JPH06263725A - Purification of n-methyl-2-pyrrolidone - Google Patents
Purification of n-methyl-2-pyrrolidoneInfo
- Publication number
- JPH06263725A JPH06263725A JP5228193A JP5228193A JPH06263725A JP H06263725 A JPH06263725 A JP H06263725A JP 5228193 A JP5228193 A JP 5228193A JP 5228193 A JP5228193 A JP 5228193A JP H06263725 A JPH06263725 A JP H06263725A
- Authority
- JP
- Japan
- Prior art keywords
- methyl
- pyrrolidone
- column
- temperature
- distillation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Pyrrole Compounds (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明はＮ−メチル−２−ピロリ
ドンの精製方法に関するものであり、特に経時着色の著
るしく少ないＮ−メチル−２−ピロリドンを取得する方
法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for purifying N-methyl-2-pyrrolidone, and more particularly to a method for obtaining N-methyl-2-pyrrolidone which is markedly less colored over time.
【０００２】[0002]
【従来の技術】Ｎ−メチル−２−ピロリドンは無毒性で
耐熱性に富み、かつ化学的にも安定なので、溶剤として
広く利用されている。また、最近ではハロゲン化炭化水
素に代る洗浄剤としても注目されている。Ｎ−メチル−
２−ピロリドンは工業的にはγ−ブチロラクトンとメチ
ルアミンとの反応によって製造されている。この反応で
は水が生成するが、反応系にさらに水を添加すると好ま
しいことが知られている。また、γ−ブチロラクトンと
Ｎ−メチル−２−ピロリドンとの蒸留分離は極めて困難
なので、メチルアミンを過剰に用いてγ−ブチロラクト
ンの反応を完結させるのが好ましい。2. Description of the Related Art N-methyl-2-pyrrolidone is widely used as a solvent because it is non-toxic, highly heat resistant, and chemically stable. Further, recently, it has been attracting attention as a cleaning agent that replaces halogenated hydrocarbons. N-methyl-
2-Pyrrolidone is industrially produced by the reaction of γ-butyrolactone and methylamine. Although water is produced in this reaction, it is known that it is preferable to further add water to the reaction system. Further, since it is extremely difficult to separate γ-butyrolactone and N-methyl-2-pyrrolidone by distillation, it is preferable to use methylamine in excess to complete the reaction of γ-butyrolactone.
【０００３】[0003]
【発明が解決しようとする課題】Ｎ−メチル−２−ピロ
リドンの製造上の問題点の一つは、製品のＮ−メチル−
２−ピロリドンが経時着色し易いことである。Ｎ−メチ
ル−２−ピロリドンの精製法としては、水を添加して蒸
留する方法（特公昭４６−３２２６３）や酸化剤で処理
する方法（特公昭４７−２２２２５）などが知られてい
るが、経時着色の問題を解決するに至っていない。One of the problems in the production of N-methyl-2-pyrrolidone is N-methyl-
That is, 2-pyrrolidone is easily colored over time. As a method for purifying N-methyl-2-pyrrolidone, a method of adding water and distilling (Japanese Patent Publication No. 46-32263), a method of treating with an oxidizing agent (Japanese Patent Publication No. 47-22225), etc. are known. The problem of coloring over time has not been solved.
【０００４】[0004]
【課題を解決するための手段】本発明によれば、Ｎ−メ
チル−２−ピロリドンを水の共存下に下記条件下で熱処
理したのち蒸留することにより、経時着色の著るしく少
ないＮ−メチル−２−ピロリドンを取得することができ
る。 Ｔ＞１５０−７ｌｎ（θｔ） （Ｔは温度（℃）、θｔは時間（ｈｒ）を示す） 本発明について詳細に説明するに、本発明はγ−ブチロ
ラクトンとメチルアミンとからＮ−メチル−２−ピロリ
ドンを製造する工程に組込んで実施するのが有利である
が、保管中に着色したＮ−メチル−２−ピロリドンや各
種の用途に供して汚染されたＮ−メチル−２−ピロリド
ンを蒸留精製する工程に組込んで実施することもでき
る。According to the present invention, N-methyl-2-pyrrolidone is heat-treated in the presence of water under the following conditions and then distilled to obtain N-methyl which is markedly less colored over time. -2-Pyrrolidone can be obtained. T> 150-7ln (θt) (T indicates temperature (° C.), θt indicates time (hr)) The present invention will be described in detail. The present invention is based on γ-butyrolactone and methylamine. -It is advantageous to implement it by incorporating it into the process for producing pyrrolidone, but distillation of colored N-methyl-2-pyrrolidone during storage and N-methyl-2-pyrrolidone contaminated during various uses are distilled. It can also be carried out by incorporating it in the step of purifying.
【０００５】γ−ブチロラクトンとメチルアミンとから
Ｎ−メチル−２−ピロリドンを製造するには、γ−ブチ
ロラクトンとこれに対して過剰量、好ましくは１．１〜
１．５倍モルのメチルアミンとを反応系に供給し、２０
０〜３００℃の温度かつ５ｋｇ／ｃｍ2 Ｇ以上の圧力、
好ましくは２０〜６０ｋｇ／ｃｍ2 Ｇの圧力下に反応さ
せる。この際、反応系にγ−ブチロラクトンに対して１
〜６倍モルの水を供給するのが好ましい。反応はγ−ブ
チロラクトンからＮ−メチル−２−ピロリドンへの転換
が事実上完結するまで、すなわち未反応のγ−ブチロラ
クトンや反応中間体と目されるγ−オキシ酪酸アミド類
の量が最少量となるまで行なうのが好ましい。In order to produce N-methyl-2-pyrrolidone from γ-butyrolactone and methylamine, γ-butyrolactone and an excess amount thereof, preferably 1.1 to
Supply 1.5 times mole of methylamine to the reaction system,
A temperature of 0 to 300 ° C. and a pressure of 5 kg / cm 2 G or more,
The reaction is preferably carried out under a pressure of 20 to 60 kg / cm 2 G. At this time, 1 was added to γ-butyrolactone in the reaction system.
It is preferred to supply ~ 6 times the molar amount of water. The reaction is carried out until the conversion of γ-butyrolactone to N-methyl-2-pyrrolidone is practically completed, that is, the amount of unreacted γ-butyrolactone and γ-oxybutyric acid amides, which are considered as reaction intermediates, is the minimum. It is preferable to carry out until.
【０００６】反応液は脱アミン塔に供給し、蒸留して塔
頂からメチルアミン並びに軽沸成分及び水の一部を留出
させ、塔底からは水を含むＮ−メチル−２−ピロリドン
を抜出す。本発明の好適な態様では、この水を含むＮ−
メチル−２−ピロリドンを脱水蒸留塔に供給し、蒸留し
て塔頂から水と軽沸成分を留出させ、塔底からＮ−メチ
ル−２−ピロリドンを抜出して次の精留塔に供給する。
脱水蒸留塔に供給するＮ−メチル−２−ピロリドンの含
水率は通常１０〜２０（重量）％であり、１３〜１７
（重量）％が好ましい。脱水蒸留塔は、Ｎ−メチル−２
−ピロリドンが塔内において Ｔ＞１５０−７ｌｎ（θｔ） （Ｔは温度（℃）であり、θｔは時間（ｈｒ）である）
なる温度−時間関係を満足するように操作する。通常は
塔底温度を１５０〜２５０℃の範囲に維持して蒸留を行
なう。塔底温度を１８０°〜２３０℃とし、且つ 、 Ｔ＞１８０−７ｌｎ（θｔ） なる温度−時間関係を満足するように蒸留を行なうのが
最も好ましい。The reaction solution is supplied to a deamine column and distilled to distill off methylamine, a light-boiling component and part of water from the top of the column, and N-methyl-2-pyrrolidone containing water from the bottom of the column. Pull out. In a preferred embodiment of the present invention, the water-containing N-
Methyl-2-pyrrolidone is supplied to a dehydration distillation column, distilled to distill water and light-boiling components from the top of the column, N-methyl-2-pyrrolidone is extracted from the bottom of the column and supplied to the next rectification column. .
The water content of N-methyl-2-pyrrolidone supplied to the dehydration distillation column is usually 10 to 20 (weight)%, and 13 to 17
(Wt)% is preferred. The dehydration distillation column is N-methyl-2
-Pyrrolidone in the tower T> 150-7ln (θt) (T is temperature (° C), θt is time (hr))
The temperature-time relationship is satisfied. Usually, distillation is carried out while maintaining the bottom temperature in the range of 150 to 250 ° C. Most preferably, the column bottom temperature is 180 ° to 230 ° C., and distillation is performed so as to satisfy the temperature-time relationship of T> 180-7ln (θt).
【０００７】精留塔では脱水蒸留塔で熱処理を経たＮ−
メチル−２−ピロリドンを精留して、塔頂から精製され
たＮ−メチル−２−ピロリドンを留出させ、塔底から高
沸成分を抜出す。脱水蒸留塔で水その他の軽沸成分を完
全に除去しきれない場合には、Ｎ−メチル−２−ピロリ
ドンは塔頂と原料供給位置との間から側流として抜出す
ようにしてもよい。高沸成分中にはＮ−メチル−２−ピ
ロリドンが含有されているので、所望により減圧蒸留し
てＮ−メチル−２−ピロリドンを回収することができ
る。In the rectification column, N- which has undergone heat treatment in the dehydration distillation column
Methyl-2-pyrrolidone is rectified to distill purified N-methyl-2-pyrrolidone from the top of the column, and high boiling components are extracted from the bottom of the column. When water and other light-boiling components cannot be completely removed by the dehydration distillation column, N-methyl-2-pyrrolidone may be withdrawn as a sidestream from between the top of the column and the raw material supply position. Since N-methyl-2-pyrrolidone is contained in the high boiling component, N-methyl-2-pyrrolidone can be recovered by distillation under reduced pressure if desired.
【０００８】精留塔は通常、塔底温度８０〜２２０℃、
塔頂圧力１０〜７６０ｍｍＨｇで操作する。好ましくは
１００ｍｍＨｇ以下の減圧下に操作して、Ｎ−メチル−
２−ピロリドンが高温にさらされないようにする。保留
中に着色したＮ−メチル−２−ピロリドンや各種の用途
に供して汚染されたＮ−メチル−２−ピロリドンを本発
明方法により精製する場合には、上述の如き連続蒸留と
は異なり回分蒸留方式を採用するのが好ましい。すなわ
ち回分蒸留塔に所定の水分含有率に調整したＮ−メチル
−２−ピロリドンを仕込み、塔底温度を１５０〜２５０
℃に維持して Ｔ＞１５０−７ｌｎ（θｔ） なる条件を満足するように全還流を行なったのち蒸留す
る。好ましくは１８０〜２３０℃の塔底温度に維持しＴ
＞１８０−７ｌｎ（θｔ）なる条件下に全還流を行な
う。蒸留初期には軽沸成分や水が留出し、これらが留出
しつくすとＮ−メチル−２−ピロリドンが留出し始め
る。水とＮ−メチル−２−ピロリドンとでは沸点が１０
０℃以上も異なるので、水の留出が終了したら減圧にし
てＮ−メチル−２−ピロリドンの留出を促出するのが好
ましい。The rectification column usually has a bottom temperature of 80 to 220 ° C.,
Operate at a top pressure of 10 to 760 mmHg. It is preferable to operate under reduced pressure of 100 mmHg or less to obtain N-methyl-
Avoid exposing the 2-pyrrolidone to high temperatures. When purifying N-methyl-2-pyrrolidone colored during holding and N-methyl-2-pyrrolidone contaminated by various uses by the method of the present invention, batch distillation is different from continuous distillation as described above. It is preferable to adopt the method. That is, a batch distillation column was charged with N-methyl-2-pyrrolidone adjusted to a predetermined water content, and the column bottom temperature was 150 to 250.
While maintaining the temperature at 0 ° C., total reflux is carried out so as to satisfy the condition of T> 150−7ln (θt), and then distillation is performed. Preferably, the bottom temperature of 180 to 230 ° C. is maintained and T
Total reflux is performed under the condition of> 180-7ln (θt). Light-boiling components and water are distilled out at the beginning of distillation, and when these are completely distilled, N-methyl-2-pyrrolidone starts to be distilled. The boiling point of water and N-methyl-2-pyrrolidone is 10
Since the difference is 0 ° C. or more, it is preferable to reduce the pressure when the distillation of water is completed to promote the distillation of N-methyl-2-pyrrolidone.
【０００９】[0009]
【実施例】以下に実施例により本発明を更に詳細に説明
するが、本発明はその要旨を越えない限り以下の実施例
に限定されるものではない。EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.
【００１０】〔実施例−１〕温度２４８℃、圧力３６ｋ
ｇ／ｃｍ2 Ｇに保持されている流通型の反応器にγ−ブ
チロラクトン、メチルアミンおよび水を１：１．１：
４．４のモル比で供給した。反応器での滞留時間は５時
間で、γ−ブチロラクトンの９９．９％以上が反応し、
中間体のＮ−メチル−γ−オキシ酪酸アミドの残存率は
１％未満であった。反応生成液を脱アミン塔に供給し、
常圧下、塔頂温度約１１０℃、塔底温度約１２０℃で蒸
留した。塔頂から留出する蒸気は冷却凝縮してメチルア
ミンの４％水溶液として回収した。Ｎ−メチル−２−ピ
ロリドンは１．０モル倍の水とともに塔底から抜き出し
た。次いで１０段の脱水蒸留塔にて反応生成物の脱水及
び軽沸物除去と同時に熱処理を行った。塔頂圧は常圧、
塔底温度は１８０℃、還流比は１．０で蒸留時間は５時
間とした。缶出液の組成はＮ−メチル−２−ピロリドン
９８重量％、水１重量％以下であった。この溶液を１０
段のオルダーショーカラムにて回分蒸留した。塔頂圧は
８０ｍｍＨｇ、塔頂温度は１３０℃を基準とし、塔底温
度は主留部分で１３５〜１３６℃とした。Example-1 Temperature 248 ° C., Pressure 36 k
γ-butyrolactone, methylamine, and water were added to the flow reactor held at g / cm 2 G of 1: 1.1:
It was fed in a molar ratio of 4.4. The residence time in the reactor is 5 hours, 99.9% or more of γ-butyrolactone reacts,
The residual rate of the intermediate N-methyl-γ-oxybutyric acid amide was less than 1%. The reaction product solution is supplied to the deamine column,
The distillation was carried out under normal pressure at a column top temperature of about 110 ° C and a column bottom temperature of about 120 ° C. The vapor distilled from the top of the column was cooled and condensed and recovered as a 4% aqueous solution of methylamine. N-methyl-2-pyrrolidone was extracted from the bottom of the column together with 1.0 mol of water. Then, heat treatment was performed simultaneously with dehydration of the reaction product and removal of light boiling substances in a 10-stage dehydration distillation column. Tower top pressure is normal pressure,
The bottom temperature was 180 ° C., the reflux ratio was 1.0, and the distillation time was 5 hours. The composition of the bottoms was 98% by weight of N-methyl-2-pyrrolidone and 1% by weight or less of water. Add this solution to 10
Batch distillation was carried out in a column Aldershaw column. The column top pressure was 80 mmHg, the column top temperature was 130 ° C. as a reference, and the column bottom temperature was 135 to 136 ° C. in the main distillation portion.
【００１１】留出率２０〜９０％でのＮ−メチル−２−
ピロリドンの純度は９９重量％以上であり、取得直後の
着色度はＡＰＨＡで１０以下、２４時間経過後のＡＰＨ
Ａも１０以下であり、全く経時着色が見られなかった。
なお、経時着色は蒸留により取得した留分をガラスフラ
スコ中で窒素雰囲気下に室温で保存したものにつき、比
色法によりＡＰＨＡを測定した。N-methyl-2- with a distillation rate of 20 to 90%
The purity of pyrrolidone is 99% by weight or more, the coloring degree immediately after the acquisition is 10 or less by APHA, and the APH after 24 hours have passed.
A was also 10 or less, and no coloring with time was observed.
For coloring with time, APHA was measured by a colorimetric method for a fraction obtained by distillation and stored at room temperature in a glass flask under a nitrogen atmosphere.
【００１２】〔実施例２〜３，比較例１〜２〕実施例１
と同様な方法で反応及び蒸留を行って得た１．０モル倍
の水を同伴したＮ−メチル−２−ピロリドンを熱処理す
るにあたり、塔底温度、熱処理時間を変えた以外は実施
例１と同様に行った。結果を表１に示す。[Examples 2 and 3, Comparative Examples 1 and 2] Example 1
When heat-treating the N-methyl-2-pyrrolidone entrained with 1.0 mole of water obtained by carrying out reaction and distillation in the same manner as in Example 1, except that the column bottom temperature and the heat treatment time were changed. I went the same way. The results are shown in Table 1.
【００１３】[0013]
【表１】 [Table 1]
【００１４】[0014]
【発明の効果】本発明によれば、Ｎ−メチル−２−ピロ
リドンを水の共存下に熱処理したのち蒸留精製すること
により、経時着色の極めて少ないＮ−メチル−２−ピロ
リドンを取得することができる。INDUSTRIAL APPLICABILITY According to the present invention, N-methyl-2-pyrrolidone can be obtained with extremely little coloring over time by heat treating N-methyl-2-pyrrolidone in the presence of water and then purifying by distillation. it can.
Claims (3)
ンを、下記（１）式で示される温度及び時間で熱処理し
たのち蒸留してＮ−メチル−２−ピロリドンを留出させ
ることを特徴とするＮ−メチル−２−ピロリドンの精製
方法。 Ｔ＞１５０−７ｌｎ（θｔ）……（１） （式中、Ｔは温度（℃）、θｔは時間（ｈｒ）を示す）1. N-methyl-2-pyrrolidone containing water is heat-treated at a temperature and a time shown by the following formula (1) and then distilled to distill N-methyl-2-pyrrolidone. And a method for purifying N-methyl-2-pyrrolidone. T> 150-7ln (θt) (1) (where T is temperature (° C) and θt is time (hr))
ンを脱水蒸留塔に供給し、塔内での温度と滞留時間との
関係が Ｔ＞１５０−７ｌｎ（θｔ） （式中、Ｔは温度（℃）、θｔは時間（ｈｒ）を示す）
なる条件を満足するように蒸留して塔頂から水及び軽沸
成分を留出させ、塔底からＮ−メチル−２−ピロリドン
を抜出して精留塔に供給し、精留塔で蒸留して精製され
たＮ−メチル−２−ピロリドンを留出させ、塔底から高
沸成分を抜出すことを特徴とするＮ−メチル−２−ピロ
リドンの精製方法。2. N-methyl-2-pyrrolidone containing water is supplied to a dehydration distillation column, and the relationship between the temperature and the residence time in the column is T> 150-7ln (θt) (where T is Temperature (° C), θt indicates time (hr))
To distill water and light-boiling components from the top of the column, N-methyl-2-pyrrolidone is withdrawn from the bottom of the column, supplied to the rectification column, and distilled in the rectification column. A method for purifying N-methyl-2-pyrrolidone, which comprises distilling out purified N-methyl-2-pyrrolidone and extracting a high-boiling component from the bottom of the column.
ンの含水率が１０〜２０（重量）％であることを特徴と
する請求項１又は２記載のＮ−メチル−２−ピロリドン
の精製方法。3. The method for purifying N-methyl-2-pyrrolidone according to claim 1 or 2, wherein the water content of N-methyl-2-pyrrolidone used for purification is 10 to 20% by weight. .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP05228193A JP3218778B2 (en) | 1993-03-12 | 1993-03-12 | Method for purifying N-methyl-2-pyrrolidone |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP05228193A JP3218778B2 (en) | 1993-03-12 | 1993-03-12 | Method for purifying N-methyl-2-pyrrolidone |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06263725A true JPH06263725A (en) | 1994-09-20 |
| JP3218778B2 JP3218778B2 (en) | 2001-10-15 |
Family
ID=12910418
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP05228193A Expired - Lifetime JP3218778B2 (en) | 1993-03-12 | 1993-03-12 | Method for purifying N-methyl-2-pyrrolidone |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3218778B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011030728A1 (en) | 2009-09-14 | 2011-03-17 | 三菱化学エンジニアリング株式会社 | Nmp distilling apparatus |
| JP2020193177A (en) * | 2019-05-30 | 2020-12-03 | オルガノ株式会社 | N-methyl-2-pyrolidone purification method and purification system |
| JP2020193178A (en) * | 2019-05-30 | 2020-12-03 | オルガノ株式会社 | N-methyl-2-pyrolidone purification method and purification system |
-
1993
- 1993-03-12 JP JP05228193A patent/JP3218778B2/en not_active Expired - Lifetime
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
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| WO2011030728A1 (en) | 2009-09-14 | 2011-03-17 | 三菱化学エンジニアリング株式会社 | Nmp distilling apparatus |
| KR20120093826A (en) | 2009-09-14 | 2012-08-23 | 미츠비시 가가쿠 엔지니어링 가부시키가이샤 | Nmp distilling apparatus |
| US9815000B2 (en) | 2009-09-14 | 2017-11-14 | Mitsubishi Chemical Engineering Corporation | N-methyl-2-pyrrolidone distilling apparatus |
| JP2020193177A (en) * | 2019-05-30 | 2020-12-03 | オルガノ株式会社 | N-methyl-2-pyrolidone purification method and purification system |
| JP2020193178A (en) * | 2019-05-30 | 2020-12-03 | オルガノ株式会社 | N-methyl-2-pyrolidone purification method and purification system |
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| Publication number | Publication date |
|---|---|
| JP3218778B2 (en) | 2001-10-15 |
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