) are then introduced into the apparatus while flushing
with argon, and the mixture is warmed to 37.8.degree. C. by means
of a heating bath. 0.350 mol of triethylamine are then added
dropwise via a dropping funnel over the course of 50 minutes with
stirring, during which the internal temperature is kept at between
37 and 40.degree. C.. The reaction mixture is then kept at about
40.degree. C. for 50 minutes with stirring. The amount of vinylene
carbonate present in the crude vinylene carbonate mixture is only
26.6% of theory.
Example 2
[0021] The crude vinylene carbonate mixture obtained in Example 1
is worked up by vacuum distillation in a thin-film evaporator
(internal diameter: 40 mm, rotor length: 25 cm). The bath
temperature is about 100.degree. C. and the pressure is about 5
mbar. At a feed rate of about 3 ml/min, a clear, slightly
yellowish, oil-like distillate is obtained after about 70 minutes.
The yield of purified vinylene carbonate here is 73.3%.
[0022] The preceding examples can be repeated with similar success
by substituting the generically or specifically described reactants
and/or operating conditions of this invention for those used in the
preceding examples.
[0023] From the foregoing description, one skilled in the art can
easily ascertain the essential characteristics of this invention
and, without departing from the spirit and scope thereof, can make
various changes and modifications of the invention to adapt it to
various usages and conditions.
* * * * *