JP2936949B2 - Method for purifying N-methyl-2-pyrrolidone - Google Patents
Method for purifying N-methyl-2-pyrrolidoneInfo
- Publication number
- JP2936949B2 JP2936949B2 JP6847693A JP6847693A JP2936949B2 JP 2936949 B2 JP2936949 B2 JP 2936949B2 JP 6847693 A JP6847693 A JP 6847693A JP 6847693 A JP6847693 A JP 6847693A JP 2936949 B2 JP2936949 B2 JP 2936949B2
- Authority
- JP
- Japan
- Prior art keywords
- pyrrolidone
- methyl
- recovered
- coloring
- distilled
- 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.)
- Expired - Lifetime
Links
Landscapes
- Pyrrole Compounds (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、回収Ｎ−メチル−２−
ピロリドン、すなわち溶剤などとして用いられたＮ−メ
チル−２−ピロリドンを精製する方法に関するものであ
る。特に本発明に回収Ｎ−メチル−２−ピロリドンか
ら、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。The present invention relates to a method for recovering N-methyl-2-
The present invention relates to a method for purifying pyrrolidone, that is, N-methyl-2-pyrrolidone used as a solvent or the like. In particular, the present invention relates to a method for obtaining N-methyl-2-pyrrolidone, which is significantly less colored with time, from recovered N-methyl-2-pyrrolidone.
【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
広く用いられている。また、最近では、Ｎ−メチル−２
−ピロリドンに少量の水を添加したものが、ハロゲン化
炭化水素系溶剤に代る洗浄剤として注目されている。2. Description of the Related Art N-methyl-2-pyrrolidone is widely used as a solvent because it is nontoxic, has high heat resistance and is chemically stable. Recently, N-methyl-2
A substance obtained by adding a small amount of water to pyrrolidone is attracting attention as a cleaning agent that can replace a halogenated hydrocarbon solvent.
【０００３】[0003]
【発明が解決しようとする課題】Ｎ−メチル−２−ピロ
リドンは着色し易い物質なので、種々の用途から回収さ
れたＮ−メチル−２−ピロリドンは一般に着色してい
る。このような着色した回収Ｎ−メチル−２−ピロリド
ンから着色のないＮ−メチル−２−ピロリドンを取得す
る方法が検討されているが、未だ満足すべき方法は知ら
れていない。例えば着色した回収Ｎ−メチル−２−ピロ
リドンを活性炭などの吸着剤で処理すると一時的に着色
を除くことができるが、保存中に再び着色する。回収Ｎ
−メチル−２−ピロリドンの価値を高めるには、経時着
色の少ないＮ−メチル−２−ピロリドンを与える精製法
の開発が必要である。従って、本発明は回収Ｎ−メチル
−２−ピロリドンから経時着色の少ないＮ−メチル−２
−ピロリドンを取得する方法を提供せんとするものであ
るるSince N-methyl-2-pyrrolidone is an easily colored substance, N-methyl-2-pyrrolidone recovered from various uses is generally colored. A method for obtaining N-methyl-2-pyrrolidone without color from such colored recovered N-methyl-2-pyrrolidone has been studied, but a satisfactory method has not yet been known. For example, if colored N-methyl-2-pyrrolidone is treated with an adsorbent such as activated carbon, the coloring can be temporarily removed, but the color is recolored during storage. Collection N
In order to increase the value of -methyl-2-pyrrolidone, it is necessary to develop a purification method which gives N-methyl-2-pyrrolidone with less coloring over time. Therefore, the present invention provides N-methyl-2 with less coloring with time from recovered N-methyl-2-pyrrolidone.
-To provide a method for obtaining pyrrolidone
【０００４】[0004]
【課題を解決するための手段】本発明によれば、着色し
ており、かつ実質的に水を含有していない回収Ｎ−メチ
ル−２−ピロリドンを、１３５℃以上の温度に３０分間
以上保持したのち蒸留して軽沸不純物を留出させ、次い
でＮ−メチル−２−ピロリドンを留出させることによ
り、着色がなく、かつ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。According to the present invention, the recovered N-methyl-2-pyrrolidone, which is colored and substantially free of water, is kept at a temperature of 135 ° C. or more for 30 minutes or more. Thereafter, distillation is performed to distill light-boiling impurities, and then N-methyl-2-pyrrolidone is distilled off, whereby N-methyl-2-pyrrolidone having no coloring and extremely little coloring with time can be obtained. it can.
【０００５】本発明について更に詳細に説明するに、本
発明で精製の対象とするのは、溶剤その他の工業用途に
用いられて着色しており、かつ含水率が１重量％以下と
いうような実質的に水を含有していない回収Ｎ−メチル
−２−ピロリドンである。本発明では、この回収Ｎ−メ
チル−２−ピロリドンを熱処理したのち蒸留する。熱処
理により回収Ｎ−メチル−２−ピロリドンに如何なる変
化が生ずるのかは不明であるが、着色の原因となる物質
が熱分解するか又は高沸点物質に変化するものと考えら
れる。熱処理は１３５℃以上、好ましくは１５０〜２５
０℃の温度で行なう。熱処理に要する時間は３０分間以
上、好ましくは１〜１０時間である。The present invention will be described in further detail. In the present invention, a substance to be purified is a substance which is colored for use in a solvent or other industrial uses and has a water content of 1% by weight or less. Recovered N-methyl-2-pyrrolidone which does not contain water. In the present invention, the recovered N-methyl-2-pyrrolidone is subjected to heat treatment and then distilled. It is not known what change occurs in the recovered N-methyl-2-pyrrolidone due to the heat treatment, but it is considered that the substance causing the coloring is thermally decomposed or changes to a high boiling substance. Heat treatment is 135 ° C or higher, preferably 150 to 25
Perform at a temperature of 0 ° C. The time required for the heat treatment is 30 minutes or more, preferably 1 to 10 hours.
【０００６】熱処理を経た回収Ｎ−メチル−２−ピロリ
ドンは次いで蒸留精製する。蒸留精製は先ず軽沸不純物
を留出させて除去し、次いで高純度のＮ−メチル−２−
ピロリドンを留出させる。蒸留塔の操作条件は塔頂圧力
１０〜７６０ｍｍＨｇ、塔底温度８０〜２２０℃が好ま
しい。回収Ｎ−メチル−２−ピロリドンの熱処理は、加
熱手段を備えた密閉しうる容器であれば任意の装置で行
なうことができる。熱処理装置を別に設けない場合に
は、蒸留塔に回収Ｎ−メチル−２−ピロリドンを仕込ん
で全還流により熱処理し、次いで蒸留を行なえばよい。[0006] The recovered N-methyl-2-pyrrolidone after the heat treatment is then purified by distillation. In the distillation purification, first, light-boiling impurities are removed by distillation, and then high-purity N-methyl-2-
Distill the pyrrolidone. The operating conditions of the distillation column are preferably a top pressure of 10 to 760 mmHg and a bottom temperature of 80 to 220 ° C. The heat treatment of the recovered N-methyl-2-pyrrolidone can be performed by any device as long as it is a hermetically sealed container provided with a heating means. When a heat treatment apparatus is not separately provided, the recovered N-methyl-2-pyrrolidone is charged into a distillation column, heat-treated by total reflux, and then distillation is performed.
【０００７】[0007]
【実施例】以下に実施例により本発明をさらに具体的に
説明するが、本発明はその要旨を超えない限り、以下の
実施例に限定されるものではない。 〔実施例１〕実段数１７段を有する蒸留塔に、工業用途
に用いられて淡黄色に着色したＮ−メチル−２−ピロリ
ドンを仕込み、常圧下に塔底温度１３７℃で１時間熱処
理を行なった。次いで塔頂圧力８８ｍｍＨｇで蒸留し、
塔頂温度１２５〜１３２℃でＮ−メチル−２−ピロリド
ンと共に軽沸不純物を留出させた（回収率９．２％）。
次いで塔頂温度１３２℃、塔底温度１３５〜１３９℃で
Ｎ−メチル−２−ピロリドンを留出させた（回収率８
３．８％）。このＮ−メチル−２−ピロリドンの純度は
９９．９％以上であった。着色度はＡＰＨＡ１０であ
り、７日経過してもＡＰＨＡの変化は見られなかった。
なお、ＡＰＨＡはＡＳＴＭ Ｄ−１２０９に準じて測定
した。また、ＡＰＨＡの経時変化は、留出したＮ−メチ
ル−２−ピロリドンをガラスフラスコ中で窒素雰囲気下
に室温放置したものについて測定した。EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited to the following Examples without departing from the scope of the invention. Example 1 A pale yellow N-methyl-2-pyrrolidone used for industrial use was charged into a distillation column having 17 actual plates, and heat-treated at normal temperature and a bottom temperature of 137 ° C. for 1 hour. Was. Then, distillation was performed at a top pressure of 88 mmHg,
Light boiling impurities were distilled off together with N-methyl-2-pyrrolidone at an overhead temperature of 125 to 132 ° C (recovery rate: 9.2%).
Next, N-methyl-2-pyrrolidone was distilled off at a tower top temperature of 132 ° C and a tower bottom temperature of 135 to 139 ° C (recovery rate: 8).
3.8%). The purity of this N-methyl-2-pyrrolidone was 99.9% or more. The coloring degree was APHA10, and no change in APHA was observed even after 7 days.
In addition, APHA was measured according to ASTM D-1209. The time-dependent change of APHA was measured for the distilled N-methyl-2-pyrrolidone which was left at room temperature under a nitrogen atmosphere in a glass flask.
【０００８】〔実施例２〕実施例１の方法において、塔
頂圧力を４０ｍｍＨｇとしてＮ−メチル−２−ピロリド
ンと共に軽沸不純物を留出（回収率５．１％）させ、次
いで塔頂温度１１２℃、塔底温度１１６〜１２４℃でＮ
−メチル−２−ピロリドンを留出させた（回収率８９．
３％）以外は、実施例１と同様にしてＮ−メチル−２−
ピロリドンの精製を行なった。取得されたＮ−メチル−
２−ピロリドンの純度は９９．９％以上であった。着色
度はＡＰＨＡ１０であり、７日経過してもＡＰＨＡの変
化は見られなかった。Example 2 In the method of Example 1, light-boiling impurities were distilled off together with N-methyl-2-pyrrolidone (recovery rate: 5.1%) at a top pressure of 40 mmHg, and then a top temperature of 112 ° C, N at tower bottom temperature 116-124 ° C
-Methyl-2-pyrrolidone was distilled off (recovery 89.
3%) except that N-methyl-2-
The pyrrolidone was purified. N-methyl- obtained
The purity of 2-pyrrolidone was 99.9% or more. The coloring degree was APHA10, and no change in APHA was observed even after 7 days.
【０００９】〔実施例３〕実施例１で用いた蒸留塔に工
業用途に用いられて淡黄色に着色したＮ−メチル−２−
ピロリドンを仕込み、常圧下に塔底温度１５０℃で３０
分間熱処理を行なった。次いで常圧蒸留し、塔頂温度１
９９〜２０３℃でＮ−メチル−２−ピロリドンと共に軽
沸不純物を留出させた（回収率５．２％）。さらに塔頂
温度２０３〜２０４℃、塔底温度２０５〜２０７℃でＮ
−メチル−２−ピロリドンを留出させた（回収率８７．
０％）。取得されたＮ−メチル−２−ピロリドンの純度
は９９．９％以上であった。着色度はＡＰＨＡ１０であ
り、７日経過してもＡＰＨＡの変化は見られなかった。Example 3 N-methyl-2-colored pale yellow used in the distillation column used in Example 1 for industrial purposes
Pyrrolidone was charged, and the temperature was 30
Heat treatment was performed for minutes. Then, the mixture was distilled under atmospheric pressure and the top temperature was 1
Light boiling impurities were distilled out together with N-methyl-2-pyrrolidone at 99 to 203 ° C (recovery rate 5.2%). Further, at a tower top temperature of 203 to 204 ° C and a tower bottom temperature of 205 to 207 ° C,
-Methyl-2-pyrrolidone was distilled off (recovery 87.
0%). The purity of the obtained N-methyl-2-pyrrolidone was 99.9% or more. The coloring degree was APHA10, and no change in APHA was observed even after 7 days.
【００１０】〔比較例１〕実施例１で用いた蒸留塔に、
工業用途に用いられて淡黄色に着色したＮ−メチル−２
−ピロリドンを仕込み、熱処理することなく塔頂圧力１
０ｍｍＨｇで蒸留して、Ｎ−メチル−２−ピロリドンと
共に軽沸不純物を留出させた（回収率４．２％）。次い
で塔頂温度８２℃、塔底温度１０７〜１１５℃でＮ−メ
チル−２−ピロリドンを留出させた（回収率９２％）。
取得されたＮ−メチル−２−ピロリドンの純度は９９．
４％であった。また着色度は、取得直後はＡＰＨＡ１０
であったが、２日後はＡＰＨＡ５０、３日後はＡＰＨＡ
８０と経時着色が進行した。Comparative Example 1 The distillation column used in Example 1
N-methyl-2 colored pale yellow used for industrial purposes
-Pyrrolidone is charged and the top pressure is 1 without heat treatment
Distillation was carried out at 0 mmHg to distill light-boiling impurities together with N-methyl-2-pyrrolidone (recovery rate: 4.2%). Then, N-methyl-2-pyrrolidone was distilled off at a top temperature of 82 ° C and a bottom temperature of 107 to 115 ° C (recovery rate 92%).
The purity of the obtained N-methyl-2-pyrrolidone is 99.
4%. Immediately after the acquisition, the degree of coloring was APHA10.
2 days later, APHA50 after 3 days, APHA after 3 days
80 and coloring with time progressed.
【００１１】〔比較例２〕比較例１の方法において、軽
沸不純物を回収率１１．２％に達するまで留出させたの
ち、主留分を回収率７８％で取得した。取得されたＮ−
メチル−２−ピロリドンの純度は９９．９％であった。
また、着色度は、取得直後はＡＰＨＡ１０であったが、
２日後はＡＰＨＡ２０、３日後はＡＰＨＡ２５、７日後
はＡＰＨＡ３５と経時着色が進んだ。Comparative Example 2 In the method of Comparative Example 1, light-boiling impurities were distilled off until the recovery rate reached 11.2%, and then a main fraction was obtained at a recovery rate of 78%. Acquired N-
The purity of methyl-2-pyrrolidone was 99.9%.
The coloring degree was APHA10 immediately after the acquisition,
Two days later, APHA20, three days later, APHA25, seven days later, APHA35, coloring with time progressed.
【００１２】[0012]
【発明の効果】本発明によれば、着色した回収Ｎ−メチ
ル−２−ピロリドンを熱処理したのち蒸留することによ
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。According to the present invention, it is possible to obtain N-methyl-2-pyrrolidone having extremely little coloring over time by subjecting the recovered N-methyl-2-pyrrolidone which has been colored to a heat treatment and then distillation.
フロントページの続き (58)調査した分野(Int.Cl.6，ＤＢ名) C07D 207/00 - 207/50 C07B 63/00 ＣＡ（ＳＴＮ) ＣＡＯＬＤ（ＳＴＮ) ＲＥＧＩＳＴＲＹ（ＳＴＮ)Continued on the front page (58) Fields surveyed (Int. Cl. 6 , DB name) C07D 207/00-207/50 C07B 63/00 CA (STN) CAOLD (STN) REGISTRY (STN)
Claims (1)
ていない回収Ｎ−メチル−２−ピロリドンを、１３５℃
以上の温度に３０分間以上保持したのち蒸留して軽沸不
純物を留出させ、次いで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。1. The recovered N-methyl-2-pyrrolidone, which is colored and substantially free of water, is treated at 135 ° C.
A method for purifying N-methyl-2-pyrrolidone, comprising maintaining the above-mentioned temperature for 30 minutes or more, distilling light-boiling impurities by distillation, and then distilling N-methyl-2-pyrrolidone.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6847693A JP2936949B2 (en) | 1993-03-26 | 1993-03-26 | Method for purifying N-methyl-2-pyrrolidone |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6847693A JP2936949B2 (en) | 1993-03-26 | 1993-03-26 | Method for purifying N-methyl-2-pyrrolidone |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06279401A JPH06279401A (en) | 1994-10-04 |
| JP2936949B2 true JP2936949B2 (en) | 1999-08-23 |
Family
ID=13374782
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6847693A Expired - Lifetime JP2936949B2 (en) | 1993-03-26 | 1993-03-26 | Method for purifying N-methyl-2-pyrrolidone |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2936949B2 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101415673B (en) * | 2006-04-06 | 2011-02-02 | 巴斯夫欧洲公司 | Process for the preparation of an N-alkyl lactam with improved colour quality |
| JP5471221B2 (en) | 2009-09-14 | 2014-04-16 | 三菱化学エンジニアリング株式会社 | NMP distillation equipment |
| CN102399179B (en) * | 2010-09-17 | 2014-06-18 | 上海化学试剂研究所 | Production process for ultra-pure N-methylpyrrolidone |
| CN104797558B (en) * | 2012-11-22 | 2017-05-24 | 巴斯夫欧洲公司 | Method for purifying N-alkylpyrrolidones |
| 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 |
| 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 |
-
1993
- 1993-03-26 JP JP6847693A patent/JP2936949B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH06279401A (en) | 1994-10-04 |
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