JP2000344688A - Purification of readily polymerizable compound - Google Patents
Purification of readily polymerizable compoundInfo
- Publication number
- JP2000344688A JP2000344688A JP11157641A JP15764199A JP2000344688A JP 2000344688 A JP2000344688 A JP 2000344688A JP 11157641 A JP11157641 A JP 11157641A JP 15764199 A JP15764199 A JP 15764199A JP 2000344688 A JP2000344688 A JP 2000344688A
- Authority
- JP
- Japan
- Prior art keywords
- polymerizable compound
- cooling
- easily polymerizable
- polymerization inhibitor
- heat exchanger
- 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.)
- Pending
Links
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、アクリル酸、メタ
クリル酸（以下この両者をまとめて（メタ）アクリル
酸」と記載する）、（メタ）アクリル酸エステルやスチ
レン等の、分子内に重合性二重結合を有する易重合性化
合物を精製する方法に関するものである。詳しくは、易
重合性化合物の蒸留を効率的かつ安全に行うための精製
方法に関するものである。BACKGROUND OF THE INVENTION The present invention relates to a polymerizable compound such as acrylic acid, methacrylic acid (hereinafter, both of which are collectively referred to as "(meth) acrylic acid"), (meth) acrylic acid ester and styrene. The present invention relates to a method for purifying an easily polymerizable compound having a double bond. More particularly, the present invention relates to a purification method for efficiently and safely distilling an easily polymerizable compound.
【０００２】[0002]
【従来の技術】分子内に二重結合、特に炭素−炭素二重
結合を有する化合物は、一般に反応性に富み、重合しや
すい。このような化合物を取り扱うプロセス、特にその
精製工程において、重合が起こった場合、製品収率の低
下及び重合体の付着やそれに起因する配管等の閉塞等に
よる設備の操業トラブルの原因となる可能性がある。そ
のため、このような易重合性化合物を蒸留により精製す
る場合は、重合を防止するために、フェノチアジン、ｐ
−メトキシフェノール（通称「メトキシハイドロキノ
ン」、「メトキノン」）、ハイドロキノン及び銅化合物
等の種々の金属またはその化合物、或いは酸素または酸
素含有ガス等の重合禁止剤を添加して蒸留する方法や、
これに加えて処理温度を低くして重合を抑えるため高真
空下で蒸留を行う方法などが広く用いられている。2. Description of the Related Art Compounds having a double bond, particularly a carbon-carbon double bond, in the molecule are generally rich in reactivity and easily polymerized. If polymerization occurs in the process of handling such compounds, especially in the purification process, it may cause a decrease in product yield and cause equipment trouble due to adhesion of the polymer and clogging of piping etc. There is. Therefore, when such an easily polymerizable compound is purified by distillation, phenothiazine, p
-Methoxyphenol (commonly referred to as "methoxyhydroquinone", "methquinone"), a method of adding various metals such as hydroquinone and copper compounds or compounds thereof, or a polymerization inhibitor such as oxygen or an oxygen-containing gas, and distilling;
In addition to this, a method of performing distillation under a high vacuum in order to suppress the polymerization by lowering the processing temperature is widely used.
【０００３】しかしながら、このような重合禁止剤は一
般に蒸気圧が低く、蒸留塔の塔頂の蒸気中には、ほとん
ど存在しないため、塔頂から留出する蒸気の冷却・凝縮
を行う熱交換器や、蒸留塔頂から熱交換器に至る配管内
で、易重合性化合物の重合が起こり、連続運転が困難と
なることがあった。[0003] However, such a polymerization inhibitor generally has a low vapor pressure and is hardly present in the vapor at the top of the distillation column. Therefore, a heat exchanger for cooling and condensing the vapor distilled from the top of the distillation column is used. Also, polymerization of the easily polymerizable compound may occur in a pipe extending from the distillation tower top to the heat exchanger, making continuous operation difficult.
【０００４】[0004]
【発明が解決しようとする課題】本発明の課題は、易重
合性化合物の蒸留による精製に際して、この冷却・凝縮
部分での重合を防止することにより、精製を効率的かつ
安全に行うための方法を提供することである。SUMMARY OF THE INVENTION An object of the present invention is to provide a method for efficiently and safely purifying an easily polymerizable compound by preventing polymerization in a cooling / condensing portion during purification by distillation. It is to provide.
【０００５】[0005]
【課題を解決するための手段】本発明者らは、上記の問
題を解決するために、種々の検討・評価を行った結果、
蒸留塔の塔頂蒸気の冷却・凝縮を特定の方法によって行
うことにより、これらの問題点が解決できることを見出
し、本発明を完成した。即ち、本発明の要旨は、易重合
性化合物を含む液を蒸留するに際して、蒸留塔の塔頂蒸
気の冷却・凝縮装置を、その凝縮面が鉛直となるように
設置し、かつ該凝縮面上に重合禁止剤を存在させること
を特徴とする易重合性化合物の精製方法、に存してい
る。Means for Solving the Problems The present inventors have conducted various studies and evaluations in order to solve the above problems.
The inventors have found that these problems can be solved by cooling and condensing the vapor at the top of the distillation column by a specific method, and completed the present invention. That is, the gist of the present invention is that, when distilling a liquid containing an easily polymerizable compound, a cooling / condensing device for the vapor at the top of the distillation column is installed so that the condensing surface is vertical, and on the condensing surface A method for purifying an easily polymerizable compound, characterized by including a polymerization inhibitor.
【０００６】また、本発明の他の要旨は、蒸気の冷却・
凝縮装置の凝縮面の上部に重合禁止剤を含む液を噴霧す
る前記の易重合性化合物の精製方法にも存している。更
に、本発明の別の要旨は、蒸気の冷却・凝縮装置を蒸留
塔の塔頂直近に設置する前記の易重合性化合物の精製方
法、及び蒸留塔の塔頂から蒸気の冷却・凝縮装置の入口
に至る配管を、蒸気の凝縮温度より高い温度に維持する
前記の易重合性化合物の精製方法、にも存している。[0006] Another aspect of the present invention is to provide steam cooling and cooling.
The present invention also resides in the above-mentioned method for purifying an easily polymerizable compound, in which a liquid containing a polymerization inhibitor is sprayed on an upper portion of a condensation surface of a condenser. Further, another gist of the present invention is to provide a method for purifying an easily polymerizable compound, in which a steam cooling / condensing apparatus is installed immediately near the top of a distillation column, and a method for cooling / condensing steam from the top of a distillation column. The above-mentioned method for purifying an easily polymerizable compound, wherein the pipe leading to the inlet is maintained at a temperature higher than the condensation temperature of steam also exists.
【０００７】本発明のもう一つの要旨は、易重合性化合
物が（メタ）アクリル酸及び（メタ）アクリル酸エステ
ルから選ばれる少なくとも１種の化合物である上述の易
重合性化合物の精製方法、及び重合禁止剤が、ｐ−メト
キシフェノール、ハイドロキノン、フェノチアジン及び
銅化合物からなる群から選ばれる少なくとも１種の化合
物である上述の易重合性化合物の精製方法、にも存して
いる。[0007] Another gist of the present invention is a method for purifying the above-mentioned easily polymerizable compound, wherein the easily polymerizable compound is at least one compound selected from (meth) acrylic acid and (meth) acrylate. The method for purifying an easily polymerizable compound described above, wherein the polymerization inhibitor is at least one compound selected from the group consisting of p-methoxyphenol, hydroquinone, phenothiazine and a copper compound.
【０００８】[0008]
【発明の実施の形態】以下、本発明を更に詳細に説明す
る。本発明は、易重合性化合物を蒸留により精製する方
法を改良したものである。本発明方法を適用することが
できる易重合性化合物としては、アクリル酸、メタクリ
ル酸等の不飽和カルボン酸、メタクリル酸メチル、アク
リル酸ブチル、アクリル酸オクチル、アクリル酸２−ヒ
ドロキシエチル、アクリル酸２−ヒドロキシプロピル、
メタクリル酸ブチル等の（メタ）アクリル酸エステルを
含む不飽和カルボン酸エステル類、アクリロニトリル、
アクリルアミドのようなアクリル化合物、スチレン等の
芳香族ビニル化合物等が例示できる。BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The present invention is an improved method for purifying an easily polymerizable compound by distillation. Examples of the easily polymerizable compound to which the method of the present invention can be applied include unsaturated carboxylic acids such as acrylic acid and methacrylic acid, methyl methacrylate, butyl acrylate, octyl acrylate, 2-hydroxyethyl acrylate, acrylic acid 2 -Hydroxypropyl,
Unsaturated carboxylic esters including (meth) acrylates such as butyl methacrylate, acrylonitrile,
Acrylic compounds such as acrylamide and aromatic vinyl compounds such as styrene can be exemplified.
【０００９】本発明方法は、これらの中でも、特に（メ
タ）アクリル酸及び（メタ）アクリル酸エステルから選
ばれる少なくとも１種の化合物を含む液の蒸留精製に用
いるのが効果的である。蒸留においては、塔頂に低沸点
成分の蒸気を留出させ、これを配管により冷却・凝縮装
置へ導き、ここで塔頂蒸気を冷却して凝縮させて塔頂液
を得、その一部を還流液として蒸留塔へ循環し、残りを
次工程に供給する。この次工程は、蒸留の目的によって
例えば製品化工程、有効成分の回収工程、排出成分処理
工程、等があるが、本発明は易重合性化合物が蒸留され
る限り、そのいずれの場合においても効果的である。[0009] The method of the present invention is particularly effective for distillation purification of a liquid containing at least one compound selected from (meth) acrylic acid and (meth) acrylic acid ester. In the distillation, a low-boiling component vapor is distilled off at the top of the column, which is led to a cooling / condensing device via piping, where the top vapor is cooled and condensed to obtain a top liquid, and a part of the liquid is obtained. It is circulated to the distillation column as a reflux liquid, and the remainder is supplied to the next step. This next step includes, for example, a productization step, a step of recovering an active ingredient, a step of treating a discharged component, and the like depending on the purpose of distillation. However, the present invention is effective in any case as long as the easily polymerizable compound is distilled. It is a target.
【００１０】本発明方法においては、蒸留塔の塔頂蒸気
の冷却・凝縮装置は、その凝縮面が鉛直となるように設
置される。ここで冷却・凝縮装置として使用できるもの
としては、熱交換器が挙げられ、その形式としては例え
ば、多管式円筒型熱交換器、空冷熱交換器、二重管式熱
交換器、コイル式熱交換器、プレート式熱交換器、及び
スパイラル式熱交換器などが例示できる。In the method of the present invention, the apparatus for cooling and condensing the vapor at the top of the distillation column is installed so that the condensation surface is vertical. Here, as a device that can be used as a cooling / condensing device, a heat exchanger can be used. Examples thereof include a heat exchanger, a plate heat exchanger, and a spiral heat exchanger.
【００１１】本発明においては、この熱交換器の凝縮面
を鉛直となるように設置することを特徴としている。こ
こで「鉛直」とは、水平面に対して垂直であると言う通
常の意味に加えて、本発明のもう一つの特徴である当該
凝縮面上に重合禁止剤が偏在しないようにできる程度の
傾きを有しているものまでをも包含する。具体的には、
水平面に対して約８０°程度以上の角度、好ましくは８
５°以上、より好ましくは８８°以上、更に好ましくは
８９°以上の角度となっていればよい。熱交換器の凝縮
面を鉛直にすることにより、易重合性化合物の凝縮液を
不必要に滞留させることなく流すことができ、かつ下記
の重合禁止剤を含む液を流下させる場合にも、その液の
流れの偏りがなくなるので効率的である。[0011] The present invention is characterized in that the condensing surface of the heat exchanger is installed vertically. Here, “vertical” means, in addition to the usual meaning of being perpendicular to the horizontal plane, an inclination that can prevent the polymerization inhibitor from being unevenly distributed on the condensation surface, which is another feature of the present invention. And those having In particular,
An angle of about 80 ° or more to the horizontal plane, preferably 8
The angle should be at least 5 °, more preferably at least 88 °, even more preferably at least 89 °. By making the condensing surface of the heat exchanger vertical, the condensate of the easily polymerizable compound can be flowed without unnecessarily staying, and when the liquid containing the following polymerization inhibitor is allowed to flow down, This is efficient because there is no bias in the flow of the liquid.
【００１２】上記の通り、本発明方法においては蒸気の
冷却・凝縮装置の凝縮面上に重合禁止剤を存在させる。
これを達成するための方法としては、例えば重合禁止剤
を含有する塗膜を凝縮面上に塗布・形成する、凝縮面を
重合禁止作用のある材料で形成する、或いは重合禁止剤
又はこれを含む液を凝縮面上を流下させる、等が挙げら
れる。これらの方法の内、本発明においては、重合禁止
剤又はこれを含む液を凝縮面上を流下させる方法が、操
作が簡便であるので好ましい。このための具体的方法と
しては、例えば冷却・凝縮装置の凝縮面の上部に重合禁
止剤を含む液を噴霧すればよい。As described above, in the method of the present invention, a polymerization inhibitor is present on the condensation surface of the steam cooling / condensing device.
As a method for achieving this, for example, a coating film containing a polymerization inhibitor is applied and formed on a condensing surface, the condensing surface is formed of a material having a polymerization inhibiting action, or a polymerization inhibitor or a mixture containing the same. And letting the liquid flow down on the condensing surface. Among these methods, in the present invention, a method in which a polymerization inhibitor or a liquid containing the same is caused to flow down on a condensing surface is preferable because the operation is simple. As a specific method for this, for example, a liquid containing a polymerization inhibitor may be sprayed on the condensing surface of the cooling / condensing device.
【００１３】前記の熱交換器の内、このように凝縮面を
鉛直になるように設置するのが容易な熱交換器として
は、例えば多管式熱交換器、プレート式熱交換器、及び
スパイラル熱交換器が挙げられ、本発明に用いるのに好
適である。多管式熱交換器の場合は熱交換用のチューブ
を鉛直方向となるように設置する。この熱交換用チュー
ブの本数は１本でもよいが、多数の熱交換用チューブを
有する多管式熱交換器が必要な伝熱面積を得るためには
有利である。Among the above-mentioned heat exchangers, examples of such heat exchangers that can be easily installed such that the condensing surface is vertical are, for example, a multi-tube heat exchanger, a plate heat exchanger, and a spiral heat exchanger. A heat exchanger is mentioned, and is suitable for use in the present invention. In the case of a multi-tube heat exchanger, the tubes for heat exchange are installed vertically. Although the number of the heat exchange tubes may be one, it is advantageous to obtain a necessary heat transfer area by a multi-tube heat exchanger having a large number of heat exchange tubes.
【００１４】なお、この多管式熱交換器では熱交換用の
チューブが折り返し部分を持っている（Ｕ字管式）熱交
換器もあるが、折り返し部分で液の偏流や滞留が起こり
やすいので、あまり好ましくない。プレート式熱交換器
は、凹凸面を有する板状の伝熱プレートの周囲を接合し
た構造で、これによって形成される空隙室に冷熱媒体と
被処理流体とを交互に流して熱交換させるものであり、
所要伝熱面積によって複数枚の伝熱プレートを組み合わ
せて使用される。この伝熱プレートの面を鉛直方向に設
置することにより、本発明の方法が達成できる。In this multi-tube heat exchanger, there is also a heat exchanger in which a tube for heat exchange has a folded portion (U-tube type). However, the liquid tends to drift or stay in the folded portion. , Not very good. The plate type heat exchanger is a structure in which the periphery of a plate-shaped heat transfer plate having an uneven surface is joined, and a cooling medium and a fluid to be processed are alternately flowed through a gap formed thereby to exchange heat. Yes,
A plurality of heat transfer plates are used in combination depending on the required heat transfer area. By arranging the surface of the heat transfer plate vertically, the method of the present invention can be achieved.
【００１５】スパイラル熱交換器は２枚の伝熱板の上下
を接合し、これを一定の間隔で渦巻き状に巻くことによ
り２つの流路を構成したもので、一方の流路に冷熱媒体
を、他方の流路に被処理流体を流して熱交換を行わせる
構造となっている。この伝熱板の面を鉛直方向とする。
蒸留塔の塔頂蒸気の導入流路は、凝縮した液及び重合禁
止剤を含む液の流れが円滑になるよう、熱交換器上部に
接続することが好ましい。The spiral heat exchanger is composed of two heat transfer plates joined at the top and bottom and spirally wound at a constant interval to form two flow passages. A cooling medium is supplied to one of the flow passages. In this structure, the fluid to be treated flows through the other flow path to perform heat exchange. The surface of the heat transfer plate is defined as a vertical direction.
It is preferable to connect the top vapor introduction flow path of the distillation column to the upper part of the heat exchanger so that the flow of the condensed liquid and the liquid containing the polymerization inhibitor is smooth.
【００１６】また、冷却用の媒体は、蒸気の流れ方向に
対し向流となるようにするのが、熱交換器の効率という
点からは一般的であるが、易重合性化合物の重合防止の
点からは、向流・並流のいずれであっても構わない。熱
交換器の凝縮面上に重合禁止剤を存在させるために、重
合禁止剤又はこれを含む液を凝縮面上を流下させる方法
を用いる場合、この液としては、重合禁止剤が液状であ
ればそのまま使用することも可能であるが、通常は重合
禁止剤を液状の媒体中に溶解又は分散させた液を用いる
のがよい。この液状の媒体としては、蒸留の対象となっ
ている易重合性化合物を用いるのが好ましく、例えば上
記の凝縮液の一部や蒸留塔の塔底液の一部、あるいは蒸
留塔の供給後の一部を抜き出して用いるのが好適である
が、重合禁止剤の溶解力が大きいものであれば、他の溶
媒を用いても構わない。この重合禁止剤を含む液を、冷
却・凝縮装置の凝縮面の上部に噴霧する方法を用いるの
が、上述の通り簡便かつ効率的である。例えば、シャワ
ー状に凝縮面の上部に重合禁止剤を含む液をかけても、
スリット状の隙間からカーテンフロー状になるように流
下させてもよいが、一流体ノズルや二流体ノズル等の噴
霧ノズルを使用して、５〜５００μｍ程度の液滴径とな
るように噴霧するのが偏流防止と効率の点で好ましい。Although the cooling medium is generally countercurrent to the flow direction of steam, from the viewpoint of the efficiency of the heat exchanger, it is generally used to prevent polymerization of the easily polymerizable compound. From the point, it may be either countercurrent or cocurrent. In order to cause the polymerization inhibitor to be present on the condensation surface of the heat exchanger, when using a method of causing the polymerization inhibitor or a liquid containing the same to flow down on the condensation surface, if the polymerization inhibitor is in a liquid state, Although it is possible to use it as it is, it is usually preferable to use a liquid in which a polymerization inhibitor is dissolved or dispersed in a liquid medium. As the liquid medium, it is preferable to use an easily polymerizable compound that is a target of distillation, for example, a part of the condensate or a part of the bottom liquid of the distillation column, or after the supply of the distillation column. It is preferable to use a part of the polymerization inhibitor, but other solvents may be used as long as they have a high dissolving power of the polymerization inhibitor. It is simple and efficient to spray the liquid containing the polymerization inhibitor onto the upper part of the condensing surface of the cooling / condensing device as described above. For example, even if a solution containing a polymerization inhibitor is applied to the upper part of the condensation surface in the form of a shower,
It may be allowed to flow down from the slit-shaped gap so as to form a curtain flow, but using a spray nozzle such as a one-fluid nozzle or a two-fluid nozzle, spraying to a droplet diameter of about 5 to 500 μm Is preferable in terms of prevention of drift and efficiency.
【００１７】本発明方法において使用できる重合禁止剤
としては、特に限定されないが、例えば、ｐ−メトキシ
フェノール、ハイドロキノン及びフェノチアジンなどが
効果と溶解・分散性の点で好適である。また銅化合物の
ような金属化合物も使用できる。重合禁止効果を高める
ために、酸素の存在下で蒸留しても問題ない。一般に、
蒸留塔の塔頂温度は４０〜１００℃と外気温より高い場
合が多い。蒸留塔の塔頂から蒸気の冷却・凝縮装置の入
口に至る配管中で塔頂蒸気が外気により冷却されて一部
凝縮した場合、この凝縮した易重合性化合物は、重合禁
止剤を含まないので重合しやすく、その結果、配管の閉
塞等を起こす場合がある。The polymerization inhibitor that can be used in the method of the present invention is not particularly limited, but, for example, p-methoxyphenol, hydroquinone, phenothiazine and the like are suitable in terms of effect and dissolution / dispersibility. Metal compounds such as copper compounds can also be used. There is no problem if distillation is carried out in the presence of oxygen in order to enhance the polymerization inhibiting effect. In general,
The top temperature of the distillation column is often 40 to 100 ° C., which is higher than the outside temperature. If the overhead vapor is cooled by the outside air and partially condensed in the pipe from the top of the distillation column to the inlet of the vapor cooling / condensing device, this condensed easily polymerizable compound does not contain a polymerization inhibitor. It is easy to polymerize, and as a result, the pipe may be blocked.
【００１８】従って、蒸気の冷却・凝縮装置を蒸留塔の
塔頂直近に設置して、この部分をできるだけ短くし、ま
たこの配管を、蒸気の凝縮温度より高い温度に維持する
のが好ましい。このためには、この配管に保温材を施す
だけでなく、スチームライン又は温水ラインを配管周囲
に設置して必要に応じて加熱できるようにしておくこと
が好ましい。本発明の易重合性化合物の精製方法は、蒸
留によって取得しようとする目的物質が易重合性化合物
である場合だけでなく、易重合性化合物が反応生成液中
の軽質な不純物である場合や、易重合性化合物中の重質
不純物の分離等の精製工程にも適用することができる。Therefore, it is preferable to install a steam cooling / condensing device near the top of the distillation column so as to make this portion as short as possible, and to maintain the piping at a temperature higher than the steam condensing temperature. For this purpose, it is preferable that a steam line or a hot water line be provided around the pipe so that the pipe can be heated as required, in addition to applying a heat insulating material to the pipe. The purification method of the easily polymerizable compound of the present invention is not only when the target substance to be obtained by distillation is an easily polymerizable compound, but also when the easily polymerizable compound is a light impurity in the reaction product liquid, The present invention can also be applied to purification steps such as separation of heavy impurities in easily polymerizable compounds.
【００１９】[0019]
【実施例】以下、実施例を用いて本発明を更に詳細かつ
具体的に説明するが、本発明はその要旨を超えない限
り、以下の実施例によって限定されるものではない。 ＜実施例１＞冷却・凝縮装置として熱交換用のチューブ
が鉛直になるように設置した多管式熱交換器を用いて、
粗アクリル酸ブチルの蒸留を行った。蒸留塔頂からのア
クリル酸ブチルの蒸気は熱交換器上部から導入し、冷却
は熱交換器の下部から導入した工業用水を胴部に流通さ
せることにより行った。この多管式熱交換器の熱交換用
チューブ上部に噴霧器を設置し、ｐ−メトキシフェノー
ルを０．１重量％含有するアクリル酸ブチルを毎時４２
ｋｇ噴霧して、凝縮面上を重合禁止剤を含む液が流下す
るようにした。なお、ｐ−メトキシフェノールの溶媒の
アクリル酸ブチルは、予め同様な方法で蒸留したものを
使用した。EXAMPLES Hereinafter, the present invention will be described in more detail and specifically with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist. <Example 1> As a cooling / condensing device, using a multi-tubular heat exchanger installed such that a tube for heat exchange is vertical,
Distillation of the crude butyl acrylate was performed. The vapor of butyl acrylate from the top of the distillation column was introduced from the upper part of the heat exchanger, and the cooling was performed by flowing industrial water introduced from the lower part of the heat exchanger through the body. A sprayer was installed above the heat exchange tube of this multi-tube heat exchanger, and butyl acrylate containing 0.1% by weight of p-methoxyphenol was added at 42 hours / hour.
kg, and the liquid containing the polymerization inhibitor was allowed to flow down on the condensation surface. The butyl acrylate used as the solvent for p-methoxyphenol was distilled in advance by the same method.
【００２０】蒸留塔としては上部には充填剤（ＩＭＴＰ
５０＃）が充填され、下部は１５段のデュアルフロート
レイが設置された形式のものを用いた。蒸留に用いた粗
アクリル酸ブチルとしては、触媒として強酸性イオン交
換樹脂（ＰＫ−２１６：三菱化学製）を使用し、８０
℃、１５０ｔｏｒｒの減圧下でアクリル酸とブタノール
とをエステル化反応させて得た反応液から、過剰アルコ
ール、酸成分、及びイオン交換樹脂を除去したものを使
用した。As a distillation column, a filler (IMTP) is provided at the top.
50 #), and the lower portion used was a type in which a 15-stage dual flow tray was installed. As the crude butyl acrylate used for the distillation, a strongly acidic ion exchange resin (PK-216: manufactured by Mitsubishi Chemical Corporation) was used as a catalyst, and
A reaction solution obtained by subjecting acrylic acid and butanol to an esterification reaction at 150 ° C. under a reduced pressure of 150 torr was used after removing excess alcohol, acid components, and ion exchange resin.
【００２１】この粗アクリル酸ブチル中には、ブタノー
ル０．０１重量％、ジブチルエーテル０．０５重量％、
重質成分４．１重量％及び若干量の酢酸ブチル、プロピ
オン酸ブチル及び重合禁止剤を含んでいた。蒸留は塔頂
温度４５℃、塔頂圧力１７ｔｏｒｒで実施し、塔底から
空気を少量供給しながら還流比を０．５として蒸留を行
った。原料の粗アクリル酸ブチルは蒸留塔の中段より毎
時２０００ｋｇ供給し、塔頂からは精製されたアクリル
酸ブチルを毎時１９００ｋｇ抜き出した。得られた精製
アクリル酸ブチル中のｐ−メトキシフェノール濃度は１
５重量ｐｐｍであった。この蒸留運転を１年間継続して
行った後、多管式熱交換器を点検したところ、全く重合
物は発見されず、また配管内部への重合体の堆積や閉塞
は見られなかった。In this crude butyl acrylate, 0.01% by weight of butanol, 0.05% by weight of dibutyl ether,
It contained 4.1% by weight of heavy components and some amounts of butyl acetate, butyl propionate and a polymerization inhibitor. Distillation was performed at a top temperature of 45 ° C. and a top pressure of 17 torr, and distillation was performed while supplying a small amount of air from the bottom with a reflux ratio of 0.5. 2000 kg / h of crude butyl acrylate as a raw material was supplied from the middle stage of the distillation column, and 1900 kg / hour of purified butyl acrylate was withdrawn from the top of the column. The concentration of p-methoxyphenol in the obtained purified butyl acrylate was 1
It was 5 ppm by weight. After performing this distillation operation for one year, the multitubular heat exchanger was inspected. As a result, no polymer was found, and no polymer was deposited or clogged in the piping.
【００２２】＜比較例１＞冷却・凝縮器として、熱交換
用チューブがほぼ水平となるように（出口側を水平から
約２°低くして）設置された多管式熱交換器を用いたこ
と以外は、上記実施例１と同様にしてアクリル酸ブチル
の精製を行った。６ヶ月間連続運転した後に熱交換器内
部を点検したところ、熱交換用チューブの約７０％に当
たる本数が、重合物により閉塞しており、運転の継続は
困難な状況となっていた。<Comparative Example 1> As a cooling / condenser, a multi-tube heat exchanger was used in which a heat exchange tube was installed so as to be substantially horizontal (the outlet side was lowered by about 2 ° from horizontal). Except for this, butyl acrylate was purified in the same manner as in Example 1 above. When the inside of the heat exchanger was inspected after the continuous operation for 6 months, it was found that about 70% of the tubes for heat exchange were blocked by the polymer, and it was difficult to continue the operation.
【００２３】＜実施例２＞冷却・凝縮装置として熱交換
用のチューブが鉛直になるように設置した多管式熱交換
器を用いて、粗アクリル酸水溶液の蒸留を行った。蒸留
塔としては段数４０段の棚段塔を用い、この塔頂直近の
塔頂と同じ高さの位置に熱交換器を設置し、蒸留塔塔頂
から冷却器に至る配管は、スチームラインをその外周に
接して設けて加熱することにより、蒸気の凝縮温度より
高い温度に維持するとともに、その周囲を保温材で被覆
した。蒸留は、塔頂温度７０℃、塔頂圧力７０ｔｏｒ
ｒ、及び還流比２の条件で行い、塔頂液を毎時６．６ｋ
ｇの割合で還流した。また、蒸留中は熱交換用のチュー
ブの上部から、ハイドロキノンとフェノチアジンのアク
リル酸溶液をそれぞれ毎時１ｇ、酢酸銅が毎時０．１ｇ
の割合で供給されるように噴霧することにより、これら
の重合禁止剤が凝縮面上を流下するようにした。<Example 2> A crude acrylic acid aqueous solution was distilled using a multi-tube heat exchanger as a cooling / condensing device in which a heat exchange tube was installed vertically. As a distillation column, a tray column with 40 plates is used, and a heat exchanger is installed at the same height as the top of the column immediately adjacent to the top of the column. By providing and heating in contact with the outer periphery, the temperature was maintained higher than the vapor condensation temperature, and the periphery was covered with a heat insulating material. The distillation was performed at a top temperature of 70 ° C. and a top pressure of 70 torr.
r, and the reflux ratio was 2, and the overhead liquid was 6.6 k / h.
Reflux at a rate of g. During the distillation, the acrylic acid solutions of hydroquinone and phenothiazine were respectively 1 g / h and copper acetate 0.1 g / h from the top of the heat exchange tube.
The polymerization inhibitor was sprayed so as to be supplied at a rate of 1%, so that these polymerization inhibitors flowed down on the condensing surface.
【００２４】蒸留塔に供給した粗アクリル酸はプロピレ
ンを気相接触酸化して生成したガスを凝縮して得られた
アクリル酸水溶液をトルエンを用いて脱水したものを毎
時８．０ｋｇの割合で用いた。この粗アクリル酸中には
水０．３重量％、酢酸２．３重量％及びトルエン７．０
重量％が含まれていた。蒸留により、塔底から酢酸０．
１重量％、アクリル酸９８．２重量％及び重質分を含有
する液を毎時４．９ｋｇ、塔頂からは水０．７重量％、
酢酸５．４重量％、トルエン１７．０重量％を含むアク
リル酸を毎時３．３ｋｇ、それぞれ得た。この蒸留運転
を１週間連続して行った後、運転を停止し熱交換器及び
これに至る配管を点検したが、配管内及び熱交換用チュ
ーブとも重合物は見られなかった。The crude acrylic acid supplied to the distillation column was obtained by condensing a gas produced by oxidizing propylene in gas phase and dehydrating an aqueous acrylic acid solution obtained using toluene at a rate of 8.0 kg / hour. Was. This crude acrylic acid contains 0.3% by weight of water, 2.3% by weight of acetic acid and 7.0% of toluene.
% By weight. Acetic acid was removed from the bottom of the column by distillation.
4.9 kg / h of a liquid containing 1% by weight, 98.2% by weight of acrylic acid and heavy components, 0.7% by weight of water from the top,
3.3 kg / h of acrylic acid containing 5.4% by weight of acetic acid and 17.0% by weight of toluene were obtained. After performing this distillation operation continuously for one week, the operation was stopped, and the heat exchanger and the pipes leading to the heat exchanger were inspected, but no polymer was found in the pipes or in the heat exchange tubes.
【００２５】＜比較例２＞熱交換器の設置位置を蒸留塔
の塔底と同じ高さとし、また塔頂から熱交換器に至る配
管のスチームライン及び保温材を設けず、かつ重合禁止
剤含有液の供給位置も熱交換用チューブの下部にしたこ
と以外は実施例２と同様にしてアクリル酸の蒸留精製を
行った。一週間連続運転を行った後、運転を停止し塔頂
から熱交換器に至る配管及び熱交換器内部（熱交換用チ
ューブ）を点検したところ、配管内部と熱交換用チュー
ブ内部に重合物の付着が見られた。<Comparative Example 2> The heat exchanger was installed at the same height as the bottom of the distillation column, no steam line and heat insulating material were provided for the piping from the top to the heat exchanger, and the polymerization inhibitor was contained. Acrylic acid was distilled and purified in the same manner as in Example 2 except that the supply position of the liquid was also located below the heat exchange tube. After one week of continuous operation, the operation was stopped and the piping from the top to the heat exchanger and the inside of the heat exchanger (heat exchange tubes) were inspected. Adhesion was seen.
【００２６】＜結果の評価＞本発明方法を用いた実施例
１、２では冷却・凝縮器（熱交換器）及び蒸留塔からこ
れに至る配管内部における重合体の生成が抑えられて、
長期間の連続運転が可能であるが、一方、熱交換器の凝
縮面を鉛直にしなかった比較例１、或いは重合禁止剤を
熱交換器の凝縮面上を流下するようにしなかった比較例
２では、早い時期に重合体の生成が起こっている。<Evaluation of Results> In Examples 1 and 2 using the method of the present invention, the production of a polymer in the piping from the cooling / condenser (heat exchanger) and the distillation column to this was suppressed.
Comparative example 1 in which a long-term continuous operation was possible, but the condensing surface of the heat exchanger was not made vertical, or Comparative example 2 in which the polymerization inhibitor was not allowed to flow down on the condensing surface of the heat exchanger. Then, the formation of a polymer occurs at an early stage.
【００２７】[0027]
【発明の効果】本発明の精製方法を用いることにより、
易重合性の化合物の蒸留時の、冷却・凝縮器及び蒸留塔
からこれに至る配管における、重合体の生成やその付着
による設備・配管の閉塞等のトラブルの恐れを極めて少
なくすることができ、蒸留設備の長期連続運転が可能と
なるので、工業上著しく有用である。By using the purification method of the present invention,
In the distillation from the cooling / condenser and the distillation tower during the distillation of the easily polymerizable compound, the risk of troubles such as clogging of equipment / piping due to the production of polymer and the adhesion of the polymer can be extremely reduced. Since the long-term continuous operation of the distillation equipment becomes possible, it is extremely useful industrially.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ テーマコート゛(参考） Ｃ０７Ｃ 51/50 Ｃ０７Ｃ 51/50 57/075 57/075 67/54 67/54 67/62 67/62 69/54 69/54 Ｚ (72)発明者 坂倉 康之 三重県四日市市東邦町１番地 三菱化学株 式会社四日市事業所内 Ｆターム(参考） 4H006 AA02 AD11 AD41 BD82 BD84 BS10 ──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. 7 Identification symbol FI Theme coat ゛ (Reference) C07C 51/50 C07C 51/50 57/075 57/075 67/54 67/54 67/62 67/62 69 / 54 69/54 Z (72) Inventor Yasuyuki Sakakura 1 Tohocho, Yokkaichi-shi, Mie F-term in Yokkaichi Office of Mitsubishi Chemical Corporation (Reference) 4H006 AA02 AD11 AD41 BD41 BD82 BD84 BS10
Claims (6)
して、蒸留塔の塔頂蒸気の冷却・凝縮装置を、その凝縮
面が鉛直となるように設置し、かつ該凝縮面上に重合禁
止剤を存在させることを特徴とする易重合性化合物の精
製方法。When distilling a liquid containing an easily polymerizable compound, an apparatus for cooling and condensing vapor at the top of a distillation column is installed so that the condensation surface is vertical, and polymerization is prohibited on the condensation surface. A method for purifying an easily polymerizable compound, characterized by including an agent.
重合禁止剤を含む液を噴霧することを特徴とする請求項
１に記載の易重合性化合物の精製方法。2. The method for purifying an easily polymerizable compound according to claim 1, wherein a liquid containing a polymerization inhibitor is sprayed on the upper part of the condensation surface of the vapor cooling / condensing device.
近に設置することを特徴とする請求項１又は２に記載の
易重合性化合物の精製方法。3. The method for purifying an easily polymerizable compound according to claim 1, wherein the vapor cooling / condensing device is installed immediately near the top of the distillation column.
の入口に至る配管を、蒸気の凝縮温度より高い温度に維
持することを特徴とする請求項３に記載の易重合性化合
物の精製方法。4. The method according to claim 3, wherein the piping from the top of the distillation column to the inlet of the vapor cooling / condensing device is maintained at a temperature higher than the vapor condensation temperature. Purification method.
リル酸、アクリル酸エステル及びメタクリル酸エステル
からなる群から選ばれる少なくとも１種の化合物である
請求項１〜４のいずれか１項に記載の易重合性化合物の
精製方法。5. The method according to claim 1, wherein the easily polymerizable compound is at least one compound selected from the group consisting of acrylic acid, methacrylic acid, acrylic acid ester and methacrylic acid ester. A method for purifying an easily polymerizable compound.
ル、ハイドロキノン、フェノチアジン及び銅化合物から
なる群から選ばれる少なくとも１種の化合物である請求
項１〜５のいずれか１項に記載の易重合性化合物の精製
方法。6. The easily polymerizable compound according to claim 1, wherein the polymerization inhibitor is at least one compound selected from the group consisting of p-methoxyphenol, hydroquinone, phenothiazine, and a copper compound. A method for purifying a compound.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11157641A JP2000344688A (en) | 1999-06-04 | 1999-06-04 | Purification of readily polymerizable compound |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11157641A JP2000344688A (en) | 1999-06-04 | 1999-06-04 | Purification of readily polymerizable compound |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2000344688A true JP2000344688A (en) | 2000-12-12 |
Family
ID=15654174
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11157641A Pending JP2000344688A (en) | 1999-06-04 | 1999-06-04 | Purification of readily polymerizable compound |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2000344688A (en) |
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